Automated Conflation for ArcGIS. User Guide. Version September ESEA 280 Second Street, Suite 270 Los Altos, CA 94022

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1 Automated Conflation for ArcGIS User Guide Version September 2015 ESEA 280 Second Street, Suite 270 Los Altos, CA 94022

2 Table of Contents WELCOME TO MAPMERGER... 5 USING MAPMERGER... 6 IMPORTING DATA... 7 Dynamic Attributes The MapMerger Layers Toggling between Two Different MapMerger Layer Views SAVING WORK IN PROGRESS CONFLATING POINT AND LINE DATA Overview of the Conflation Process Automatic Point Matching Manual Point Match Editing Automatic Line Matching Active Regions Match Regions Saving and Applying Match Strategies Using the Match Strategy Layer Viewing the Match Statistics Manual Line Match Editing Undoing and Redoing Conflation Operations Using the MapMerger Grid Adding Annotations to Matches Annotate Region The Match Status Table Merging the Data Using the Merge Parameter Layer Creating the Result Layer (non-sde source and target layers) Transferring the Z Elevation Coordinate to the Result Feature Class Creating the Result Feature Class (SDE source or target feature classes) Adjusting Other Source Layers MapMerger Attributes Metadata Viewing the MapMerger Log CONFLATING POLYGON LAYERS Importing Polygon Data Polygon Alignment Polygon Attribute Transfer RAPID CHANGE DETECTION SAVING MATCH INFORMATION IMPORTING MATCH INFORMATION IMPORTING ANCHOR POINT INFORMATION ADVANCED MAPMERGER CONFIGURATION Point and Line Match Settings Data Settings Spatial Adjustment Settings Auto Save Settings USING THE RESOURCE FILE Setting the Grid Cell Size Setting Default Attribute Values Treating Attribute Values as Null or Blank Controlling Which Valence Nodes are Used During Node Seeding i

3 Setting Default Result Attribute Values Setting the Default Z Elevation Value Ignoring Attributes when Removing Pseudonodes THE ATTRIBUTE MATCHING FILE INDEX ii

4 Table of Figures Figure 1. MapMerger Auto Conflate and MapMerger Manual Conflate toolbars...7 Figure 2. Importing data into MapMerger....8 Figure 3. Advanced data import settings....9 Figure 4. Creating a tile layer Figure 5. A 4 x 4 tile layer Figure 6. Specifying attributes to import Figure 7. Setting the unique identifier Figure 8. Specifying dynamic attributes for import Figure 9. Specifying the Address dynamic attributes Figure 10. Specifying the Address dynamic attributes Figure 11. Source and target data shown in the map display area after data import Figure 12. The Automatic Point Matching dialog Figure 13. Match scenario example where topologies do not match Figure 14. Using attributes to assist with matching in the Automatic Point Matching dialog...20 Figure 15. A point mismatch...21 Figure 16. Automatic Point Matching dialog - Ready for point match cycle # Figure 17. A one-to-many line match situation Figure 18. The Automatic Line Matching dialog Figure 19. Line matching without and with partial line matching Figure 20. Line match results Figure 21. Spatially adjusted source (in purple) Figure 22. Spatially adjusted source after line matching Figure 23. Active region example...28 Figure 24. Saving an active region...29 Figure 25. Urban match regions...30 Figure 26. Inverted urban active regions...31 Figure 27. The current strategy Figure 28. Example of local strategies for urban and rural areas...33 Figure 29. Attribute table for a Match Strategy Layer...33 Figure 30. Choosing which match strategy layer to execute Figure 31. Viewing the match statistics Figure 32. Multiline match selection Figure 33. The Exclude Feature window Figure 34. An offset intersection (colored red) selected for exclusion Figure 35. The Annotate Target Feature dialog that appears after right clicking while using the line match or split line tool Figure 36. The Annotate Highlighted Features dialog Figure 37. The Match Status Table Figure 38. The Group Check selection window Figure 39. The Merge dialog Figure 40. Default Attribute Transfer dialog example when target layer is not an SDE geodatabase iii

5 Figure 41. Default Attribute Mapping dialog when the target layer is an SDE geodatabase feature class Figure 42. Alignment Type dialog showing two different types of alignment methods...49 Figure 43. Attribute Mapping Selection where attribute mappings are chosen that will be examined for possible differences Figure 44. Change Detection Window...51 Figure 45. Attribute difference highlighted Figure 46: Resolving differences: Steps to take...53 Figure 47. The Show Attributes window...54 Figure 48. A topology break symbolized with a colored circle in the merged map Figure 49. Attribute table for a Merge Parameter Layer...56 Figure 50. Selecting the merge parameter layer to execute Figure 51. Creating the result in a file geodatabase Figure 52. Overwriting an existing feature class Figure 53. Overwriting a portion of an existing feature class Figure 54. The change detection layers Figure 55. Confirming that the Z coordinate will be transferred to the result Figure 56. Choosing how to create the result feature class when the target is a feature class in an SDE geodatabase Figure 57. Choosing whether to create a new file geodatabase with new attributes Figure 58. Selecting layers for adjustment Figure 59. The MapMerger Result Details table Figure 60. The MapMerger Log window with pop-up menu Figure 61. Choosing the polygon conflation type Figure 62. Choosing the type of polygon alignment...65 Figure 63. Creating the result polygon layer Figure 64. Automatic matching for rapid change detection Figure 65. Selecting the attribute mappings that will be reviewed for differences during rapid change detection Figure 66. Creating the change detection map...67 Figure 67. The rapid change detection difference map layer Figure 68. The Save Match Information dialog Figure 69. The Import Match Information dialog Figure 70. The Import Anchor Point and Line Match Information dialog Figure 71. Settings that control point and line matching Figure 72. Advanced data import configuration settings Figure 73. Settings that control the spatial transformation Figure 74. Settings that control Auto Save iv

6 WELCOME TO MAPMERGER Welcome to MapMerger, the premier ArcGIS extension for vector map conflation. MapMerger automates conflation by providing tools for: Attribute transfer: MapMerger will transfer attributes from an intelligent map with rich attribution to a beautiful map with good geometry. The result is a map that is both beautiful and intelligent, combining the best geometry and attribution that the source maps have to offer. Map densification: MapMerger will densify a map by adding and connecting features from one map onto another map. Map alignment: MapMerger will precisely align two maps with one another. Whereas the common approach to aligning maps with a GIS involves rubber-sheeting one map onto the other, MapMerger accomplishes an exact alignment by having features sharing their geometries. Map synchronization: MapMerger will synchronize a source map with a target map. Source and target features that have matching geometries but different attribute values are found and listed. Either source or target attributes can be transferred to the result. Change detection: MapMerger will rapidly compare two versions of the same map to identify and show changes in geometry and attribution. 5

7 USING MAPMERGER The MapMerger extension is composed of two toolbars: 1) the MapMerger Auto Conflate toolbar, which initiates data import, automatic point and line matching and creating the result layer, and 2) the MapMerger Manual Conflate toolbar, which contains tools for editing point and line matches (figure 1). Note that default colors for the source and target maps are best viewed against a dark background. Right click on the display to bring up the Data Frame Properties. Select the Frame panel and choose a dark background. 6

8 Manual Conflate Toolbar Buttons Auto Conflate Toolbar Buttons import match information import anchor points save match information configure import source and target execute strategy layer rapid change detection auto point match auto line match merge source with target write result layer adjust layers save or apply match strategies reset conflation show log file show conflation progress about MapMerger clear active region select active region match status table add multiline match add line match add point match annotate region multiline delete match delete match exclude feature re-include feature lock down orphans toggle anchor point split line show attribute values undo redo launch user guide Figure 1. MapMerger Auto Conflate and MapMerger Manual Conflate toolbars Importing Data The first step in a conflation project is to select the source and target feature classes to import into MapMerger. The role of the source and target data depends on the type of conflation being performed. MapMerger will either 1) transfer attributes from the source to the target, 2) align the source geometry to the target geometry or 3) synchronize the source with the target. When 7

9 the conflation is complete, MapMerger will create a result feature class in a file geodatabase or an SDE geodatabase (if SDE data is imported). To import data, click the Import Data button ( ) on the Auto Conflate Toolbar. In the Import Data dialog, choose the source and target feature classes. Choose a polygon clip layer when you want to conflate a geographic subset of the features in the source and target feature classes. MapMerger will use the polygons in the clip layer to extract in "cookie-cutter" fashion sections of the source and target data for conflation. To create the conflation result, MapMerger will either create an entirely new feature class, or overwrite an existing feature class, or modify a region in an existing feature class. If the intent of the conflation is to modify a region in an existing feature class, then select Yes for Will the conflation results be written to an existing feature class? MapMerger will then remind you to choose a clip layer (if one has not been chosen already). Only data overlapping the clip polygon will be imported and only result data that overlaps the clip polygon will be written to the result feature class. Figure 2. Importing data into MapMerger. Press the Advanced button to specify advanced data import settings. 8

10 Figure 3. Advanced data import settings. MapMerger's advanced data import settings provide the following capabilities: Remove target pseudonodes. Remove nodes from the target feature class that separate two features with identical attribute values. This setting defaults to off. Remove source pseudonodes. Remove nodes from the source feature class that separate two features with identical attribute values. This setting defaults to off. Target snap distance. Close gaps and remove overshoots (also known as dangles) in the target data that are less than the target snap distance. The locations of the gaps and dangles that are removed are listed in the log file. Source snap distance. Close gaps and remove overshoots (also known as dangles) in the source data that are less than the source snap distance. 9

