Importing GPS points and Hyperlinking images.

Transcription

1 Geol 3050 GIS for Geologists Exercise 15 Exercise 15 Making a Virtual Fieldtrip: Importing GPS points and Hyperlinking images. Due: Thursday, March 22. Goal: A) Get familiar with importing GPS points and adding the points to a map. B) Get familiar with hyperlinking images to points or other features in ArcMap. C) Add your stike and dip measurements. Datasets: - your field trip pictures - GPS points from your own GPS - Your georeferenced geologic map from Exercise 13 The data can be downloaded from Assignment: Check the 1967 Eldorado Springs map with the GPS points taken in the field. Do the points match our map? We can document Thursday's field-trip with our field observations (photos) and field descriptions. The steps broken down (more detail follows!) 1. Creating shapefiles from an Excel table: A. Create a table from your points (from Excel as a comma separated *.csv file) B Add the table to ArcMap as an XY Event Layer C. Convert this layer to a shapefile 2. Give meaning to the GPS points: description and hyperlinks: D. Add 2 new fields: one for a description, one for the hyperlink. E. Fill the fields. F. Activate the hyperlinks. 3. Specialized symbology: strike and dip (this would also work for fault offset): G. Create a new point file H. Add strike and dip values to the table. I. Create new symbology

2 GEOL GIS for Geologists Exercise 15 Part I: Downloading your data from the GPS unit. 1) Normally, we could use the GPS tools in ArcMap or 3 rd party software such as BootCamp to download and display our data. But these computers recognize the GPS units as Malware and refuse to connect to them. 2) Since we don t have a lot of points, we ll just create an Excel table and import that to ArcMap. This is a useful skill; any data you find in a non-gis format that has coordinates can be converted into a GIS format! For instance, perhaps you download a table of stream gauge locations or borehole data and want to plot them on a map. 3) Open Excel and label the top row as I did below. Then add the labels, and x and y coordinates from your GPS unit. (Go to the Menu and then Find>Waypoints. Then hit the top right button to access the list. Go through each one and type the coordinates into the Excel table.) 4) Save your excel sheet as GPS.csv, which is a comma delimited or CSV file (file>save as>save as type>csv/comma delimited) You can now close Excel (and ignore the warnings). 5) Open your completed NCAR map from Exercise 15 in ArcMap that has the Wells geologic map and Lidar DEM and hillshade. 6) Click Add Data and select your GPS.csv file.

3 GEOL GIS for Geologists Exercise 15 7) Right Click on the Table and select Display X Y Data. Use x for X field and y for Y field. Select the coordinate system: Projected>UTM>NAD27>Zone 13N (See the image below) 8) Click OK on the warning. Now your GPS points will appear on your map (the points may be small). You should also see GPS.csv Events in your table of contents.

4 GEOL GIS for Geologists Exercise 15 9) ArcGIS is displaying the table data, but it is not editable. For that you will have to Right Click on the layer>data>data Export and then create a shapefile called GPS.shp. When prompted, add this file to your map. You can now remove the csv file from your map. 10) Right click on the GPS shapefile layer and hit Label Points. Note, you can change Label Properties (font size, placement, etc) under Labels tab in the layer s Properties.

5 Geol 3050 GIS for Geologists Exercise Give meaning to the GPS points: description and hyperlinks: The GPS points in the map will lose their meaning pretty fast if you don t annotate them with your notes, and or hyperlink them to the pictures you took. Imagine looking at this data in a year, or handing it over to somebody else who was not even on the trip. D. Assessing your data 37. Zoom in on the points you collected at the first stop. Open the measure tool. 38. Question to turn in: What is the maximum spread (position error) in meters between these points? E. Add 2 new fields: one for a description, one for the hyperlink. 39. Open the table and choose Options > Add Field 40. Add a text field of 150 characters (length) and call it DESCRIPT 41. Add another text field of 150 characters and call it Hyperlink. 42. Access the pictures you took and place them on your flashdrive or D:Scratch. 43. Remember the location of the pictures, as you will have to type it in the Hyperlink field (see next few steps): The location of each of the pictures can be found by looking at the address bar in Windows Explorer! F. Fill the fields. 44. Start Editing

