# Geo++® SSR2OBS - Online Help

© 2015-2025 Geo++® GmbH

## SSR2OBS - General Overview

SSR2OBS is a utility to convert state space representation (SSR) GNSS corrections to observation space representation (OSR) GNSS corrections to be used in GNSMART.

There are different concepts to model distance dependent error (see for more details also RTCM_OUT). One has to distinguish between

- the "real" physical reference station and its coordinates
- the "visible" reference station and its coordinates
- the localized correction or individualization of corrections

furthermore, the update of the visible reference station's coordinate in the correction stream is for kinematic applications relevant.

The update of the visible reference station's coordinates is a functionality, which must be supported by the rover algorithm and may cause a complete reset of the rover ambiguity resolution.

Geo++® GmbH | $Revision: #16 $, $Date: 2025/09/19 $.