11 Maximum vertices per line feature. This parameter will limit the number of vertices per line feature. The default value is 400. Maximum bend angle. This parameter will cause line features to be split where they bend more than the maximum bend angle. Seed distance. This parameter causes a node to be added wherever there is a node in the other map within this seed distance. Node seeding can improve the results of automatic matching in certain scenarios where one map has many more nodes than the other. Closest allowed node. Node seeding will not occur if there is an existing node within the distance specified by this parameter. Seed nodes in target. Add nodes in the target map wherever there is a node in the source map that is within the Seed distance from a target line feature and further than the Closest allowed node distance from an existing target node. Seed nodes in source. Add nodes in the source map wherever there is a node in the target map that is within the Seed distance from a source line feature and further than the Closest allowed node distance from an existing source node. Geometric tolerance. Map elements must be separated by a distance greater than the geometric tolerance in order for them to be considered separate entities. By default, MapMerger calculates the geometric tolerance during data import. Explicitly setting the geometric tolerance will override the automatic calculation. True arc sample interval. True arcs are feature geometries that are described by a mathematical formula rather than a series of vertices. MapMerger creates vertices to store true arcs by sampling true arcs at this interval. Smaller intervals result in higher accuracy but at the expense of increased memory usage. The interval is in units of meters. Clicking the Restore Defaults button will return the dialog to the default state shown in figure 3. Large data sets should be divided into smaller regions and conflated individually to improve performance and manageability. MapMerger makes it easy for very large data sets to be tiled (divided into equal rectangular portions) and managed. The Create Tiles button (figure 2) brings up the Create Tiles dialog (figure 4) that is used to either create a grid that is used for tiling or for reading a pre-existing tiling feature class. To create a new tiling layer, specify the number of rows and columns for the grid and press the OK button. Alternatively you can browse to a preexisting tiling feature class. A tiling feature class must be a polygon feature class with an integer field named tile that is given a value corresponding to the tile number. A tile layer consisting of a grid that is 4 x 4 is shown in figure 5. 10

12 Figure 4. Creating a tile layer. Choose the tile number for the polygon clip layer in order to import only the source and target data that overlap that tile (figure 5). Figure 5. A 4 x 4 tile layer. Checking the Specify attributes to import box in the Import Data dialog will direct MapMerger to show the Import Attributes dialog after the OK button is pressed. Attributes that can assist in automatic matching need to be imported into MapMerger. For example, if both the source and target are road feature classes that contain a road name attribute, then road name attributes should be imported in order for MapMerger to use road names to assist with automatic matching. Importing attributes also increases the speed in which they can be analyzed for change detection, a part of the synchronization process in which matching source and target features have their attribute values compared to see if they are different. 11

13 Figure 6. Specifying attributes to import. Choose attributes to import by selecting the attributes from the source and target lists and then press Add to move the attributes to the selected attribute tables on the right. Press the Remove button to remove attributes from the selected list. Figure 7. Setting the unique identifier. A unique identifier is an integer attribute that is used to uniquely identify a feature. Some data sets such as NAVTEQ with their Link ID and TIGER with their TLID have unique identifiers that must not be duplicated. By selecting the name of the unique identifier, MapMerger will 12

14 automatically assign a unique number to new features created in the result map. Features may have been created by adding new source features or by splitting source or target features during the conflation. Dynamic Attributes The value of a typical attribute does not depend on the direction or length of the associated feature s geometry. An attribute whose value is invariant with respect to changes in direction or length is called a scalar attribute. Some attributes have a complex relationship to the associated spatial entity. A change in direction or length will require a change in the attribute value. Sometimes these attributes work in conjunction with other attributes to describe a property of a feature. MapMerger will assume every attribute is scalar unless the user supplies information indicating which attribute has a complex nature. Checking the Set dynamic attributes box in the Import Data window will direct MapMerger to show the Dynamic Attributes dialog after the OK button is pressed. Dynamic attributes provide a mechanism for relating specific attribute names to the length and direction of line features enabling MapMerger to automatically update the dynamic attributes when a feature is divided or merged or when the direction is inverted during the conflation process. Figure 8. Specifying dynamic attributes for import. Right clicking over the source or target tables will display a context menu that lists the different dynamic attributes supported by MapMerger. The following attribute relationships are supported: Address: Creates a relationship between four attribute names whose attribute values are integer. This relationship is designed to maintain numeric street addresses. When the 13

15 direction of the associated feature is inverted, this relationship causes the attribute values to be swapped through a four-corner swap with values being swapped to the opposite corners. In addition, if the associated feature is divided during the conflation process, then the address values are adjusted in proportion to the ratio of the new length to the old length, while maintaining the odd/even property of the original data. Left/Right Attribute Pairs: Creates a relationship between two attribute names that causes the attribute values to be swapped when the direction of the associated feature is inverted. Length: This is a single attribute relationship to the associated feature that modifies the numeric value of the attribute proportional to any change to the geometric length of the associated feature. For example, if the feature is split, then the length attribute (as defined in the directional attribute file) will be adjusted according to the ratio of the new geometric length divided by the old geometric length. Milepost: Creates a relationship between two attribute names and the associated feature that modifies the numeric value of the attributes proportional to any change to the geometric length of the associated feature. Each context menu selection displays a dialog box that enables dynamic attribute names to be inputted. An example of entering the Address dynamic attributes is shown below. Figure 9. Specifying the Address dynamic attributes. Selecting the Address dynamic attributes and then pressing the OK button will show the Dynamic Attributes dialog now populated with the Address attributes. This is shown in figure 10. Remove a dynamic attribute by selecting the dynamic attribute to be removed and pressing the delete key. 14

16 Figure 10. Specifying the Address dynamic attributes. After OK is selected, a series of messages are written to the MapMerger log file and the ArcMap status window describing the data import process. MapMerger will import data from either shapefile, personal geodatabase or file geodatabase data formats. MapMerger will also import SDE geodatabase feature classes. The Arc Coverage format is not supported. MapMerger ensures that every intersection in the imported data has a node. Nodes at intersections that did not have nodes in the original data, such as overpasses, can be removed later in the conflation process (see Merging the Data). The MapMerger Layers MapMerger creates a group of layers in the ArcMap table of contents after data import is completed. This group of layers controls the conflation data display. The MapMerger layers are similar to other ArcMap layers in that their color and symbology can be modified. Unlike ArcMap layers, the MapMerger layers are not associated with a data file but rather they represent MapMerger data stored in computer memory. It is important that the original source and target layers and the MapMerger layers not be moved, deleted or modified in any way during a conflation session. Modifying these layers can prevent MapMerger from completing the conflation and can result in lost work. The MapMerger layers are organized within the MapMerger group layer as shown in figure

17 Figure 11. Source and target data shown in the map display area after data import. Toggling between Two Different MapMerger Layer Views The view of MapMerger layers that are currently visible is saved by clicking on the display area and typing Alt-S. Typing Alt-T will toggle between the current MapMerger layer view and the saved view. This keyboard control of the displayed MapMerger layers is very useful during visual scans of the conflation results. Saving Work in Progress Saving the ArcMap map (.mxd file) will automatically save the state of the conflation session so that work can be resumed the next time the.mxd file is opened. MapMerger configuration parameters along with the imported data layers and the match information are saved to the.mxd file. Conflating Point and Line Data In the following discussion, match points refer to pairs of matched target and source points. In a point feature layer, the match points correspond to actual point features. In a line layer, the 16

18 match points correspond to matched line feature end points or line intersection points. An anchor point pair or link vector are matched points that MapMerger uses to create a spatial transformation that brings the source data into better alignment with the target data. Overview of the Conflation Process The optimal methodology for performing a conflation project depends on the goals of the conflation project and the characteristics of the data being conflated. For example, transferring attributes from a source to a target feature class could include these steps: 1) Extract a small region to perform a pilot conflation. 2) Use the ArcMap Measure tool to measure a typical separation between matching source and target intersections. 3) Perform a few cycles of automatic point matching. First perform point matching with a small search distance to find the high confidence matches. Then perform automatic point matching using a search distance larger than the typical separation measured in step 2. If applicable, choose an attribute to assist with matching. 4) Perform automatic line matching using the same settings as the last automatic point match cycle. 5) Save the match strategy. 6) Correct the results of automatic line matching using the line match editing tools. 7) Merge the data to create the result MapMerger layer. 8) Check the merged layer for anomalies and correct errors where required by applying the match editing tools to the matched source and target. Merge again after the errors are corrected. 9) Create the result ArcMap data layer. 10) Check the result ArcMap layer. 11) Proceed to conflate the entire project region using the match strategy saved during the pilot conflation. This is an example of a match strategy for matching a particular pair of feature classes to transfer attributes. The match strategy refers to the series of automatic point and line match cycles that are used for automatic matching (this is not to be confused with the attribute match strategy parameter). The match strategy is chosen in accordance to the particular characteristics of the source and target data being conflated, so as to achieve the greatest number of correct matches possible. Each conflation project requires that strategies be developed that are based on the characteristics of the data being conflated. It is important to first experiment with matching a 17

19 pilot region using various match parameters and then apply the best strategies for matching the entire data set. Automatic Point Matching Point matching can be done at any time during a conflation, or not at all, but is typically the first step of a conflation. Achieving good point match results is vital to obtaining good line match results. There are many automatic point match parameters that can be modified and experimented with in order to achieve optimal match results. It is sometimes advantageous to first manually add a few point matches (see the subsection Manual Point Match Editing below). A few manual point matches can bring two poorly aligned maps into better alignment and improve the performance of automatic point matching. Click the Auto Point Match button ( Point Matching dialog. ) on the Auto Conflate Toolbar to show the Automatic Figure 12. The Automatic Point Matching dialog. Parameters entered into this dialog are used by the automatic point matching conflation algorithms. Search Distance: This value limits the search radius for candidate match points. A pair of target and adjusted source points will not be considered candidates for matching if more than this distance separates them. If this distance is too large MapMerger may find unwanted matches. If it is too small MapMerger will not find enough matches. Use the Measure tool on ArcMap's Tools toolbar for assistance in determining an appropriate match distance. The search distance is in units of meters. 18

20 Topo vs. Distance Weight: This value is set with a slider bar. The value determines how relevant topology is in determining a point match. MapMerger uses both distance and topology criteria in determining point matches. In this context topology refers to the number and angle of line features incident at a point. There are situations where data will match better without using topology criteria. An example is a sparse road layer containing major arteries being matched to a dense road layer. In this scenario the match scenario depicted below may frequently occur. Figure 13. Match scenario example where topologies do not match. Based on topology criteria, MapMerger will not match this because the intersection in the red map has a valence of 3 and the node in the yellow map has a valence of 2. A low value for Topo vs. Distance Weight will direct MapMerger to be less inclined to match points that have a different valence (the number of line features incident to the point). A high value will ignore the topology measure and only use distance to determine the point match criteria. Match valence 1, 2, 3, three or more nodes: Checking one of these boxes will direct MapMerger to consider nodes of the specified valence for point matching. This can be useful when only nodes of a certain type are to be matched such as valence one cul-de-sacs. Include new point matches in spatial transformation: Checking this box will cause new point matches found during automatic matching to be used for building the spatial transformation. Show attribution settings: Pressing the + sign will expand the window to show the attribute matching settings. These settings control how attributes can be used to assist with the matching. 19

21 Figure 14. Using attributes to assist with matching in the Automatic Point Matching dialog. Attribute Matching: The point matching algorithms can use attributes of line features connected to points to assist in the match comparison. Select the attribute name for the attribute to be used. Only one attribute can be chosen per match cycle. Attribute Match Strategy: Select the attribute match strategy to be used to match the target and source attributes. Possible strategies are 1) exact string match, 2) case insensitive string match, or 3) a street name matching function that allows some mismatch between common road prefixes (N, North,...) and common road suffixes (St., street,...). The road name option does not favor exact matches over these close matches. See the section titled The Attribute Matching File for a more detailed explanation of attribute matching. Attribute Weight: The attribute weight is set with the slider bar. The attribute weight determines how relevant the attribute match is in determining a point match. 20

22 Allow matches only when attributes match: Checking this box will direct MapMerger to only match points when the match attribute of the line features adjacent to the point also match. Use this setting when there is high confidence in the attribute being used to assist in matching. For instance, when the road name attribute in both the source and the target is consistent and accurate. When this box is checked, MapMerger will not match features in which the attribute used for matching is unset (null value). The results of point matching are shown in the map display. Lines are drawn that represent link vectors that connect matching target and source points. The link vectors belong to either the spatial adjustment links or other links MapMerger layer within the group layer named Links. View the Adjusted Source sub-layer (see section on Viewing the Adjusted Source) to see how the source map would be adjusted by a spatial transformation defined by the link vectors. This layer is changed each time a link vector is added or deleted from the spatial transformation. This depicts, in a sense, the progress of the current conflation process based on the matches added thus far. The figure below shows a map region with one anchor point (green connecting line) and one match point (aqua connecting line). This mismatch occurred due to poor attribution in the region; some of the line features had missing attributes. Crossing link vectors such those shown in this example give a strong indication that manual review is needed. Figure 15. A point mismatch 21

23 Figure 16 shows the Automatic Point Matching dialog after one match cycle. The Cycle# 2 value in this example indicates that the next point matching cycle will be the second. Additional automatic match cycles will not remove any matches previously made. In the examples shown, the first match cycle invoked the Allow matches only when attributes match option while the second match cycle removed that criteria (figure 16). In this case, the strategy is to find in the first match cycle the high confidence matches where the attributes definitely match, and reduce the criteria in the second match cycle to find matches where the attributes might not match (one of the roads may not have its road name set or may spell the road name differently). Figure 16. Automatic Point Matching dialog - Ready for point match cycle #2. Manual Point Match Editing Point matches can be manually added or deleted at any time during the conflation. The results of automatic point matching should be reviewed to make sure that the automatic point match 22

24 parameters generated good results. It is not necessary to correct the point match results before continuing with automatic line matching. If the automatic point match results are sufficiently accurate then it may save time to proceed with automatic line matching and manually edit the match results in one pass after automatic line matching is complete. Link vectors that are in the spatial transformation determine where the unmatched source features (orphans) will be added in the result map. Therefore it is important to remove any unwanted link vectors from the transformation if the result map will include orphans. It is also important to have accurate link vectors if the spatial transformation will be used to move other source feature classes to align with the target map. Deleting Point Matches: Selecting the Delete Match tool ( ) located on the MapMerger Manual Conflate toolbar enables match point deletion. The mouse cursor will change to a bulleye mouse cursor. To delete point matches, either draw a box that overlaps the link vectors, or click on link vectors that connect unwanted match point pairs. The selected point matches will be removed. MapMerger will not rematch deleted point matches during subsequent automatic match cycles when the point matches were removed by clicking on their links. However, MapMerger will rematch point matches that were removed using the delete match tool s stretch box. This to allow matches in a region to be removed then automatically matched again with a specific strategy more suited to that region (see the section on Match Regions). Adding Point Matches: Selecting the Add Point Match button ( ) in the MapMerger Manual Conflate toolbar starts manual point matching and is indicated by a pencil-shaped mouse cursor. First click on one desired match point on either the target or source map. This will cause a sticky-line to follow the cursor. Place the cursor over the other desired match point and click to complete the operation. This action inserts the match point pairs for the next and all subsequent match cycles. By default, MapMerger uses manually added point match pairs as anchor points in building the spatial transformation that aligns the source map with the target map. Anchor point pairs that are not point matches can also be added to the transformation. To create a new anchor point pair that is not a matched point pair (called a pure link vector), first click on a source or target map feature then click anywhere within the map extent while holding down the shift key. The anchor point pair will be added to the spatial transformation. Toggling Anchor Points: Matched point pairs are not always useful as anchor points. It is possible that a particular source and target point pair happens to match but their spatial relationship is very different than the surrounding points. In such a case, it is detrimental to add the matched point pair to the spatial transformation as it would cause the neighboring points to misalign. Selecting the Toggle Anchor Point button ( ) in the MapMerger Manual Conflate toolbar starts the toggle anchor point tool. Clicking the pencil-shaped mouse cursor on a link vector connecting an anchor point pair will remove it from the transformation. Clicking on the link vector again will add it back to the transformation. Alternatively, drawing a box that overlaps a group of link vectors will toggle the link vectors that lie within or overlap the borders of the box. 23

25 Locking down unmatched features (orphans): Unmatched source features are referred to as orphans and unmatched target features are referred to as target orphans. Orphan features are added to the result map in their spatially adjusted locations. Selecting the Lock/Unlock Orphans button in the MapMerger Manual Conflate toolbar will display a window asking whether to create identity link vectors at source or target orphans. Identity link vectors are link vectors that start and end at the same point and thus prevent that point from being moved in a spatial transformation. The identity link vectors will lock the orphan features so that they are added to the result map at their original source location. Selecting the Lock/Unlock Orphans button again undoes the previous action by removing the identity links. Automatic Line Matching MapMerger performs both one-to-many and many-to-many line matching. When a single line matches to several lines, the single line will be broken into several lines so that the result is a series of one-to-one line matches. Line matching can be done at any time but results are generally better if there are point matches to start with. Figure 17. A one-to-many line match situation. Click on the Auto Line Match button ( Automatic Line Match dialog. ) on the MapMerger Auto Conflate toolbar to show the MapMerger s automatic match algorithms match the adjusted source to the target features. The adjusted source is moved into closer alignment with the target each time an automatic match cycle is completed. For this reason, the search distance used in line matching can usually be decreased from what was used in point matching. 24

26 Figure 18. The Automatic Line Matching dialog. Checking the Do partial line matching box will direct MapMerger to partially match line features. Figure 19. Line matching without and with partial line matching. This partial line match capability is useful when matching roads with cul-de-sacs and streams that match except near their headwaters. An example of line match results is shown in figure 20. The dark green represents matched target lines and the brown represents matched source lines. The yellow represents unmatched target lines and the orange represents unmatched source lines. Line match results are accessed through the MapMerger layers for the matched and unmatched source and target. Clicking on an already matched line with the Add Line Match tool will highlight the line features in the matched pair. 25

27 Figure 20. Line match results. Viewing the Adjusted Source The adjusted source map should be examined for areas where the adjusted source does not line up well with the target. This can indicate that there are mismatched or unmatched features that require manual match editing. 26

28 Figure 21. Spatially adjusted source (in purple). The spatially adjusted source data after line matching is shown in figure 22. The transformed matched source lines are colored dark purple and the transformed unmatched lines are shown in light purple. Figure 22. Spatially adjusted source after line matching. 27

29 Active Regions The Select by Rectangle ( ) and the Select by Polygon ( )tools enable areas called Active Regions to be selected for processing. When an active region is selected, features overlapping the region are shown unchanged while features outside the region are symbolized with a grey dashed symbol (figure 23). Click the Clear Active Region ( )button or click once anywhere on the map within the Select by Rectangle tool to clear the active region. The automatic and manual match tools as well as the merge tool affect only features within active regions. Figure 23. Active region example Right clicking while selecting an active region by rectangle or polygon will bring up a context menu with the following items: Choose the menu item or the keyboard equivalent to either clear the region, go to the previous or next active region, or to choose from one of these interactive selection methods: Create New Selection, Add to Current Selection, Remove From Current Selection or Select From Current Selection. Active regions composed of multiple rectangles or polygons can be created by holding down the shift key while creating a new selection or by setting the interactive selection method to add to the current selection. 28

30 The active region polygons can be saved to polygon shapefiles by selecting Save to polygon layer from the context menu. Active regions that area composed of multiple polygons will be saved to a layer with the polygons combined into one multipart polygon feature. The Save Active Region window will appear with a new polygon layer named activeregion1 as the default active region layer name. To change the layer name, click Browse and either select an existing active region layer or enter a new name. Check Link to match strategy file will cause a file selection window to appear for specifying the match strategy file to link the active region layer to. Check Include merge parameters to include the parameters from the last merge into the match strategy file. Linking to a match strategy file or including merge parameters is an easy way to create a polygon feature class that has all the fields required for either a match strategy feature class or a merge parameter feature class. The feature class can later be edited using the ArcMap editor. Figure 24. Saving an active region The active region shapefile has fields named invert, strategy and the merge parameter fields that are required for making a merge parameter layer. The invert field will have a value of 1 if the active region is inverted and only features outside the active region are active. The strategy and merge parameter fields enable the active region layer to be reused as either a match strategy layer or a merge parameter layer. Selected polygons in an existing polygon layer can be used as active regions by choosing Load selected from polygon layers. The polygons that are selected will be loaded as the active regions. Match Regions Automatic point and line matching apply only to features within the current active region. Creating active regions around features with specific characteristics, such as an urban area with streets in a grid pattern or a rural area with long winding roads, enable match strategies to be optimized and applied locally for improved matched results. A match region is an active region used in concert with a match strategy to optimize the performance of automatic matching. 29

31 Figure 25. Urban match regions An urban match strategy can be applied to a match region covering the cities to generate optimal matching for the urban areas. This urban match region can be inverted to become a rural match region (see the figure below) which can then be best matched with a rural match strategy. 30

32 Saving and Applying Match Strategies Figure 26. Inverted urban active regions Match strategies can be saved, restored and executed by MapMerger. Comparing saved match strategies for a pilot region can help in determining the best strategy for a conflation project. The match strategy can then be shared among users working on different parts of a project area. Click the Match Strategy toolbar button ( ) to manage match strategies. The Match Strategy window displays strategies in a tree format. In the figure below, the two cycles that have been completed in the current strategy are shown. The root of each strategy tree is the strategy name. Below the strategy name are branches for each automatic match cycle completed. The cycle is described by its type; point or line, and its search distance. Expanding a cycle branch displays the parameters used in that cycle. 31

33 Figure 27. The current strategy. Individual strategies are saved to an XML file with the extension of str. Use the Save Current Strategy button to save the current strategy. Use the Load button to load a saved strategy. A strategy is selected when all check boxes in its branch are checked. Checking the box next to a strategy root will check all boxes in that branch while unchecking the boxes in the other strategy branches. Only one strategy can be selected at a time. Checking a row in a cycle branch will automatically check all boxes in that branch as well as the box next to the cycle s strategy. Multiple cycles can be selected as long as they are within the same match strategy. Press the Remove button to remove a selected strategy. Press the Apply button to apply a selected strategy or the selected cycles. Applying a strategy or a group of selected cycles will cause MapMerger to execute the cycles in batch mode, in which each cycle will be executed in turn, without user intervention. Applying just one selected cycle will cause MapMerger to execute the cycle in interactive mode, in which the match dialog is displayed and can be modified prior to execution. There are two types of match cycles: global and local. Global cycles have been applied to the entire project extent, whereas local cycles have been applied to a match region. When a strategy or multiple cycles have been selected for execution, MapMerger will not execute the local cycles unless the Include local region cycles box is checked. 32

34 Figure 28. Example of local strategies for urban and rural areas Right clicking on a row will show a popup menu with the items Apply and Remove Strategy. Choosing to Apply will execute the cycle or strategy for the row selected. Choosing Remove Strategy will remove the selected strategy when the right click occurs on a strategy row. Using the Match Strategy Layer The Match Strategy Layer is a polygon layer that specifies match strategies for specific regions. Each polygon feature in a match strategy feature class has an attribute named Strategy that contains the path to a match strategy file. A match strategy layer can be any polygon layer with a Strategy text field. Figure 29. Attribute table for a Match Strategy Layer Use the Match Strategy Layer to store match strategies for specific regions in the map. Click the Execute Match Strategy ( ) button to automatically execute match strategy layer strategies for their match regions. 33

35 Figure 30. Choosing which match strategy layer to execute. Choose the match strategy layer from one of the layers in the table of contents. MapMerger will execute all the match strategies in the selected layer. Check the Include local region cycles to also run the match strategies that were originally applied to a match region. Viewing the Match Statistics A bar graph showing the current number of matches categorized by their type can be viewed by clicking the Show Match Statistics button ( ) on the Auto Conflate Toolbar. Figure 31. Viewing the match statistics. The number of line matches is shown in the upper bars and the number of point matches is shown in the lower bars. Each bar represents the total number of matches completed at the end of a succeeding match cycle. Each bar is separated into two parts that are colored differently; the automatic matches and the manual matches (colored in yellow). The first bar representing cycle 0 will show manual matches completed prior to the first automatic match cycle. Moving the mouse over a bar will cause the cycle number and the number of point and line matches for that cycle to be displayed. 34

36 A report summarizing the conflation progress is generated by clicking on the Create Report hypertext. After specifying the destination for the report, a comma delimited text file with extension.csv, will be created. An example of a report is shown below. Manual Line Match Editing Line matches can be manually added or deleted at any time during the conflation. The results of automatic line matching should always be reviewed and edited where necessary. The data should be browsed for regions that necessitate manual editing. The following are indicators of possible incorrect matching. Crossing link vectors that connect matched points: Matched point pairs that are not anchor points are colored differently than link vectors that connect matched points. MapMerger will remove a link vector from the transformation and color it differently if it crosses another link vector. This is often indicative of a mismatch. An anomalous link: Often a region shows a consistent offset between the source and target maps. The consistent offset will cause the matched point link vectors to be parallel. A mismatch will often stand out as a link that is in a different direction and has a different length than the vast majority of the surrounding links. Unmatched features: In MapMerger's default coloring scheme, unmatched source and target features stand out as brighter colored lines when viewing line match results. These features should be examined to ensure that they have been correctly left unmatched. Mismatches may occur because the source and target features are representing the same earth features at different scales. Overlaying the vector data on an orthorectified image of the conflation region can be helpful in resolving difficult match scenarios. The attribute value for the attribute used for automatic matching can be shown in a pop-up window during match editing by moving the mouse over a feature while holding the shift key down. For example, after road names are used to help with automatic matching, the road names 35

37 can be readily viewed during match editing by holding the shift key down and moving the mouse over road features. Deleting Line Matches: Line matches, point matches and added nodes may be deleted manually. Selecting the Delete Match tool ( ) located on the MapMerger Manual Conflate toolbar activates the delete match tool and is indicated by a bull-eye mouse cursor. In this mode, a line match can be unmatched by clicking on one of the incorrectly matched lines or by drawing a box that overlaps one of the incorrectly matched lines. Adding Line Matches: Selecting the Add Line Match button ( ) in the MapMerger Manual Conflate toolbar starts line matching and is indicated by a pencil-shaped mouse cursor. Click on one matched line for either the target or source map. The selected line is now highlighted in thicker line width. Place the cursor over the other desired match line and click and the operation is completed. This action adds the matched line pairs for the next and all subsequent match cycles. Clicking on an already matched line will highlight the line features in the matched pair. This is a very useful visualization tool and should be used extensively when reviewing line match results. It is possible to annotate special match situations by right clicking within the Add Line Match and Split Line tools. See the section titled Adding Annotations to Matches below. Splitting and Unsplitting a Line: Click on the Split Line button ( ) within the MapMerger Manual Conflate toolbar to split a line feature. Click the pencil shaped cursor at the location where the line is to be split. A dot is marked on the line to show the split location. A manual unsplit line can also be performed. Click on the Delete Match tool ( ) located on the MapMerger Manual Conflate toolbar. Place the bull-eye cursor over a line at the spot where the line feature is split. Clicking will remove the node that is splitting the line feature. The added nodes can also be removed by using the delete match tool to draw a box around the nodes that are to be removed. MapMerger will not allow matched lines to be split or unsplit. This tool will only unsplit the unmatched lines that have been split by a MapMerger operation. Multiline Selection: The Delete Multiline Match and the Add Multiline Match tools operate on selected chains of line features. Multiline match editing is a powerful tool that saves time when editing line match results. Select a chain of lines by first clicking near the start of the first line feature in the sequence. Then click a second time on this feature but this time at a location towards the direction that the chain will grow. The location of these two mouse clicks indicates the direction that the chain will be grown. The first click should be closest to the start of the chain and the second click should be towards the end of the chain. The initial line in the chain will be highlighted after these two clicks are completed. Extend the chain by clicking on another line in the chain. MapMerger will attempt to grow the chain to the selected line by continuing the chain in the straightest direction at each intersection. If MapMerger is successful in growing the chain to the line selected then the entire chain will be highlighted and a message indicating that the multiline has been extended will be shown in the status window. Alternatively, clicking on any line that is 36

38 adjacent to the end of the currently highlighted chain will also grow the chain. A chain cannot be grown if it loops upon itself or if it reaches the end of the map. Press the space bar to complete the multiline selection. Right clicking the mouse will undo the last multiline extend operation. An entire multiline selection can be undone with repeated right clicks. If a source chain has been completely selected and a target chain is being selected then repeated right clicks will undo the target chain selections first and then will undo the source chain selections. Close attention should be given to the status messages that appear while selecting multilines. The status line informs the operator if the multiline has been initialized and when the multiline selection is complete. Sometimes it may appear to the operator that a new multiline is being selected when MapMerger is still selecting the first line. Keyboard equivalents for ArcMap Pan/Zoom operations should be used during multiline match editing because clicking on a Pan/Zoom tool during multiline selection will cancel the multiline selection operation. Multiline Match Deletion: The Delete Multiline Match tool ( ) on the MapMerger Manual Conflate toolbar enables a chain of adjacent line matches to be deleted quickly and easily. The mouse cursor changes to a bull-eye upon starting the multiline match deletion tool. Select a chain of line features as described in the preceding section. Double-clicking will conclude the multiline selection and delete all line matches that occur within the selected chain of line features. Multiline Match Addition: A chain of adjacent lines can be matched to another chain of adjacent lines using the Multiline Match tool. Any previously matched lines in the selected line sequences will be deleted and rematched. Lines will be automatically split to ensure one-to-one matching. This tool can save time in manually adding line matches because it will automatically split and unsplit lines where required to ensure one-to-one matching. Start multiline matching by clicking the Multiline Match tool ( ) on the MapMerger Manual Conflate toolbar. Select the first chain of lines to be matched. Select the lines in the manner described in the preceding section describing multiline selection. Double-click to complete selection of the first line chain. Select the second line chain to be matched. After the second multiline is selected and highlighted, double-click to execute the multiline match operation. 37

39 Figure 32. Multiline match selection. Selecting features for exclusion: The Exclude Features tool ( ) on the MapMerger Manual Conflate toolbar is for selecting source or target features that should not be transferred to the merged map. Upon starting the Exclude Features tool, the mouse cursor changes to a bull-eye and the Exclude Features window is displayed. Figure 33. The Exclude Feature window. The Exclude Features window controls which features can be selected for exclusion and how they will be selected. Source and target features can be selected for exclusion only if their check box has been checked. The Multiline exclude check box controls how features are selected for exclusion. Checking the box will enable the exclude tool to select multilines for exclusion in the same manner that features are selected for multiline match addition and multiline deletion (see 38

40 the section on Multiline Selection). Pressing the space bar after a multiline is selected will exclude the features selected in that multiline. With the Multiline exclude check box unchecked, clicking on a feature will exclude it and the excluded feature s color will change (the default exclude color is red) denoting that it has been excluded. Holding the mouse button down and dragging will create a stretch box. Releasing the mouse button will exclude all the features that are either inside the box or overlapping the box depending on the Exclude features overlapping selection rectangle configuration setting. A feature that is selected with the Exclude Features tool can no longer be matched. The excluded feature will be excluded from the result map. A situation where this tool could be effectively used is shown in the figure below. Figure 34. An offset intersection (colored red) selected for exclusion. Figure 34 shows an offset intersection in the source data (orange-brown) that matches an intersection with no offset in the target data (green). In this situation, matching the section of source road (colored red) between the offset intersections to a section of target road would be an inaccurate solution. Likewise, leaving the section of road unmatched and transferring it to the result map would incorrectly cause the result road network to have a spurious road attached to the intersection. The correct solution is to leave the section of road unmatched and not transfer it to the result map. This is accomplished with the Exclude Features tool. 39

41 Selecting features for re-inclusion: Features that were selected for exclusion using the Exclude Features tool can be re-included using the Re-include Features tool on the MapMerger Manual Conflate toolbar. Upon starting the Re-include Features tool, the mouse cursor changes to a bull-eye and the Re-include Features window is displayed. The Re-include Features functions in the same way as the Exclude Features window described earlier, controlling which features can be selected for re-inclusion and how they will be selected. The features that can be re-included are controlled by the Source and Target check boxes. Checking Multiline re-include will cause the tool to re-include the selected multilines. When the Multiline re-include check box is not checked, clicking on an excluded feature will re-include it. Holding the mouse button down and dragging will create a stretch box. Releasing the mouse button will re-include the features that were excluded either inside the box or overlapping the box depending on the Exclude features overlapping selection rectangle configuration setting. Undoing and Redoing Conflation Operations Conflation operations can be undone by clicking the Undo button ( ) on the Manual Conflate Toolbar. This will undo the last conflation operation whether it was a manual operation (e.g., adding or deleting a match) or an automatic operation (e.g., running a point or line match cycle). The operations that can be undone include: adding or deleting matches, toggling link vectors, splitting lines, doing point or line match cycles, and deleting or undeleting features. Up to the last 100 operations can be undone. Once an operation is undone, it can be redone by clicking the Redo button ( ) on the Manual Conflate Toolbar. The entire conflation, all automatic match cycles, all manual matches and all MapMerger edit operations can be undone by pressing the Reset Conflation button ( ) on the Auto Conflate Toolbar. Using the MapMerger Grid MapMerger can show a grid of cells to help keep track of the review process. The current grid cell number (row, column) is shown in the ArcMap status window during match editing. The grid cell size is controlled with the MapMerger resource file as described in the section Using the Resource File. The grid is made visible by turning on the Grid MapMerger layer. Adding Annotations to Matches It is often useful to annotate special match situations. Right clicking on a line feature will show a dialog that provides a mechanism for setting the value of a special attribute named MM_TARGET_NOTE for target features and MM_SOURCE_NOTE for source features. This attribute takes a text value that can be used later when reviewing the conflation results to quickly locate special match situations. The ability to annotate a feature by right clicking is available within the Add Line Match and Split Line tools. 40

42 Figure 35. The Annotate Target Feature dialog that appears after right clicking while using the line match or split line tool.. Annotate Region Multiple features can be annotated simultaneously with the Annotate Region tool ( ). Activating the Annotate Region tool displays the Annotate Highlighted Features window and changes the cursor to be pencil-shaped. Annotation text is entered for MM_SOURCE_NOTE and MM_TARGET_NOTE. Pressing the Highlight button will highlight all features that have the annotation text. Pressing the Clear button will clear the highlighted features from the display. Clicking on a feature will highlight that feature. Drawing a box or polygon on the map will highlight features that overlap the box. Additional non adjacent areas can be highlighted simultaneously by holding the shift key down while drawing another box. Pressing the Apply button will apply the annotation text entered for MM_SOURCE_NOTE and MM_TARGET_NOTE to the highlighted features. The Match Status Table Figure 36. The Annotate Highlighted Features dialog. The Match Status Table ( on the Manual Conflate Toolbar) lists information that helps track progress during match editing. The ArcMap feature ID, grid cell, annotation note, match type and match status is displayed for each source and target feature. The table can be sorted by clicking a column header. Annotation can be entered directly into the table. Checking Zoom to selected feature will cause the feature in the selected row to be displayed and highlighted. 41

43 Clicking Save As will save the contents to a text file. Clicking on a feature with MapMerger s Show Attributes tool will scroll to and highlight the corresponding row in the Match Status table. Figure 37. The Match Status Table. The Match Status Table can be used to help keep track of match editing. The right most column is used to check off unmatched features that have been edited or reviewed. Prior to merging, matched features are not checkable and are marked with an X. Unmatched features are originally unchecked, and are represented with an empty yellow box. After an unmatched feature is reviewed, clicking on the box will place a check mark in the box, showing that the feature has been reviewed. Clicking again on the box or pressing the space bar will change the box back to being unchecked. The column can be sorted to group together the features that have yet to be reviewed. A tally of checked, unchecked source and unchecked target is shown beneath the table. After merge, some matched features may become checkable. Check Merged needing review to view only the rows that are matched but checkable. These rows reference matches that are near a topo break. The matches in this region should be reviewed and rematched if necessary. Clicking the Group Check button enables a group of unmatched features to be simultaneously marked as reviewed. 42

44 Figure 38. The Group Check selection window. Choose to select a rectangle or polygon region. Use the pencil cursor to draw a region around the unmatched features that are to be marked as reviewed. Clicking Apply will cause the unmatched features that overlap the region to be checked as reviewed in the Match Status Table. Clicking Undo will undo the last Apply action. Merging the Data After matching is complete, the data is ready to be merged and added to the result map. Click the Merge button ( ) on the Auto Conflate Toolbar to show the Merge dialog. The merge directives are: Figure 39. The Merge dialog. 43

45 Select the conflation type Merge features using Target geometry: Transfer the source attributes to the target data. Use the target geometry for matched features. Merge features using Source geometry: Transfer the source attributes to the target data. Use the source geometry for matched features. Combine Source and Target without Merging: Do not merge matched features, but instead include both source and target features in the result with equivalent geometries. The MM_MATCH_TYPE attribute will be set to either unmatched target or unmatched source. Synchronize: Synchronize source features with their matching target features. Align Source to Target: Move the source features to align with the target data. Use Merge Parameter Layer: Execute a Merge Parameter Layer whereby the features in each of the layer s polygons are merged according to the Merge Parameter Layer polygon s merge parameter attributes and the current attribute mapping table. Choose the features that will be transferred to the result Add unmatched target: Add the target features that do not match any source features to the result map. Add unmatched source: Add the source features that do not match any target features to the result map. These features are referred to as orphans and adding orphans to the result map is referred to as densification. Add matched: Add the features in which a match was found to the result map. Merge snap distance: This parameter is used when adding new source features to a target map. An example is the addition of alley ways from a map that contains only alley ways to a map containing roads with no alleys. Unmatched source features (orphans) that would otherwise not be connected to the target network in the result map will be snapped to the nearest target feature when the orphan s valence one node is within the merge snap distance (in meters) of the target feature. Target line features that have a valence one node within the snap distance of a source feature will also be snapped. Both gaps and overshoots will be removed. This parameter applies only to line feature classes. Specify how attributes are transferred to the result The attribute transfer settings apply to the attribute mapping set in the Attribute Mapping Table. Use Source: Replace the target attribute value with the source attribute value. Use Source unless null or blank: Replace the target attribute value with the source attribute value unless the source has a null or blank value. 44

46 Use Target: Use the target attribute value. Using this setting in conjunction with preferring the Target geometry and adding orphans to the result are settings for densification, where new features from the source are added to the result and no attributes are transferred. This densification setting will cause MapMerger to remove degree 2 pseudonodes that were added during matching from the result map in order to produce a result that is equivalent to the target but with the additional orphan features. Use Target unless null or blank: Replace the target attribute value with the source attribute value if the target has a null or blank value. Node cleanup Additional nodes are introduced at various stages during the conflation process. Many of the added nodes are pseudonodes, valence two nodes that are unnecessary because they split two line features that have identical values for their attributes of interest. It is often desirable to remove pseudonodes from the merged data because they needlessly increase the number of features in the result dataset. MapMerger will introduce nodes that split features during import at Intersections that did not have nodes in the original data, such as overpasses. Bends that are greater than the angle specified in the Add nodes at bends data configuration setting. Locations where the opposite map has a node within the distance specified in the Seed distance data configuration setting. Locations where features that have more vertices than the maximum allowed vertices configuration setting are split. Nodes that turn out to be unnecessary may also be added with the Split Line tool during match editing. MapMerger has three levels of node cleanup: None, Standard and Aggressive. None will instruct MapMerger not to remove any nodes from the merged map. Standard will move all pseudonodes added by MapMerger. These include pseudonodes added during import and pseudonodes added during matching. Aggressive will remove all pseudonodes, even if the node was original to the source or target imported layers. Linear Referencing Transfer M values from Source: Transfer measure values from the source to the target. This selection is only enabled when the source map has measures. In the case where both the target and source have measures, checking this box will cause the source measures to replace the target measures. 45

47 Attribute Mapping Dialog The Attribute Transfer dialog allows you to control how attributes are transferred to the result map. The Attribute Mapping button on the Merge dialog activates this dialog. Not pressing the Attribute Mapping button will cause MapMerger to use a default attribute mapping. Figure 40. The Attribute Transfer dialog. Figure 40 shows an example of an attribute mapping. The source and target attributes are listed at the top of the dialog. Selecting an attribute from the source together with an attribute from the target and pressing the Add button will move the attributes into the attribute mapping table. In this example, the source attribute FENAME is mapped to the target attribute ROADNAME. This means that the target ROADNAME attributes will be replaced with the source FENAME attribute for all matched result features. Attributes that are mapped to will be appended to the result attribute list. The default attribute mapping is used when an attribute mapping is not explicitly defined. When the target layer is either shapefile or file geodatabase, the default attribute mapping is to transfer all source and target attributes to the result map. If the target layer is an SDE geodatabase, the default attribute mapping is to keep all target attributes and not append any new source attributes. 46

48 Source attributes are mapped to target attributes with the same name. Examples of the two types of default attribute mappings are shown below. Figure 40. Default Attribute Transfer dialog example when target layer is not an SDE geodatabase. In figure 40, the default attribute mapping maps source attributes to target attributes with the same name. These attributes are FNODE_, TNODE_, LPOLY_, RPOLY_ and LENGTH. The other source attributes are appended to the result attribute list by mapping them to Not shown because they are at the bottom of the attribute mapping table are the rest of the target attributes which are also mapped to MapMerger will only transfer attributes to attributes of the same type. An exception is that MapMerger transfers attributes of type GUID and GLOBAL_ID by first converting the attribute value into text and then transferring the text value into a text attribute. 47

49 Figure 41. Default Attribute Mapping dialog when the target layer is an SDE geodatabase feature class. Figure 41 shows the default attribute mapping for an SDE target layer that does not include new source attributes. Densification Densifying a map means to add unmatched source features or orphans to the target map. To densify a map, set the conflation type to Merge Features, choose to add all features to the result, and specify to Use Target attributes. These settings will cause MapMerger to produce a result 48

50 map that has identical geometry to the target with additional source features added to the result. All pseudonodes added to the target during matching will be removed. Aligning Line Layers MapMerger will align the source to the target layer by either spatially adjusting the source or by replacing the source geometries with their matching target geometries. A spatial adjustment yields an approximate alignment that is dependent on the quality of the link vectors obtained through point and line matching. Replacing the source geometry with the matching target geometry will yield a precise alignment as long as the matching is done thoroughly and accurately. Choosing to Align source to target in the Merge dialog will disable all other selections in the dialog. Pressing OK will bring up the Alignment Type dialog Figure 42. Alignment Type dialog showing two different types of alignment methods. Data Synchronization Selecting synchronize for the conflation type directs MapMerger to perform data synchronization. After selecting OK in the Merge dialog, the Attribute Mapping Selection dialog is displayed. The attribute mappings that will be examined for possible attribute value differences are chosen from the total list of attribute mappings. 49

51 Figure 43. Attribute Mapping Selection where attribute mappings are chosen that will be examined for possible differences. The Change Detection window is comprised of three main sections (Figure 44: items 1, 2, and 3). The Change Detection Table (item 1) lists matches that have differing attributes or geometry: Attribute difference: At least one of the attributes that were considered for differences had a different value in the Source than in the Target. Geometric difference: Two matched features are separated by more than the Geometry Tolerance. If you change the tolerance, click Refresh in the Change Detection Table for the change to be reflected. Highlighting a row in the Change Detection Table (item 1) will cause the display to pan to and highlight the feature. The differing attributes of the selected feature are shown in the Changed attribute values table (Figure 44, item 2). Below the Change Detection Table are the selections that allow you to resolve the differences (Figure 44, item 3). Source: transfer the Source attributes to the result. Target: transfer the Target attributes to the result. Source unless null or blank (Src/Null) : transfer the Source attributes to the result unless the attribute has a value of null or blank.) Target unless null or blank (Tgt/Null) : transfer the Target attributes to the result unless the attribute has a value of null or blank.) 50

52 Figure 44. Change Detection Window For each attribute difference, review the changed attribute values and the map display. Figure 45 shows a feature with an attribute difference highlighted. Note that selecting a row in the Change Detection Table causes the feature with the differing attributes to be highlighted. Select the appropriate way to resolve each attribute difference. In Figure 44, the Target attributes will be used for the result attribute value, unless the target attribute value is null or blank. 51

53 Figure 45. Attribute difference highlighted. To set the attribute change detection preferences: 1. Select default preferences for resolving attribute differences (Figure 46, item 4). 2. Review differing attribute values and click the Attribute Preference button(s) (item 3) to set the action to take to resolve the attribute difference. Click the Reviewed button (item 3) to keep the default action while marking the difference as having been reviewed. Each time an action is set or the reviewed button is clicked, the date will appear in the Date Modified field. 3. Click the Default Attribute Preference button(s) (item 4) to reset the attribute resolution action to the default setting(s) and remove the date from the Date Modified field. 4. Click the Refresh button (item 5) to reload the Change Detection Table. This is important to do after changes are made to the matching or if the geometry tolerance has been changed. 52

54 Figure 46: Resolving differences: Steps to take After all differences are resolved, merge the layers to generate the MapMerger Result layer. In the Change Detection Table dialog box, click the Merge button (item 6) after selecting actions to perform for each difference. Clicking on a feature with MapMerger s Show Attributes tool will scroll to and highlight the corresponding row in the Change Detection table. Reviewing Merge Results The merged data is previewed through the result MapMerger layer. The merged results should be reviewed prior to writing the result ArcMap layer to ensure good results. Look for slivers in the result preview layer that may indicate unmatched source and target features that should have been manually matched. Use the Alt-S and Alt-T keyboard accelerators to toggle between a MapMerger layer view showing only the result and a view showing the source, target and link vectors. These two views are good for locating a possible problem in the result layer, and then to quickly view the data that produced the observed result (refer to the section Toggling between Two Different MapMerger Layer Views). 53

55 Attribute values should be checked to make sure they were transferred properly (such as address ranges being split in a one-to-many match). The Show Attributes tool in the MapMerger Manual Conflate toolbar is similar to ArcMap s Identify tool except that it operates on data in the MapMerger internal format and shows the value of attributes that were imported into MapMerger. Selecting the Show Attributes tool then clicking on a feature will display the Show Attributes dialog (Figure 47). The attribute values for the feature selected are listed. If features from more than one layer are selected, then the displayed feature s layer is shown at the top of the window. If more than one feature is associated with the selected geometry, then MapMerger will differentiate the feature shown by displaying the layer followed by the number of the feature, such as Source1 and Source2. Finding Topology Breaks Figure 47. The Show Attributes window. MapMerger will automatically identify locations in the merged map that have topological inconsistencies that were likely caused by incorrect matching. A solid cyan circle is drawn wherever an unmatched source feature intersects a matched source feature. 54

56 Figure 48. A topology break symbolized with a colored circle in the merged map. In figure 48, a solid circle is drawn at the location where an unmatched source road intersects a matched source road. The merged map as shown has two roads intersecting that correspond to two roads that did not intersect in the original source map. In this instance, the wrong source road being matched to the target road caused the topology break. The matched line features that are associated with topo breaks will appear in the Match Status Table as matched but checkable features. These items should be reviewed and corrected if necessary before writing out the final conflation results. Unmatched source or orphan features should be examined closely to ensure they are placed in the proper location in the result map. MapMerger calculates a spatial transformation from the link vectors generated during matching. This transformation is used to place orphan feature in a location that can be viewed prior to merging by showing the adjusted source map. The orphan features are colored in the lighter purple color. Adding anchor points (link vectors) that link the orphan features to a specific position on the map will modify their location. The orphan features that connect to a target feature should receive special attention. MapMerger ensures that these features will be connected to the target data without undershoots or overshoots using a pre-determined algorithm. The location of these features may need to be altered. 55

57 Overlaying the vector data on an orthorectified image of the conflation region is helpful in determining the proper position of the unmatched features. Using the Merge Parameter Layer The Merge Parameter Layer is a polygon layer that specifies merge parameters for specific regions. Each polygon feature in a merge parameter feature class has attributes that control the merge for source and target features that overlap that polygon. Figure 49. Attribute table for a Merge Parameter Layer The Merge Parameter Layer s attributes are: Matched: A value of 1 directs MapMerger to include the matched features in the result. UnmchTgt: A value of 1 directs MapMerger to include the unmatched target features in the result. Orphans: A value of 1 directs MapMerger to include the unmatched source features in the result. TgtGeom: A value of 1 directs MapMerger to use the target geometry for matched features. Align: A value of 1 directs MapMerger to align the source geometries to the target geometries. A value of 0 directs MapMerger to transfer attributes between the source and the target using the current attribute mapping table. Replace: A value of 1 directs MapMerger to align by replacing source geometries with their matching target geometries. A value of 0 directs MapMerger to spatially adjust the source into alignment with the target. This parameter is only relevant when the Align parameter has a value of 1. SrcAtts: For attributes that are mapped together in the attribute mapping table, a value of 1 directs MapMerger to replace the target attribute value with the source attribute value when transferring attributes. A value of 0 directs MapMerger to keep the target attribute value. This parameter is only relevant when the Align parameter has a value of 0. TxNull: For attributes that are mapped together in the attribute mapping table, a value of 1 directs MapMerger to replace the attribute value even if the new attribute value is blank or null. A value of 0 directs MapMerger to not transfer null or blank attribute values. This parameter is only relevant when the Align parameter has a value of 0. SnapTol: This sets the Orphan snap distance configuration parameter in units of meters. The Orphan snap distance is used when adding new source features to a target map. Unmatched source features (orphans) that would otherwise not be connected to the target network in the result map will be snapped to the nearest target feature when the feature is within the orphan snap distance (in meters) of the target feature. The parameter only applies to line feature classes. The value of zero directs MapMerger not to snap the orphans. 56

58 RmSrcNds: A value of 1 directs MapMerger to remove nodes where possible from the merged map that were introduced to the Source during import. RmTgtNds: A value of 1 directs MapMerger to remove nodes where possible from the merged map that were introduced to the Target during import. Figure 50. Selecting the merge parameter layer to execute. Choose the merge parameter layer from one of the layers in the table of contents. MapMerger will merge all the features within the layer s polygons according to each polygon s merge parameters and the current attribute mapping table. Creating the Result Layer (non-sde source and target layers) After merge is completed, the ArcMap result feature class is ready to be created. Clicking the Create Result button ( ) on the MapMerger Auto Conflate toolbar will show the Create Result in File Geodatabase window. Figure 51. Creating the result in a file geodatabase. To create the result, enter the path to a file geodatabase that will contain the result feature class and the name of the result ArcMap layer (feature class). The result feature class will be created in the geodatabase specified. If the result destination feature class already exists, MapMerger will ask whether to overwrite or modify the result feature class. 57

