TerraPOS is a GNSS post-processing software that delivers better than 5 cm positional accuracy of an airborne kinematic trajectory without base station. It works anywhere in the world. This software suite is based on the principle of Precise Point Positioning and has been developed by TerraTec of Norway, initially for their in-house use.
After extensive comparisons on projects with conventional base stations and proving TerraPOS’ reliability and accuracy TerraTec retired all its ground reference receivers.

Typical kinematic accuracy with TerraPOS

Length of data Horizontal RMS Vertical RMS
>3h 3cm 5cm
1h 5cm 10cm

How is this achieved?

  • You need a survey grade, dual frequency GNSS receiver for airborne use
  • Your data sets should be preferably more than 3 hours long. If your mission is planned to be shorter, run the GNSS receiver in the plane on ground power before or after your flight
  • Download precise orbits and other parameters a few days after your mission. These are post-processed by the International GNSS Service (IGS) and available free of charge. TerraPOS will download the correct parameters for you

Logistics and Costs

Who knows better than you how much logistics and costs you have to bear having a crew collecting base station data at the same epoch rate and during the same period as your flight mission. Weather has its ways to reliably complicate such plans.

Rescue Flown Projects

You have a fall-back solution that can rescue your flown project when the Government or privately operated reference station fails for whatever reasons.

Overseas Projects

For overseas projects you can operate independently from local ground reference stations. TerraPOS works anywhere in the world at all times with the same accuracy.

Make Full Use of Your Current GNSS Receiver

If you have the latest and greatest airborne GNSS receiver, you will make full use of its advanced features through TerraPOS. Your results will not get diluted by whatever base station receiver is deployed for a differential solution.


Your missions should not have total losses of lock. Loosing some satellites in tight turns is no problem. If you do have a total loss of lock, your mission will be cut into separate pieces which may not be long enough for acceptable accuracy.

Your trajectory accuracy will depend on how long you can wait to process the data. If you process right after your mission, results will be good with the available predicted orbits. They will be better, if you can wait for 24 hours to get the rapid orbits. Our experience shows that there is no significant difference between results obtained from rapid orbits and final orbits which are uploaded 7-10 days after your mission.


All internal computations are done on ITRF, the International Terrestrial Reference Frame. We provide several datum transformations and output formats with TerraPOS. For example, through the Waypoint CMB file format, you can load the TerraPOS solution into GrafNav/PosGPS and do your quality checking and onward processing just like a conventional DGPS solution.

Not Yet Convinced?

We could not believe it either at first. Send us a data set and we will process it for you. We need either the raw GNSS data from your airborne receiver or its Rinex files. Data exchange will be through our FTP site. Let us know what datum you want your results. If you would like to try our offer, please email or call us.