GNSS Bias Calibration System: GNSS-BICS system prototype

Nowadays the estimation of the differential group delays amongst different navigation signals is performed at the different GNSS Control Centres by processing GNSS multi-frequency observables gathered by ground sensor stations. A significant improvement can be envisaged if the estimation is aided by multi-frequency observables from GNSS receivers onboard LEO (Low Earth Orbit) satellites. This aiding may enable the estimation accuracy to become better than a few centimetres (1-σ) in a 2 hours period, while currently the estimations at the different GNSS Control Centres are approximately 10-15 centimetres (1- σ) accurate. In this paper a prototype for the system defined for the calibration of GNSS Signal In Space Biases Amongst different Frequencies (SISBAF) is described.