8.1 Objectives

The primary goal of our field trip this weekend is to locate, as accurately as possible, the main trace of the Mt. Bonnell Fault where it transects the Barton Creek Wilderness Preserve.  Published geologic maps, which you will have with you in digital form, indicate three different locations for the fault.  Your job will be to determine which, if any  is correct.  You will document your findings with geo-located digital photographs and field observations, as well as your own well-located fault trace (or traces).  Lecture handouts distributed this week provide background on the Cretaceous carbonate stratigraphy affected by faulting and outline how we will accomplish our goal.

Because of dense vegetation, one of the principle challenges will be staying located.  The mapping-grade GPS receivers you will use will be invaluable in this regard, but you will also need a gridded, color, geologic map on paper as a backup.  You will prepare such a map as part of this exercise.  We will also need a few empty point and line files to store observations - these you will create as well.  Once these tasks are complete the GIS data will be transferred to the GPS units.  A second section of the lab (Part B), to be done during class Thursday, briefly describes the ArcPad software we will use for data gathering and a practice data collection exercise to be completed before heading out this weekend.

8.2 Data Sources

All field trip vector data are in a geodatabase in the Lab_8_data folder.  A hill shade and elevation raster are stored separately in the same folder, as is a map document.  The data are from the following sources:

1) Geologic map data and layers:

a) Geologic Quadrangle Map (1:24,000) No. 38 - Austin West, Travis County, TX by Rodda, Garner and Dawe, Bureau of Economic Geology, UT Austin, 1970.  Data from this source contains "AustinW_" as part of the file names.

b) The Geologic Atlas of Texas Austin Sheet, 1:250,000, Bureau of Economic Geology, 1974.  The file, "GAT_faults" is from this source.

c) Geologic map of the Edwards aquifer recharge zone, southcentral Texas: U.S. Geological Survey Scientific Investigations Map 2873, scale 1:200,000 compiled by Blome, C.D., Faith, J.R., Pedraza, D.E., Ozuna, G.B., Cole, J.C., Clark, A.K., Small, T.A., and Morris, R.R., 2005.  Data from this source have file names that begin with "EA_".

2) Roads and Park boundaries: City of Austin GIS data

3) Airborn LiDAR elevation data - TNRIS and the Capital Area Council of Governments.  These bare-earth point datas, in .las format, were used to construct a high resolution TIN that was then converted to a 1.8 m-resolution DEM raster ("bc_elev").  The hill shade of this raster is "bc_hshade".

4) A vector stream file ("BCWP_streams") was created by digitizing, using the hill shade raster as a guide.

5) Trail data within the Barton Creek Wilderness Preserve ("BCWP_trails") were collected by Dr. R. Marrett with his cell phone while hiking, as were data points where interesting geologic observations can be made ("Marrett_pts").

The spatial reference for all data is UTM zone 14N, NAD83.  A single spatial reference for all data is required for later use with ArcPad - it is not capable of on-the-fly projection.

8.3 Modifying the Geodatabase for Field Work

1. Download the Lab_8_data folder to your personal storage space.
    
2. Open "BartonCr_327G_project.mxd" and examine the files in the table of contents.
    
3. Using ArcCatalog locate the geodatabase "BartonCr_Field_Trip_data" and create within it two feature classes, one for points called "XX_Points" (substitute your initials for XX) and another for lines called "XX_lines" again substituting your intials for XX.  Specify the coordinate system for both as UTM zone 14N, NAD83 and accept the default XY tollerance.
    
4. Create two new fields in the point feature class, one called "Type" (to specify the type of data collected at the point) and another called "Notes".  Specify both as Text fields with a Lengths of 25 characters.  Create a third field called "Unit" with Data Type = text and a Length of 7 characters.  This field will store rock unit abbreviations.
   
   
5. Do the same for the XX_lines feature class.
   
   
6. Create a Domain (by right-clicking on the BC_Field_Trip_data geodatabase icon, then Properties...) called PT_TYPE, (Field Type is Text) that is a coded-value domain containing the coded values of "photo", "observation", and "other" (see Lab 4) and then attach this domain to the XX-Points attribute field TYPE (again see Lab 4).
   
7. As above, create a coded-value Domain call "LN_Type", (Field Type is Text) with coded values of "fault", "contact", "axial_trace acline" and "axial_trace_scline" and attach this domain to the "XX_Lines" attribute field "Type".
   
8. As above, create a coded value Domain called "Unit_Abbr" (Field Type is Text) with coded values of Kgr2, Kgr3, Kgr4, Kgr5, Ked1, Ked2, Ked3, Ked4, Kgt and unknown.  Attach this domain to the "XX_Lines and XX_Points attribute field "Unit".

