Magellan MobileMapper 6 GPS – Part 3

In part 2 of the MobileMapper instructions we collected data in the field. Now we are going to move our data from the Magellan to the PC and post-process it to improve spatial accuracy.

Move data from the Magellan to the PC

On your PC/Laptop you should have a designated folder for your GIS/GPS work, say C:\dissertation\GIS. If such a folder does not exist, create it.

  • If your PC has an SD Card reader:
    1. take the SD card out of the Magellan and put it in your card reader.
    2. Using Windows Explorer, navigate to the SD Card.
    3. Here you will find
      • a folder with your name, containing the shapefiles you edited in the field, e.g. samplesites.* and the map file you created for the fieldwork, e.g.  karl260609.map.
      • a folder GPS Raw Data containing the raw GPS data data needed for post-processing.
    4. Move both folders from the storage card to your PC, e.g. to C:\dissertation\GIS.
    5. Put the SD card back into the Magellan.
  • If your PC/Laptop does not have an SD Card reader:
    1. In a previous step you should have installed Microsoft Active Sync (Win XP) or Windows Mobile Device Center (Vista) If you have not installed it yet, install it now. The following steps assume XP.
    2. Connect the Magellan to your PC with the USB cable and switch it on.
    3. Using Windows Explorer, navigate to My Computer > Mobile Device > My Windows Mobile-Based Device > Storage Card.
    4. Here you will find
      • a folder with your name, containing the shapefiles you edited in the field, e.g. samplesites.* and the map file you created for the fieldwork, e.g.  karl260609.map.
      • a folder GPS Raw Data containing the raw GPS data data needed for post-processing.
    5. Move both folders from the storage card to your PC, e.g. to C:\dissertation\GIS.
    6. Disconnect the Magellan.

Install post-processing software

We post-process our data using a software tool called MobileMapper Office. If this software is not installed on your PC, install it now:

  1. Download the MobileMapper Office 2.0 software and extract it to your local drive (e.g. to the Desktop). This creates a folder Mobile Mapping v2.0 CD.
  2. Open the folder Mobile Mapping v2.0 CD and double-click setup.exe
  3. From the menu select the option Install MobileMapper 6 Office 1.0.
  4. Accept all defaults.
  5. After installation completes, MobileMapper Office launches automatically. Cancel and close it for now.

Get post-processing reference data

In short, post-processing compares the data you collected in the field to reference data from a GPS base stations and adjusts your data accordingly.

For locations in the UK we use RINEX reference data, provided by Ordnance Survey (OS). For information on RINEX see the OS website.

  1. Go to http://gps.ordnancesurvey.co.uk/active.asp, search for the RINEX data corresponds to your survey and click Process.
  2. On the next page download your RINEX data. It comes as a ZIP file.  Extract it, e.g. to C:\dissertation\GIS\RINEX. This creates two files for each reference station seletced.

Post-process

  1. Go to Start > All Programs > Magellan > Mobile Mapper 6 Office
  2. Load the data you collected in the field:
    1. Click the top left blue button and select Open.
    1. Select the map you were using in the field, e.g. C:\dissertation\GIS\karl260609.map. This loads the map into the display as it was on the MobileMapper device.
  3. Load the raw GPS data:
    1. This raw GPS data was recorded by the Mobile Mapper device along with your features. This is the data that will actually be processed. Click Add Rover Raw Data and select your raw data file, e.g. C:\dissertation\GIS\526209071000.grw.
    2. The raw data file is loaded and listed in the bottom table.
  4. Load the RINEX reference data:
    1. Click Add Reference Raw Data > From File and select the RINEX data you downloaded, e.g. C:\dissertation\GIS\MANH191q.09o.
    2. The reference data file is loaded and listed in the bottom table.
    3. Repeat until all reference files are loaded.
  5. Click Start Processing.
  6. When processing finishes, the application automatically shows the corrected features. The original features are copied to a backup file, e.g. samplesites_bak.shp.

Done! According to Magellan, with post-processing the accuracy of your features is 1-2m in X and Y. In practive I found it to be even better.

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8 thoughts on “Magellan MobileMapper 6 GPS – Part 3

    1. It has been a while since my initial MobileMapper posts and now I have some feedback from Beth (PhD student and the Magellan’s principal user). She complained about:

      • At one occasion the MobileMapper ‘forgot’ the setting for recording raw data
      • Stability and performance problems with the MobileMapping software
      • Small screen and fiddly buttons and menus

      I have not checked or reproduced the technical problems she reported, so I cannot confirm. In any case I still like the Magellan device for its relative simplicity and consider it good for semi-professional and occasional use.

  1. Though the Active sync 2.4 is installed to the computer the Megallan Mobile Mapper GPS is failed to get connected to the computer. Why is that?

    There is also an option called “live search” when the GPS get started. How to remove or dissable it?

    1. Hm, don’t know why ActiveSync would not recognizing the GPS. I would start investigating by connecting another device that supports ActiveSync and see if that is recognized. If it is recognized, the problem is with the GPS, if teh other device is not recognized, the problem is with ActiveSync.

      Have not seen ‘live search’ on mine – maybe you have a later software version.

  2. i recently got the mobile mapper6. i have been trying to find a suitablle basemap for southern africa with no luck. Any one with ideas where i can get the maps

  3. The link provided to download mobilemapper doesn’t work. I’ve found other links for the software but the post processing function doesn’t exist.
    Any help on what to do?

    1. Thanks for pointing out the broken link, I fixed it. It seems that in the meantime the MobileMapper products were sold under the Ashtech brand. A mirror of the Ashtech software site is at http://www.ashgps.com, and the MobileMapper 6 downloads are at ftp://ftp.ashtech.com/Mobile%20Mapping/MobileMapper%206/.
      It seems Ashtech then were taken over by Spectra Precision (which belongs to Trimble ) so the latest MobileMapper models are sold under the Spectra Precision brand. Almost as confusing as the ErdasLeicaGeosystemsHexagonErdasIntergraph story.

      Why do you not have post processing? Post Processing is an option on the MobileMapper 6 software, so you need two license codes, one for the MobileMapper software, and one for the PostProcessing option. If in doubt check your invoice or with your supplier that you have actually purchased the post processing option.

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