Overview. Review. GEOL 452/552 - GIS for Geoscientists I. Lecture 4. what is a feature class? What is georeferenced Data? what are layers?

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1 GEOL 452/552 - GIS for Geoscientists I Lecture 4 Overview Tutorial and HW 1 went OK? Today Review of concepts from last lecture Scales Labels ArcMap follow-along tour More material about ArcMap in WebCT 9 Using_ArcMap_1.pdf (supplemental from textbook) Lab: ch 2 tutorial 1-32, HW2: ch 2, ex. 1,2,3 and 5 Next lecture: displaying numeric data maps + rasters Review What is georeferenced Data? what is vector data? georeferenced data what is a feature? Data kept in a table data with a direction a single piece of vector data Geologic Data Data at a location on earth points, vertices, nodes georeferenced points, lines, polygons vector data with more than 3 points 1 what is a feature class? features sharing the same theme (e.g., all city related data) what are layers? a feature class what are records? Collection of feature with the same geometry set of attributes for a single feature Collection of features with same geometry and the same attribute table a collection of vector or raster data within a shared geographic area both are true a row within an attribute table 2 3 4

2 When opening a mxd file, a red! besides a layer means: This layer is very important (!) This layer s data has not yet been symbolized (colored) by a user Call tech support, ( ), you ll never fix this one! This layer s data file is not where it should be and needs a re-connection Review What best describes a ArcGIS map document? Like a Microsoft Word (.doc) document Digital version of a printed paper map Collection of data references and their appearance Collection of data layers including their appearance 5 6 Map scale concepts What does a map scale of 1:1000 mean? 1 length unit (inch) on the map is 1000 length units in reality (also inches!) May need to convert: inches to miles (or km!) What s a large scale map? Is 1:1000 larger than 1:5000? (what does zoom in mean?) compare the ratio (1 divided by xxxx) not the scale number 1:1000 is of larger scale then 1:5000 Tip: in ArcMap, you can type (for 1:20,000) as Map scale Large scale maps - very zoomed in - small physical area (ex. city) Small scale maps - very zoomed out - large physical area (ex. whole globe) How to get physical size of a feature (lake) that is 2.5 cm wide on a 1:100,000 map? A) paper map: solve equation B) ArcMap: Use Measurement tool 7 8

3 The Length of a 100 yard football field measures 0.5 inches on a map - what is the map s scale? Real world length of 100 yards in inches is 100 yards * 36 in/yd = 3600 inches (see last page of text book for unit conversions) Set up the ratio - what is x in: 1 / x = 0.5 / 3600 x / 1 = 3600 / 0.5 x = 7200 The map s scale is 1: inches on map 100 yards 1 inch on map = 7,200 inches in reality 1 0.5? 3600 No reference scale set: zoom in - labels are still small Reference scale Reference scale sets the size of features relative to a specific scale. When set, symbols change size after zoom Dataframe-wide property 9 10 Scale Range 1:325,582 Simple Labels (user-placed) How does a scale range of 1:300,000 work? Map scale number of 325,582 is greater than display scale range number of 300,000 - layer is invisible 1:260,425 Here s a trick - for scale range, think in scale numbers (the number after the 1: ) Map scale number of 260,425 is smaller than display scale range number of 300,000 - layer is visible (Attribute) (Attribute) No attribute: greyed out 11 12

4 Dynamic ( Smart ) Labels Placed automatically for an entire layer Redrawn when map view changes: pan, zoom, etc. Autoplacement (no label overlap) Placement priorities (preferred place Conflict resolution (with other labels and features) Auto placement can be slow on maps with many features Other options: Labeling classes ( all large towns are... ) Scripts ( %NAME: %POP people ) Alternative (better) labeling engine: Dataframe - General - Label engine - Maplex Annotations Think: static ( frozen ) labels for nicer maps Dynamic labels that have been converted to static text You can adjust their size, place, orientation You cannot go back to dynamic labels Best: create annotation after you re sure you have a (mostly) good solution from dynamic labeling 13 Arc Map Follow-along tour Open ex2mapdoc.msx in your student folder (mgisdata\mapdocuments) Save As ex2mapdoc_in_class.mxd now (so you don t overwrite the official version) Much more to poke around - see Using_ArcMap_1.pdf

5 Table of Contents (TOC) Menu bar Map scale Toolbars View Modes Map window in Layout View Refresh Data view Layout view Data frames Active frame Type of View Mode (now: layout) Map units display Different navigation task bar Data Frames Concept: virtual map, many layers think data frame = mini-data mode window Data frame can only be seen in layout mode Active data frame: right-click on data frame - Activate or: click on frame in Layout mode Don t confuse data frame properties with layer properties, or with groups of layers Data frame properties 2 x click to open Data frame Units in which the map is displayed 19 20

6 The table of contents Drag layers in data frame Change draw order Different units in ArcMap: Scale bar shows current scale as you zoom in/out Access layer properties (2x click) Turn layers on/off Set display units in layer properties (map units are internally set) Position bar shows current location of cursor Change symbol properties Draw Order Display units Page units Identifying features Finding features

7 Measuring Choose units Grouping layers Snap Measure lengths and areas Get exact value 2-39 for a feature shift-click to select multiple layers, then right click and chose group You can change some Display properties (e.g. transparency) for all group layers After creation: change name of group from New Group to <Makes Sense> (press F2) Add data from a map server directly to ArcMap (new in ArcGIS 9.3?) Web browser Save.lyr file, open/add to ArcMap After the break Check out Using_ArcMap_1.pdf for more on labels, symbolizing, styles (WebCT home) Lab: ch 2 tut 1-32 save your progress at the end ch2_tut_step32.mxd HW 3: ch 2 ex. 1,2,3 and 5 (12 pts total) Anybody (really) needs ArcGIS Student versions? ArcView functions + add-on modules (1 year) vpn.iastate.edu to connect to Delphi from home: run VPN client (web/java), then map Z: drive to Delphi 27 28