I have been given what I'm told are differential corrected gps points (DGPS) and asked to convert them to something usable in current GIS (e.g. Arcgis, Qgis).

They have names like R081320a.cor, R081323a.cor and assuming the file time stamps are accurate were created in 1999. Opening with a text editor reveals a binary format, with the first legible text as MCORR400 v4.55 W32, followed a little later with Automatically Created By GeoExplorer and Geo-Explorer Version 2.20.

Given the context, the GeoExplorer mentioned is probably the Trimble flavour, which needless to say I don't have.

What are my options for recovering these data?

  • Digging through our archives I found a cd with v3.1 of Trimble Pathfinder Office, and the original box with manuals and serial number for Pathfinder Office v2.11. From the user notes in the box, this probably came with the same unit used to capture the points I'm trying to recover (along with a repair invoice for $1300). Naturally the installer for v3 rejects the v2 serial number. Death to closed and proprietary formats! May 30, 2012 at 17:05

2 Answers 2


TerraSync (formerly Trimble GeoExplorer Software)


supports background formats .cor (also shapefiles)

Free Trial of TerraSync http://www.trimble.com/terrasync_ft.shtml

Second option and maybe easier if have the budget and ArcGIS 10

Trimble® GPS Analyst™

NOTE: Only data collected with supported Trimble receivers can be differentially corrected with GPS Analyst extension. http://www.trimble.com/mappingGIS/gpsanalyst.aspx?dtID=applications&

  • I tried installing the windows desktop free trial but it didn't work. A TerraSync folder was created in C:\Program Files (x86) but all it contains is 2 .dll's and a html help file giving keyboard shortcuts and what not. The download page mentions Win95 thru XP but not Vista or Windows 7. I don't think the program can be installed on current architecture. Seperately, I called Trimble tech support, got voice mail and a promise to call back "in the order it was recieved" (that was an hour ago). Looks like I might have to try and hunt down a WinXP or earlier virtual machine... May 30, 2012 at 17:44
  • A VM is what I use for older software
    – Mapperz
    May 30, 2012 at 19:00
  • Finally managed to resurrect an XP VM and install the TerraSync trial --> Epic Fail. The trial version only works with the sample data provided in the download package and it's resultant files are not usable in any other software, including Pathfinder Office. Trimble tech support did eventually get back to me, about 3 days after I placed the call. Their suggested solution: buy TerraSync or Pathfinder Office or contact reseller contractor services and pay them to convert the data --> Epic Fail. I will not allow my organisation to go anywhere near these guys again if I have any say! Jun 25, 2012 at 18:53

I eventually located a licensed version (2.51) of Pathfinder Office in another department which a) did not require a hardware key to use, and b) installed and ran on a Windows XP virtual machine.

In order successfully export to shapefile I needed to go into the advanced options screen under export and check all options under the [Attributes] tab, and also check the boxes for "create point features from Notes, Velocity, and Sensor Records". There is a pdf document called "Exporting into an ESRI Shape File from GPS Pathfinder Office" from California Surveying and Drafting Supply (link points to Google docs quick view, I don't know if that works for everyone.) which covers the process. It's for version 5 but most of the options were pretty much the same.

Before setting the advanced options the Export utility would say things like "1587 positions read. There are no features to export".

Don't forget to set the coordinate system manually for the shapefiles afterwards, as Pathfinder Office doesn't create a .prj file. Unless you change something it will be WGS 1984.

We had two licensed copies of Pathfinder Office, v2.11 and v2.21, including hardware dongle, but neither of them would install or run properly on our current hardware or virtual machines.

Moral of the story: future proof your data. Storing a plain text copy only takes an extra minute or two and can save a lot of headache and money next decade.

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