From Earlham CS Department
Revision as of 10:10, 23 July 2009 by Gaespin07 (talk | contribs) (Importing Data Files)
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Managing Data Files

This section covers how to download the data from the GPS unit, convert it to the necessary file type, and ultimately integrate it into GRASS.

Downloading Data Files

  • Connect Scout Unit to computer using Serial to USB and USB cables
  • Open the Protrak SCOUT software
  • Select appropriate unit
  • Select Download History Log
  • Follow the on-screen instructions
  • Once the download is complete, repeat the process for all units
  • The data will be stored as GPS files in the following directory:
C:\Program Files\PROTRAK\Data
  • From here, the data can be copied to a separate folder for backup purposes

Converting Data Files

  • Open a web browser to the following page:
GPS Visualizer
  • Select the Convert to Plain Text option
  • Select Choose File and browse the directory to find your desired file
  • Under Plain Text Delimiter, select pipe (|)
  • Under Plain Text Output Units, select U.S.
  • In the Time offset: field, type -4
  • Select the Convert button near the top

You should be redirected to a page with a text box that has the data in text format. Near the top of the page you will see a link with a string of numbers ending in .txt

  • Right-click on the link and select Save Linked File As...
  • Choose a descriptive name for your data and change the ending to .csv, essentially saving it as a CSV file

Importing Data Files

Creating a new GRASS location

  • Launch GRASS
  • On the right-hand side select Location Wizard under Define new location
  • Leave the GIS Data Directory field as is but choose a descriptive name for the Project Location
  • Continue to the next page
  • Choose Select Coordinate System and continue
  • Type in ll for the Projection Code or scroll down the page to find Lat/Lon
  • Continue to the next page
  • Choose Select Ellipsoid
  • Type in wgs84 or scroll down to find it at the end of the page, its the very last entry
  • Continue to the last page and select Finish

The location that we will use to import the .csv files is now set up with the appropriate coordinate system. This will allow us to validate the points' relative locations to each other.

Importing .csv files