Table of Contents
- Creating a Digital Elevation Model from GPS Data Using Interpolation Methods
- Setting up Your Workspace
- Preparing the Data
- Skill Drill: Downloading data using the Minnesota Department of Natural Resources GPS Application (DNRGPS)
- Creating a Surface Model Using the IDW Interpolation Method and the Geostatistical Wizard
- Creating a Surface Model Using the Spline Interpolation Method
- Creating a Surface Model Using the Kriging Interpolation Method
- Creating a Digital Elevation Model from a Geostatistical Layer
- Skill Drill: Creating a Map of the Results
Preparing the Data
The following Skill Drills use the knowledge you have learned in previous courses, including Geospatial Concepts (GSP 101) and Geographic Information Science (GSP 270). Therefore, the instructions do not contain many step-by-step details. You should refer to previous coursework if needed. Registered students may also post questions on the weekly Q&A Discussion Forum on the Canvas LMS.
Skill Drill: Collecting Elevation Data Using a GPS Receiver
Use Google Maps or the HSU Campus map to choose a location on campus, approximately 1 hectare, that contains significant changes in elevation. For example, the area between Founders Hall, the Upper Playing Field, and the Kinesiology & Athletics Building would be an ideal area. It contains varying elevation with few GPS signal obstructions. Alternatively, you may choose another suitable location either on or off campus. Use the map to make a rudimentary data collection plan. Decide where you will begin your data collection and where you will end. Plan how and where you will travel during data collection. For the best results, your waypoints should be distributed as evenly as possible across your area of interest. Avoid clustering your data points if possible. A useful method for doing this is to mark a waypoint about every 10 or 20 strides. Using a GPS unit, collect between three hundred and five hundred waypoints with elevation data. Use what you have learned in Geospatial Concepts (GSP 101) or other previous courses to optimize the accuracy and efficiency of the GPS receiver. Specifically, you should make sure your GPS Unit is WAAS enabled. Also be aware of any obstructions. For this lab, you may team up with some of your fellow students to collect waypoints if you wish. It may be helpful to divide the work between lab partners and merge the data points into one shapefile in ArcMap. You may check out a GPS unit from the HSU Library reserve desk. Students are allowed to check these units out for four hours at a time.