Congratulations, you have now completed the modifications to the database you will need for this project.

8.4 Making Field Maps, preparing for export to ArcPad

1. In the interest of time, a 1:10,000 scale field map has been prepared for you and is ready to print.  If not already open, open the "BartonCr_327G_project.mxd", go to Data View (if not already there), and use the "10K field map" Bookmark (a menu item at the top of screen) to get the appropriate map area on the page.
   
2. Print the map in color and don't forget to bring it with you this weekend.
   
   
3. Bring your newly created line_XX and point_XX Feature Classes into the map and move them to the top of the Table of Contents.
   
   

8.5 Trimble Nomad and ArcPad v. 10

GPS data collection using the Trimble Nomad units is done with ArcPad software.  ArcPad is a streamlined version of ArcGIS that is equipped with very easy to use GPS capture tools.  ArcPad 10 is installed on the classroom computers and our field data collection units.  Version 10 is a major revision from earlier releases.  Before getting a little ArcPad practice, we first need to convert the ArcGIS map document file into an "ArcPad Project".  An automated tool exists to do so, which converts most rasters to jpeg images, the geodatabase to an ArcPad exchange format database (.AXF), and makes data entry forms from the domains for each Feature Class.  We can "check out" the empty Feature Classes for editing then, upon return, "check in" the same, permitting the software to automatically update the geodatabase!

An important note for future reference about ArcPad versions:

• ArcPad 10 represents a significant departure from earlier versions (i.e. 8.x and below).  "ArcPad Projects" created for ArcPad 10 will not run on 6.x software, and vice-versa.  The ArcMap toolbar for creating ArcPad projects in versions of ArcGIS 9.1 and higher contains separate tools for creating ArcPad 8.x and 6.x (or lower) projects.  It is thus important to know which version of ArcPad is installed on your field data collection units.  Our Trimble Nomads and Xplore tablet PCs are currently running ArcPad 10, as are the computers in the lab. 

A. Preparing the Map Document for ArcPad (version 10).

1. Open your map document.
    
2. Switch to Data View mode (if you're in Layout mode) and zoom to the "Area_outline" layer.  This is an important step!
    
3. Make sure the "Point_XX", "Line_XX" Feature Classes are present in the Table of Contents of the map.  These are empty, but have coded-value domains already built that will allow use of ArcPad data entry forms.  These are the files you will populate with GPS measurements.
    
4. Change the symbology of these files to colors/symbols that will be recognizable on both a white background and the geologic map.  Red works well, as does light blue.  Remove the outline from the point symbol and make it a little bigger, e.g. size 6.  his is much easier to do now than later in ArcPad.
    
5. If not already on. Turn on the ArcPad Data Manager toolbar (Customize>Toolbars...) shown below.
    

6. On the ArcPad toolbar, click the "Get Data for ArcPad" button.
    

7. Click the black arrowhead to the left of your "Line_XX" layer and choose "Checkout for disconnected editing in ArcPad>data based on defined extent".  Do the same for the Point_XX layer.
    
8. For all other vector layers choose "Export as Background data (to shapefile)>Make Read Only"
9. Do not export any of the raster files EXCEPT "bc_hshade" which should be exported as a Background JPG2000.
10. Click Next.

12. The next window, "Select Picture Options", is not applicable to this project; Click Next.
    
13. The final window lets you set the spatial extent (current display extent or full extent of the layers), lets you select whether to limit the fields to those that are visible in the attribute tables and the features to those specified in the layer's definition query, lets you specify a name for the folder that will store the data, and lets you create an ArcPad map file (the equivalent of an .mxd file) for the data, as shown in the "Get Data For ArcPad" screen capture below.
     
14. Enter a name for the folder, e.g. "ArcPad_BC_XX" (where XX are your initials) and a Map Name that includes your last name or initials (e.g. BC_map_XX).
     
15. Making sure first that your display shows the entire area of interest (i.e. you are zoomed to the "Area_outline" layer), make the selections shown in the figure below, setting the "Where do you want the folder to be stored?" to an appropriate location on your network storage space.

16. Click Next, the Finish, and wait for the data to be created.
     
17. With my help , transfer your new "ArcPad_BC_XX" folder to your Trimble Nomad (these will be shared, but each partner can load a project). The Nomad units have a folder called "My Documents" that should be used for all ArcPad data and files.
    
    
18. Print a color copy of the PDF file "ArcPad Quick Reference", in color, from All Programs>ArcGIS>ArcPad 10>Help>ArcPad Quick Reference.  You will find this exceptionally useful for Part B of this lab, and for the field trip.

