Geo++®SSRPOST is a post-processing service based on GNSMART SSR data and a realization of PPP-RTK.

Test the demo-version of SSRPOST on  Geo++® SSRPOST Demo-Server.

Geo++® SSRPOST enables GNSS post-processing based on state space information derived from a GNSMART network processing. The post-processing uses SSR data from a reference station network and RINEX or receiver specific raw data from one rover. This approach is called Precise Point Positioning-RTK (PPP-RTK).



SSRPOST provides a web interface to the user to process the RINEX or raw data. The user can upload his own collected RINEX or raw data to the server and obtain the processed coordinate for a point or trajectory. The processing on the server is based on the user’s uploaded data and SSR (state space representation) data from the network. This is comparable to the generation of „Virtual RINEX“ for either static rovers, for trajectories (moving rover) or for reference stations. Advantage of SSR or derived quantities compared to original RINEX of a reference station is the station dependent error. Due to the processing of several reference stations and the state space representation, the SSR is free or greatly reduced of any station dependent errors. The noise of the observation from SSR is lower and hence often better than original RINEX.

Backward Processing

The SSRPOST backward processing approach for kinematic data is based on data generated by GNNET and stored for further use. When GNNET is unable to resolve ambiguities, it estimates the coordinates backwards until the last cycle slip using the information from these files. Therefore an ambiguity free (fixed) solution is calculated forward and backwards between two sequenced cycle slips (one block). A high relative accuracy is achieved within a block, although the ambiguities have not been resolved completely.

SSR Generation

The state space representation (SSR) files contain the state space modeling (SSM) information estimated by GNNET. These files can be used for further processing and analysis like SSRPOST or GNWEB. The SSR file generation should optimally be done in real-time within a GNSMART installation. Sometimes it is useful to have the possibility to do the SSR generation in a post-processing environment, based on RINEX input data. The SSR data is estimated in GNSMART by the module GNNET. The state space representation contains time and spatial information on the GNSS state.

Reachable Accuracies

In principle, SSRPOST will achieve at least the same accuracies which are achieved with the underlying reference station network in real-time. Prerequisites are proper local environmental conditions at the rover site (no obstructions, multipath,…).

Nowadays, accuracies in the order of 1 to 2 cm + 0.1 to 0.2 ppm are reachable with sufficiently precise reference station coordinates and the use of absolute antenna calibrations on the reference stations.

 Influences on the rover side, however, can act as limitation on the achievable accuracies.

Demo Version

The demo version of SSRPOST allows to calculate a data set and download the results. Following demo data ( set can be used to test the SSRPOST functionality:

File Description includes a RINEX observation and two RINEX navigation files as well as the corresponding antenna type calibration file
readme.txt contains additional informtion concerning the antenne type calibration file

User name and passwort for the demo access are as follows:

User: Demo-ssrpost
Password: Demo-ssrpost

The demo version of SSRPOST can be started here: