Protocols

KBS039: GPS Protocol for the LTER Laboratory

In use from sometime

KBS LTER GPS Protocol

Materials

Hardware

The KBS LTER has two identical Trimble GPS units. “GPS I” is
to be used exclusively by the KBS LTER staff. “GPS II” can be
loaned to others with permission by the LTER Project Manager.

Two components make up each GPS unit: the Trimble Data logger
type TSCe with touch screen, and the Trimble Receiver Type Pro
XRS model 33302-51.

The GPS can be used in temperatures from -4 F to 140 F. The
logger is designed to withstand accidental immersion so it should
be fine to use it in the rain.

The data logger is set to power off after 10 minutes of
inactivity to conserve the batteries.

Start, Settings, Control Panel, Power Off tab, <On
Batteries suspend after: 10 minutes>

Software

  1. TerraSync – Used for collecting and updating GPS data on
    the Trimble data logger.
  2. Trimble GPS Pathfinder Office (Version 2.9)- Used to manage
    and process GPS data on the PC.
  3. Microsoft Active Sync 3.1.0.9558 – Used to connect your PC
    to the Trimble Data Logger in order to transfer data.
  4. Omnistar is a GPS service that gives real-time
    differential correction. The Omnistar service will be
    maintained on “LTER GPS I”, if funding allows. Omnistar service
    will not be purchased for LTER GPS II unless another user
    requests to borrow the unit and pays for the Omnistar service.
    See the Appendix for service details.

Set Up

GPS Mission Planning

GPS mission planning allows you to determine what time of day
the satellites are in suboptimum position so that you can avoid
collecting GPS data during these times. Mission planning is
critical when collecting GPS data in forested areas or other
challenging sites (see “Collecting Data in Trees or near
Obstructions” in the Appendix).

  1. The Planning Software should be installed on the two
    computer’s in the Robertson Lab that have Trimble’s GPS
    Pathfinder Office software, however, if it is not installed
    then do the following.


    1. Go to Trimble website: http://www.trimble.com.
    2. Click on: <Support and Training>
    3. Scroll down and click on: <Planning Software>
    4. Click on: <Downloads>
    5. Download: Trimble Planning Software
  2. Update the ephemeris file if it has been more than one week
    since it was last updated.


    1. Go to Trimble website: http://www.trimble.com
    2. Click on: <Support and Training>
    3. Scroll to and click on: <Planning Software>
    4. Click on: <Downloads>
    5. Download: <Ephemeris File> Save it to D:\Program
      Files\Common Files\Trimble\Almanacs\current.ssf.
  3. Open GPS Pathfinder Office.
  4. If the <Select Project> window appears, deselect
    “Display this dialog at start-up”.
  5. Click <Utilities> on the Tool Bar.
  6. Scroll down to <Quick Plan>.
  7. <Select Date> window appears. Choose the date of
    interest, and click OK.
  8. <Edit Point> window appears.
  9. Choose <City> and select Battle Creek, MI
  10. The Status window opens.


    1. Choose <Options> on the Tool Bar and scroll to
      <Elevation Mask>, enter 10 degrees.
  11. To view the PDOP status


    1. Click <Graphs> on the Tool Bar, and scroll down to
      PDOP. A graph of PDOP over time will be displayed. You should
      plan to do your GPS data c

      Abstract

      The
      LTER GPS units are used for recording the locations of microplots, experiments,
      instrumentation, plot corners, sampling sites, events and many other LTER
      features that need to be mapped in the LTER GIS.
      They are also used to navigate back to these locations.

      When
      using the Trimble XRS Pro GPS with the Omnistar real-time correction service,
      we can expect submeter accuracy (+ 70 cm or better).

      Protocol

      Author: Tim Bergsma

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