6 Geol 3050 GIS for Geologists Exercise Select your point so it shows up light blue! 46. Open the table and find the selected record: a. For hyperlink: type/copy the location (pathname) of your image file (full name including *.jpg!) b. For description: type a sentence describing the GPS point, i.e stop 1 overview, or top of the Fort Hays, etc! If you want to add 2 photos for 1 spot, you can copy and paste the waypoint you want to duplicate (can be done within the table). Check the coordinates and update your hyperlink information to the correct image number. (Pasting can be done by Ctrl+V) 47. Once done editing, save your edits and Stop Editing. G. Activate the hyperlinks. Activating the hyperlinks can be done via the layer properties: 48. Right-click the GPS-points layer in the table of contents. 49. Select from the properties the Display TAB: 50. Select the Hyperlink field and check the hyperlink textbox. 51. Click OK once done

7 Geol 3050 GIS for Geologists Exercise Note that the hyperlink tool on the toolbar is now activated: 53. Notice the blue dots that are activated on the GPS points on the map 54. With the hyperlink tool activated, click on the dots. When you see your pathname light up in yellow, click the dot. Finding the exact spot is actually really hard, so be patient, and try different Zoom levels. 55. Another program that can view.jpg images will now open. Note that you can use this method to view any kind of document. Also web pages are possible. This is an easy way to catalog documents (pdf s for example) spatially. Make a screendump to turn in with the correct record activated in the table, your much smaller picture and your GPS point in the map. It should look like this: - 8 -

8 Geol 3050 GIS for Geologists Exercise Specialized symbology: strike and dip (this would also work for fault offset symbols): H. Create a new point shapefile. 56. Open ArcCatalog. 57. Browse your Exercise 15 folder. 58. Right-click on the folder and choose New > Shapefile. 59. Name it StrikeDip ( or another name could be Bedding). 60. Set the Feature Type to Point. 61. Add 2 additional fields to the attribute table: - Strike (Long Integer) - Dip (Long Integer) 62. Set the correct projection for your new shapefile so that it matches the map and the GPS points. I. Add strike and dip values to the table, in ArcMap. 63. Add your StrikeDip shapefile to ArcMap 64. We will fill the table with the strike and dip values we took out in the field. 65. Manually add the 2 locations we collected Strike and dips for on Thursday. Remember they were in between the top and the bottom of the Ft Hays Limestone and just east of the top of the Dakota. Use your GPS points to position the point: 66. You will have to Start Editing on the Editor Toolbar: 67. Make sure you are editing the correct Target layer! 68. Add your point to the correct locations 69. Convert the measurements for strike to values between 000 and 360 and enter the value in the Attribute Editor (at the end of the Editor Toolbar!), then add the dip measurements to the appropriate field. 70. Stop Editing and save your edits. J. Create new symbology. 71. Go to your StrikeDip- Layer Properties, then the Symbology TAB. 72. First Double Click on the (Single)-symbol. 73. Click on Style References (near the bottom of the dialog box) and 74. Add the Geology 24K Symbology by checking the box: - 9 -

9 Geol 3050 GIS for Geologists Exercise Scroll down the list of symbols and add Inclined bedding showing strike and direction of dip Make Symbol Size Choose OK. 77. Under the Symbology TAB, choose Advanced > Rotation

10 Geol 3050 GIS for Geologists Exercise Set the Rotation Style to Geographic as that will match our measurements. Use Strike as the rotation field! 79. Go to Properties > Labels Tab and Activate Labeling by checking the checkbox. 80. Choose as Label field the Dip. 81. Your symbol is now ready and labeled with the dip! What you need to hand in - One document containing the following: - Nice looking map layout with legend for the GPS datapoints and strike and dip symbol, north arrow, UTM grid, scale bar, on the field map with labeled GPS points (printed from ArcMap). This map is slightly different from our field map as it will have GPS and strike and dip plus their labels and a legend. You don t have to generate a legend for the geology, since that would be easier in Photoshop for example (the map is in raster format, so it cannot be generated automatically by ArcGIS). Make sure the strike and dip symbols are turned on and are visible! - Answers to the following questions: - Question 38: what is the maximum distance of your 5 GPS points taken? - Step 55: Screendump of your full screen in hyperlink mode, with the picture minimized, but visible on the screen (see example) - Compare your field GPS points with the actual geologic boundaries on the map. Are there differences? List at least 3 different types of inaccuracies that can cause differences. Measure with the measure tool how far your GPS points are actually off from the originally mapped boundary, if they are at all. Comment if this is a problem or within the range of mapping error