Downloading GPS Data Using DNR Garmin
DNR Garmin is an easy-to-use “point and click” software application that allows you to manage, manipulate, and save data from a Garmin GPS receiver for use in GIS programs such as ArcMap, MapWindow and AccuGlobe. DNR Garmin is shareware created and maintained by staff at the Minnesota Department of Naural Resources.
While there are a number of things that DNR Garmin software can do, some of the functions most applicable to Extension agents include the following:
- Educators can use this software package to transfer GPS data between a Garmin GPS receiver and a PC.
- DNR Garmin can save GPS data as projected (or unprojected) shapefiles for use in ArcMap, as graphics, as a database files, or as text files for use in other programs.
- The program allows for initial projection of GPS data (e.g., waypoints, routes) to many different map datums (e.g., Lat/Long, UTM/UPS, country grids).
- Information can be filtered in various ways and waypoints sorted according to specified criteria. Route and track statistics are available and can be transferred into other programs for analysis (e.g. spreadsheet programs).
DNR Garmin unfortunately does not have any self-contained mapping functionality that allows you to view your data before you save it to your computer. Note: DNR Garmin is designed specifically for Garmin GPS units. This guide is written using the Garmin Legend GPS receiver. All other Garmin GPS receivers will follow the same protocols.
Before Using DNR Garmin
The instructions in this handbook assume the following:
- You have already installed DNR Garmin software on your computer. DNR Garmin can be downloaded for free from the Internet. (If not, refer to DNR Garmin Installation Instructions. These instructions have been prepared by the Virginia Geospatial Extension Program, with educators and resource managers in mind. These step-by-step instructions for DNR Garmin are available from Virginia Tech Geospatial Extension Program.
- You have already collected GPS data (e.g., waypoints, routes, tracks) and have stored the GPS data on your GPS receiver.
Start DNR Garmin by selecting it from the program list on your computer.
Starting DNR Garmin Software
- Connect your GPS receiver to the computer using the data cable provided with your GPS receiver. Make sure that your GPS receiver is turned on.
- DNR Garmin is configured to work with all Garmin GPS units and is defaulted on first use to search for a USB connection to your GPS unit. If you Garmin is connected with a USB cable, DNR Garmin will connect automatically with your unit.
- If a serial port connection is being used, DNR Garmin will prompt you to retry to find a USB connection. Cancel this prompt.
For serial port connection, go to <GPS>, then <Set Port>, and select the port being using, most likely Port 1. DNR Garmin will automatically connect to your unit.
Once connected, the status bar on the bottom of DNR Garmin will tell you that your device is connected.
Connecting Your GPS
DNR Garmin will also list the type of Garmin unit you are using and the projection that your data will be projected into once downloaded. Step 4 tells you how to change this projection to one of your choice.
Your GPS should now be properly communicating with your PC through the DNR Garmin Software.
- Now that your GPS unit is connected, you can set up the datum/projection that you would like your data projected to when it is uploaded to DNR Garmin. To do this, go to <File> , then <Set Projection>. This brings you to the Garmin Properties dialog box (This can also be accessed by going through <Waypoint>, <Track> or <Route> and the “Properties” option, then the “Projection” tab.).
Setting up the Datum
- The Properties dialog box will appear with several tabs. Select the “Projection” tab. Here you are allowed to choose from a wide range of datum/projections< from the pull-down menu under “Datums/Projections,” that your GPS data will be projected to once downloaded to DNR Garmin. Once a projection is selected, click “OK.”
You Are Now Ready to Download and Save Your GPS Data
Unfortunately, DNR Garmin does not allow you to download more than one type of data at the same time. You must download waypoints, trackpoints, and routes individually. However, the same method is used. Depending on which type of data you have, you go to the corresponding menu (<Waypoint>, <Track>, or <Route>)and then <Download>. DNR Garmin will automatically download the selected type of data and will display the data as shown below.
Modifying the Datum
Review of terms:
- Waypoints: These are “virtual points” or marks that you have saved in individually. Waypoints can be assigned customized names (the GPS receiver assigns them numerical names [001, 002] by default).
- Tracks: Tracks are a previous path of travel. Basically, you turn on your GPS receiver and it will start to “map your movements.” Trackpoints are individual points that are used to create a track (if you connect these points, with a line, you would have a track).
- Routes: A route is a “path to a destination with intermediate stops along the way.” The “stops” along the way are defined by waypoints.
One feature of DNR Garmin allows you to choose what fields that you want your data table to have once it has been saved. To do this, access DNR Garmin’s Property dialog box through any of the methods mentioned in Step 4. Go to the tab that is related to the type of data you are working with (e.g., tracks). Under “Fields to Use” is your list of fields for your data. You can uncheck/check the combination of fields that you want, or just choose to leave all fields checked. The checked fields will be the fields in your attribute table and database once you have saved the data.
Note: Some fields, such as x and y coordinate fields are required by DNR Garmin and cannot be unchecked. You will be prompted with a message telling you if it is required, though.
Saving Your Data to a PC
You can save the data that you have collected on your GPS receiver directly to a “GIS readable” file (e.g., shapefile).
- Make sure the file that you want to save (e.g., waypoints, tracks) is “visible.
- Under the <File> menu, select <Save To>, and <File>.
- To save in a GIS compatible format:
- Under the <Save As Type>, option, choose either:
- ArcView Shapefile (Projected)- this option saves data directly to a GIS-compatable shapefile according to the user-defined projection
- ArcView Shapefile (Unprojected)- this option saves data directly to a GIS-compatible shapefile as well, but according to the unprojected coordinates directly from the GPS unit.
Presto! You have created a GIS-compatible file from your GPS data.