One fundamental principle of Geo++ in GNSS applications is the rigorous modelling of all acting error components to the best possible precision. This led to the concept of state space representation SSR: all physical errors acting on GNSS observations are separated, modelled and represented by an appropriate and flexible manner. On one hand, SSR allows therefore the effective correction of these errors and on the other hand SSR opens the support of various scalable applications. SSR is not restricted with respect to real-time or post-processing: SSR can serve both application areas.
The state space representation SSR contains time and spatial information on the GNSS state, which is generally maintained in real-time by the Geo++ software GNSMART to derive and provide sophisticated network corrections. The SSR, however, is also stored by GNSMART in so-called SSR-files. These files allow for the efficient extraction of e.g. virtual RINEX observations for any time and location in the area covered by the GNSS network. But the capabilities of the SSR data are not limited to virtual RINEX. Any raw or correction data can be retrieved from SSR in real-time and post-processing.