Part B: Practice with ArcPad in the field

8B.1 Using ArcPad - some practice with the basics

Editing in ArcPad is, in most ways, much simpler than Editing in ArcGIS.  The basic concept is the same in both - data are entered into a file that is open for editing.  Below are a few of the basics.  A complete description of the software can be found in the ArcPad 10 folder in the class folder.

1. On a classroom computer, open ArcPad 10 from the Start Button>All Programs menu in Windows.
    
2. Click the folder button at the top of the ArcPad window and select  "Open Map", then browse to your ArcPad map file, the one with the ".apm" extension, in your "ArcPad_RR_XX" folder.
   
   
3.  Five toolbars are immediately available (called Main Tools, Browse Tools Edit Tools Quick Capture and Navigation), though only one at timeis displayed  (this saves real estate on small screens).

4. Click the Main Tools icon (on the left in the figure above) and then select the Layers icon to open up a Table of Contents, like that on the left below.  The diagram on the right, from an earlier version of ArcPad, has many of the icons labeled.

5. The check boxes on the left in the "eye" column turn layers on and off for viewing.  The check boxes in the "pencil" column turn layers on and off for editing.  This is similar to setting the "Target" of the editing toolbar in ArcGIS, except that in ArcPad more than one layer can be open for editing at a time.  In the Table of Contents to the right above, none of the layers are open for editing. In the table of contents on the left above three layers (Point, Line, Polygon) are open for editing. Finally, the check boxes below the Info icon (i) make layers available for query.  Layer Properties can be accessed by an icon on the right, as can other options denoted by icons that should be familiar from ArcMap.  The column with the "rocket ship" icon at the top is the QuickDraw mode; checking boxes here allows the different layers to be drawn to different "coarseness" so they will render quicker on screen.  The QuickDraw mode is accessed from the Editing Toolbar.

6. Turn on the "Point_XX" layer for editing and close the Table of Contents.

7. Turn on the Edit toolbar by selecting it from top row of icons, as shown below.

8. The function of the edit tools are shown in the figure below.  This is the most important toolbar for the field work this weekend.  Learn it.

To add a point to the map, Click the pencil tool, select the layer you want to edit, click the "Capture a point feature" button, (Capture of polyline or polygon features, if open for editing in the TOC, can be selecting from the drop-down menu below the "capture a point" feature icon). Then click a location on the map.  A data entry form should then open, allowing you to select the feature name from a drop down list.

To do outdoors: To add a GPS location as a point, click instead the "Capture a point using GPS" button. (When the GPS is active this button is not grayed-out.)

9. To add a line, click the Pencil icon, select the polyline feature class you want to edit, click the drop-down arrow below to the "Capture a point feature" button, and select "Polyline".  Click on the map where you wish to place a polyline vertex, click and drag on the next spot where you want a vertex, and continue this process until finished.  The line is not completed until you click the "Proceed or complete feature" button at the bottom of the ArcPad window (shown below).

10. To do outdoors: To add GPS vertices to a polyline, as above, click the "Capture a polyline" button (beneath the capture a point button), click the "Add a single vertex from a GPS position" button and continue clicking this button every time you want to add a vertex to the line.  To finish the line, click the "Proceed or complete feature" button, the green arrow icon. The line is not completed until you click the "Proceed or complete feature" icon.
    
    The GPS must be activated before the GPS buttons are available. 

11. A similar procedure is used to capture polygon vertices with and without GPS.

12. You can delete features by selecting them with the Arrow button (shown above) and then clicking the "Edit vertices" button.

13. Practice adding and deleting lines, points and polygons to the map.  Name the features test1, test2, etc. so that, if needed, you will be able to recognize and delete them later.

14. Browse the ArcPad manual in the digital books folder, particularly the sections on editing.  Download and print the ArcPad Quick Reference page.

15. Before loading your Barton Creek ArcPad folders to the field GPS units, clear each of your test features, or don't save your project after editing.

8B.2

1. Before our field trip, you need practice using ArcPad with a GPS. An ArcPad project for the Main Building area, identical to the ArcGIS project you constructed in Lab 6, is loaded on all instruments.  Take your instrument outside, open the Main Building project, and practice capturing lines, points and polygons using the ArcPad GPS tools described above.

2. Specifically, capture the features listed and labeled in the photo below.

• Points: Points at the two flagpoles.
• L1, L2, L3: Polylines with at least 3 GPS vertices at the edges of sidewalks.
• P1, P2: Polygons outlining grass areas - capture the vertices of the 4 corners with GPS.

You're done.