Lab 3: GPS Data Collection

Introduction:

The goal of this lab was to become familiar with the Trimble Juno GPS unit and its Esri ArcPad software by using it to collect point, line, and polygon features on campus, then translating them to Esri ArcMap. The objectives of the lab were as follows:

1. Create a geodatabase.
2. Prepare the geodatabase for deployment to the Trimble Juno for field data collection using ArcPad Data Manager.
3. Load the Geodatabase onto the Trimble Juno.
4. Become familiar with the basics of the Trimble Juno GPS and ArcPad through an instructor led demo.
5. Collect point, line, and polygon features in the field using ArcPad on the Trimble Juno GPS
6. Check the collected data back into ArcGIS from the field.
 

Methods:

I began by creating a geodatabase in Esri ArcCatalog. I then created a number of feature classes for testing purposes, and a few more for collecting the data shown below. I imported a shapefile of the buildings on campus, and a raster image of the area of interest. Next, I used ArcPad Data Manager to check out these feature classes, and got them ready for use on the handheld GPS unit. Then, I connected the unit to the computer, and deployed my data to ArcPad. I then went outside, turned on the GPS unit, and began familiarizing myself with different data collection methods. I then used the point averaging method to delineate three grassy areas on campus. I also used the point streaming method for three more. I also collected six point features, three trees and three light posts. Finally, I used the point averaging method to digitize the footbridge on campus. After collecting my data, I re-connected to the computer and checked in my data. I organized the map to be more cartographically pleasing. This is shown below. (Note: The background image is outdated, so some of the digitized features may appear to be overlapping buildings etc.)

Results:

The different collection methods used yielded similar results, but there were a few small differences. In collecting polygon data, the point streaming method collected points automatically as I walked around the area I was digitizing. This made the polygon's corners duller, because of the way I walked around them. Also, this caused there to be more variablity around the edges, as the GPS unit has some degree of error. The point averaging method yielded a more precise deliniation, but it was more time consuming, as I had to add each individual vertex. It also worked well for deliniating the walking bridge.