59 Figure 52. Overwriting an existing feature class. Modifying an existing feature class requires a clip layer to have been selected, since the clip polygon defines the region that will be modified. Figure 53. Overwriting a portion of an existing feature class. If no clip layer had been used during data import and a clip layer exists in the map, then choosing Yes will prompt MapMerger to show a window that lets a clip layer be chosen from a list of polygon layers that are in the table of contents. Checking Create change detection layer will direct MapMerger to create a Change Detection group layer containing feature classes showing geometry differences, added nodes and, if a synchronization was performed, an attribute difference layer. The attribute difference layer has attribute fields that identify whether mapped attribute values are the same or different for each matched feature. Importing all attributes during MapMerger's import operation data will increase the speed in which the attribute difference layer is created. 58

60 Figure 54. The change detection layers. MapMerger creates the result layer and the Change Detection group layer (if the Create change detection map was checked). The result layer is symbolized according to the feature s match status. The default colors for the result layer are grey for matched, orange for unmatched source and yellow for unmatched target. Within the Change Detection group layer are layers showing changes in attribution, geometry and feature segmentation. For synchronizations, MapMerger will show changes in attribution in a layer with the suffix _attribute_diff. Features with changes in one of their attributes of interest are symbolized in red, otherwise they are colored blue. Geometry changes are shown in a layer with the suffix _geometry_diff. The matched features range in color from green for the closest geometries to red for the most dissimilar geometries. Unmatched features are colored blue for target and violet for source. Segmentation changes are shown in a point layer with the suffix _added_nodes. The points in this layer correspond to locations where features were split by MapMerger to ensure one-to-one matching. Orange points show where source features were split and grey points show where target features were split. The Create removed feature layer check box appears when features have been deleted using MapMerger s Delete Features tool. Checking Create removed feature layer causes MapMerger to create feature classes containing the deleted features for the source and target. A deleted feature layer is automatically given a name of MM_deleted, followed by the tile number (if tiling was done), followed by the source or target layer name, followed by the result layer name. An example of a layer created with removed features in which the source was named tiger is MM_deleted_tile_1_tiger_result. 59

61 Transferring the Z Elevation Coordinate to the Result Feature Class For conflations involving a target feature class with a Z elevation coordinate, MapMerger will ask whether the Z coordinate should be transferred to the result. The Transfer Z From Target window will appear just before MapMerger starts writing the result feature class. Figure 55. Confirming that the Z coordinate will be transferred to the result. If Yes is chosen, MapMerger will transfer the Z coordinate for all vertices that have a corresponding vertex in the original feature class data. Unmatched features that have been spatially adjusted will have their vertices retain their original Z coordinate value. Vertices that have been added during the conflation process will be assigned the default Z coordinate value, which is lowest negative Z value in the map that is less than -440 meters (the elevation of the Dead Sea) and larger than If there are none of these negative Z values in the data, then the default value of will be used. Regardless of the Z values present in the data, the default Z value can be overridden with the transfer_z*null_z_value resource (see the section on using the resource file). Creating the Result Feature Class (SDE source or target feature classes) When the target is a feature class in an SDE geodatabase, MapMerger provides options for creating the result by either modifying the target in a new version of the SDE geodatabase, modifying the target in an existing geodatabase version, or by creating a new feature class in either an SDE or a file geodatabase. The choices available depend on the type of merge operation completed. Figure 56. Choosing how to create the result feature class when the target is a feature class in an SDE geodatabase. 60

62 The first two options will modify the target feature class. If an active region was used to merge a subset of the map extent, then MapMerger will overwrite the target feature class within the merged area, and write the rest of the target unchanged. If a new feature class is written out, MapMerger will write only the area merged within the active region. Choosing to create a new feature class in a file geodatabase will prompt MapMerger to ask for the geodatabase and result feature class names. Transferring attributes to an SDE target layer When transferring attributes to a new version of the SDE target feature class, MapMerger prevents new source attributes from being transferred. Instead, MapMerger provides the option of transferring these new attributes to a separate file geodatabase. Figure 57. Choosing whether to create a new file geodatabase with new attributes. In figure 57 the new source attributes specified in the attribute mapping are listed. Selecting Yes will prompt MapMerger to ask for the result layer and geodatabase names. MapMerger then creates a file geodatabase with the new source attributes in addition to modifying the SDE target layer according to the attribute mapping table. Aligning an SDE source layer to the target layer After completing merge with the option of aligning an SDE source layer to the target layer, MapMerger will ask whether to modify the target SDE layer, or modify the target feature class in an existing geodatabase version, or create the result feature class in a new file geodatabase. Adjusting Other Source Layers Often the source data set contains other layers than the one being matched to the target. For instance, a target data layer consisting of street centerlines might be conflated to a utility base map containing a less accurate road layer and additional layers of facility data. After the road layers are conflated it may be necessary to adjust the other facility layers to be consistent with 61

63 the new target road layer. This is accomplished by clicking the Adjust Layer button ( MapMerger Auto Conflate toolbar. ) in the Figure 58. Selecting layers for adjustment. Add the layers to adjust and enter the file geodatabase that will contain the adjusted feature classes. The adjusted feature classes will be given the prefix mmadjusted. For the example shown above, adjusting the Structure-Travis_Project feature class will yield an adjusted feature class named mmadjusted_structure_travis_project. MapMerger Attributes At merge time, MapMerger adds special attributes to each feature in the result map. The following section explains these new MapMerger attributes. MM_MATCH_TYPE MM_MATCH_TYPE is an integer attribute that indicates the source of a resultant feature. The possible values for this attribute are: 1 = Matched target/source feature. 2 = Unmatched target feature. 62

64 3 = Unmatched source feature. 4 = Matched but unmerged target feature. 5 = Matched but unmerged source feature. If the attribute value is matched but unmerged this means that one of the matched primitives had multiple features, so the features were transferred and not merged. MM_SCOR MM_SCOR is a floating-point attribute that indicates the confidence level of a match. The lower the value, the more confident the match. If the feature was unmatched, this will be some large sentinel value. MM_TARGET_NOTE and MM_SOURCE_NOTE A text attribute that contains a user entered text describing a specific type of match situation. The user edits this value by right clicking with manual line match tool. ObjectID Fields MapMerger creates two integer attributes corresponding to the ObjectID type fields in the source and target data sets. The attributes are named by appending the ObjectID field name to the names source or target for the source and target maps, respectively. For example, if the ObjectID field in the source and target data is named FID then the FID values will be transferred to the result map and stored in attributes named sourcefid and targetfid. Metadata Figure 59. The MapMerger Result Details table. MapMerger creates a table named mm_result_details in the same geodatabase as the result feature class. The table contains the name of the result feature class, and the file paths to the source and target feature classes. Rows are added to the table for each additional conflation result written to the geodatabase. This table is particularly useful in keeping track of interim results created during a multisource conflation. Viewing the MapMerger Log MapMerger logs all conflation operations to the MapMerger log file. Every message that is written to the ArcMap status window is also written to the MapMerger log file. The log file has the same name as the ArcMap.mxd map file except the.mxd extension is replaced with.log. The MapMerger log can be viewed anytime by clicking the Show Log button ( ) on the Auto Conflate Toolbar. Right clicking the mouse over the interior of the log window will display a pop-up menu with menu items Save As, Clear and Copy. Save As enables the log file contents to 63

65 be saved to a text file, Clear will erase the contents of the log window and Copy will copy the contents of the log file to the clipboard so that it can be pasted into another text window. Figure 60. The MapMerger Log window with pop-up menu. Conflating Polygon Layers MapMerger has the ability to align a polygon layer to a more accurate polygon or polyline layer and to transfer attributes between polygon layer features. For example, a boundary layer representing timber stands can be aligned to a road layer. The boundaries can be either adjusted or portions of the boundaries can be replaced with road geometries that align with the timber stand borders. Importing Polygon Data Polygon feature classes are converted into line features for processing by MapMerger. The original polygon attributes are transferred to the line features and are given a _left or _right suffix denoting that the attribute applies to the left or right polygon. The attributes are then available to assist with automatic point and line matching. Importing source and target polygon feature classes will cause MapMerger to bring up the Polygon Conflation Type dialog. Figure 61. Choosing the polygon conflation type. Select Polygon Alignment if the source will be aligned to the target or select Attribute Transfer if attributes will be transferred from source to target. 64

66 Polygon Alignment After point and line matching are completed, click the Merge button to choose the type of polygon alignment. Figure 62. Choosing the type of polygon alignment. Replace source boundaries with matching target boundaries directs MapMerger to create a result map consisting of matched and unmatched source features in which the matched features have the target geometry. The unmatched source features are placed in their spatially adjusted location. The lock down orphan tool can be used to prevent the unmatched source features from being moved. Adjust source to align with target directs MapMerger to create a result map consisting of the spatially adjusted source features. Creating the Aligned Polygon Layer After the polygons are aligned, the result polygon layer is ready to be created. Clicking the Create Result Layer button ( ) on the MapMerger Auto Conflate toolbar will show the Create Result dialog if the source is an SDE geodatabase or the Create Result in File geodatabase dialog if otherwise. For non-sde source layers, enter the name of the result ArcMap layer and the path to the file geodatabase that will contain the result layer. The result feature class will be created in the geodatabase specified. Figure 63. Creating the result polygon layer. 65

67 MapMerger converts the result polygon boundary lines into polygon features through a multistep process. Polygon Attribute Transfer To transfer attributes between polygon layers, first import the source and target polygon layers into MapMerger. MapMerger converts the polygon features into line features that correspond to the polygon boundaries. Matching then proceeds as in matching line layers. MapMerger will consider two polygon features as matched when all of their boundary lines are matched together. If any of the polygon boundaries are unmatched or are matched to a different polygon, then the polygons are considered to be unmatched. Upon completing line matching, click the Merge button and select to Transfer attributes to Target in the Merge dialog box. MapMerger will transfer attributes to target features as specified by the Attribute Transfer options. Unmatched source features will not be added to the result. The merged result consists of the target layer geometry with source attributes transferred to their matching target features. Creating the Result Attributed Polygon Feature Class After merge is completed, the result polygon feature class is created in the same manner as result line feature classes. For SDE target geodatabases, MapMerger will query whether to modify the SDE version or create a new file geodatabase. If modifying the SDE version is selected then MapMerger will ask whether to add new source attributes to a feature class in a file geodatabase. MapMerger will then create the result by modifying the target feature class in a new version of the target geodatabase. Rapid Change Detection The Rapid Change Detection tool ( )streamlines the process of comparing two versions of a feature class to determine changes in geometry and attribution. Upon activating the tool, MapMerger will show the Automatic Matching window. Figure 64. Automatic matching for rapid change detection. Enter a value for the search distance and click OK. MapMerger will match the data by first performing point matching followed by line matching. After matching is complete, the Attribute Mapping Selection window is displayed. 66

68 Figure 65. Selecting the attribute mappings that will be reviewed for differences during rapid change detection. The attribute mappings that will be examined for differences are selected from the list of attribute mappings. MapMerger compares the attribute values for matched features in preparation for creating the attribute difference layer. If no attribute mappings are selected then MapMerger will skip attribute change detection and will instead only perform geometry change detection. Figure 66. Creating the change detection map. In the Create Change Detection Map window, enter the name for the result layer and file geodatabase. A Change Detection group layer will be created that contains feature classes that show changes in geometry and attribution (if an attribute mapping was selected for change detection). The attribute difference feature layer is symbolized to prominently display by color, features that have had an attribute of interest change value. Note that importing all attributes during MapMerger's import operation data will increase the speed in which the attribute difference layer is created. 67

69 Figure 67. The rapid change detection difference map layer. In Figure 67, the attribute difference layer for two versions of a road layer is overlaid on imagery. The features that have had their road surface type change are rendered in red. In this example, the attribute difference map clearly shows that some bridge surfaces have been modified. Saving Match Information Node matches, line matches and anchor points can be saved to a text file by clicking the Save Match Information button ( ) on the Auto Conflate Toolbar. Saving match information should be done frequently during node and line matching. MapMerger can later import the match information and generate the saved node matches, line matches and anchor points pairs. 68

70 Figure 68. The Save Match Information dialog. Enter the filename with or without a.mch filename extent. MapMerger will append the filename with the.mch extension. 69

71 The format of the match information file contents is shown below. Point Matches source target ID x y x y Auto Anchor Point Match Line Match Vertices source target FID x y x y x y FID x y x y x y Auto AttTx Date GeomTx Date Preferring source attributes Preferring target geometry Don't Match and Delete Points Target Annotation Attributes Default Attribute Transfer Setting Default Geometry Transfer Setting Match Reviewed Status map x y value The point matches are listed first followed by the line matches. The first column in the point match section is the anchor point pair ID. Each anchor point pair is assigned a unique ID that is saved with a MapMerger project. The next four numbers are the coordinates of the source anchor point followed by the target anchor point coordinates. The last three columns describe the type of point match. Their values are described in the following table. Auto Generated through automatic point or line matching. Y N Generated through manual point or line matching or through anchor point import. Anchor Point The point match is an anchor point pair. The point match is not an anchor point pair. Match The point match is a node match. The point match is not a node match. The source and target lines in a line match are each represented with three points that describe the line. The first and third points are the end points of the line. The second point is a point on the line that is closer to the From node. The last columns in the line match section have a value of Y if the line match was generated automatically or a value of N if the line match was generated manually and a value of either source or target specifying where the attribute and 70

72 geometry information will be transferred from. Each line definition is preceded with the line feature ArcMap FID number. The point and line matches are followed by the midpoints of the deleted line features. The annotated feature midpoints along with their text annotation are listed next. This is followed by the default attribute transfer and preferred geometry settings from the last completed merge operation. The final entries list the midpoints of the features that are checked in the match status table. MapMerger also writes the point match coordinates to an ArcMap link file that can be used in the ArcMap spatial adjustment tool. The link file will have the same name as the match information file except that the.mch extension will be replaced with.link. Importing Match Information Node matches, line matches and anchor point information can be generated in MapMerger by importing match information from a match information file. Click the Import Match Information button ( ) on the Auto Conflate Toolbar to specify the match information file to import. Figure 69. The Import Match Information dialog. MapMerger will attempt to generate the node matches, line matches and anchor points contained in the match information file using the same rules that apply when node and line matches are made manually. The MapMerger log file documents any problems that occur during the import of match information. 1. To add a new node match, both points in the node match must lay on either an unmatched source or target line feature. MapMerger will split the line feature and add a node if no node is found at the specified location. 2. To add an anchor point pair, the source point in the pair must lie on a source line feature. 71

73 3. To replace an anchor point, the new anchor point ID must be the same as the ID of the anchor point ID it is to replace. If the anchor point that is to be replaced is also part of a node match, then the anchor point portion of the node match will be replaced. The node match will not be removed and will appear as a blue link in the MapMerger node match display because it is a node match that is not an anchor point. 4. To add a line match, the points specifying the line must lie on an unmatched source or target line feature. Importing Anchor Point Information Clicking the Import Anchor Points button ( ) on the Auto Conflate Toolbar and selecting a match information file will import the anchor points from the file. Figure 70. The Import Anchor Point and Line Match Information dialog. All point matches in the match information file, regardless of whether they are specified as a point match or not, will be generated in MapMerger as pure anchor points that do not have an associated point match. MapMerger relaxes the rules it applies to adding anchor points in this case. The anchor points do not need to lie on an existing line feature. Anchor points with the same ID as the anchor points being added will not be replaced, but will be added with a new ID. 72

74 Advanced MapMerger Configuration Settings that control various details of MapMerger operation are accessible through the Configure button ( ) located on the Auto Conflate Toolbar. Point and Line Match Settings Manual point and line match configuration parameters are shown in figure 71. Manual point match settings Figure 71. Settings that control point and line matching. Shift click to add pure link vectors. A pure link vector is an anchor point pair that is not a point match. By default, this setting is checked causing the operator to hold the shift key down during manual point matching to create a pure link vector. Unchecking this setting will reverse the 73

75 default operation and cause MapMerger to add pure link vectors without the shift key being held down. Holding the shift key down will cause MapMerger to add point matches. Include point matches in spatial transformation. Manual point matches are included in the spatial transformation by default. When this setting is not checked MapMerger will not include manual point matches in the spatial transformation. Manual line match settings Include point matches made during line matching in spatial transformation. By default, node matches created during manual line matching are included in the spatial transformation. If this setting is not checked, MapMerger will not include the point matches generated during line matching in the spatial transformation. Include point matches made during multiline matching in spatial transformation. By default, node matches created during manual multiline matching are included in the spatial transformation. If this setting is not checked, MapMerger will not include the point matches generated during multiline matching in the spatial transformation. Do node matching during multiline matching. By default, MapMerger creates point matches during multiline matching by adding nodes where needed to ensure that each node has a nearby matching node in the other multiline. The nodes are added at a similar proportional distance along each multiline. When this setting is turned on, MapMerger will only add nodes if a match cannot be made to a node found within a search distance in the other multiline. Excluding Features Exclude features overlapping selection rectangle. This setting controls how the Exclude Feature tool marks features for exclusion. If this setting is checked, the features that overlap the selection rectangle will be marked for exclusion. If this setting is not checked, only features that lie entirely within the selection rectangle will be marked. Click Range Click range. The distance in pixels that is used by the match editing tools to determine how close a mouse click must be to an object such as a line or point in order to select the object. 74

76 Data Settings Settings that control how MapMerger imports data are shown in figure 72. Figure 72. Advanced data import configuration settings. MapMerger's advanced data import settings provides the following capabilities: Remove target pseudonodes. Remove nodes from the target feature class that separate two features with identical attribute values. This setting defaults to off. Remove source pseudonodes. Remove nodes from the source feature class that separate two features with identical attribute values. This setting defaults to off. Target snap distance. Close gaps and remove overshoots (also known as dangles) in the target data that are less than the target snap distance. The locations of the gaps and dangles that are removed are listed in the log file. 75

77 Source snap distance. Close gaps and remove overshoots (also known as dangles) in the source data that are less than the source snap distance. Maximum vertices per line feature. This parameter will limit the number of vertices per line feature. The default is 400. Maximum bend angle. When Add nodes at bends is checked, this parameter will cause MapMerger to split line features where they bend more than the maximum bend angle. Seed distance. This parameter is used when the two maps being conflated have line features that would otherwise match if not for the existence of pseudonodes. Setting this parameter to a non-zero distance (in meters) will cause MapMerger to insert nodes during data import wherever there is a node within this distance in the other map. This will improve the results of node matching and consequently line match results should improve as well. Closest allowed node. Node seeding will not occur if there is an existing node within the distance specified by this parameter (in meters). Seed nodes in source. Check this to enable source node seeding. Seed nodes in source. Check this to enable target node seeding. Geometric tolerance. Map elements must be separated by a distance greater than the geometric tolerance in order for them to be considered separate entities. By default, MapMerger calculates the geometric tolerance during data import. Explicitly setting the geometric tolerance will override the automatic calculation. True arc sample interval. True arcs are feature geometries that are described by a mathematical formula rather than a series of vertices. MapMerger creates vertices to store true arcs by sampling true arcs at this interval. Smaller intervals result in higher accuracy but at the expense of increased memory usage. The interval is in units of meters. Clicking the restore default button will return the dialog to the default state. 76

78 Spatial Adjustment Settings Settings that control how the spatial transformation operates are shown in figure 73. Figure 73. Settings that control the spatial transformation. Attenuation factor. MapMerger's spatial transformation is an inverse-distance weighted-average of nearby displacement vectors defined by the neighboring link vectors. By default, the influence of each link vector on a point s displacement attenuates by the cube of the distance from the point to the link vector. Setting this attenuation factor parameter will override the default parameter. Max link vector influence distance (meters). Link vectors that are beyond this distance from a point will not influence the point s displacement. 77