New Orbit Determination and Clock Synchronisation Modules for EGNOS

Abstract

graduated from the Ecole Polytechnique France. She currently works as navigation algorithms engineer at Thales Alenia Space on the EGNOS project, more precisely on precise orbit determination. Rabab Lembachar graduated from ENSEEIHT, France. She is a software engineer in the EGNOS Navigation Algorithms team at Thales Alenia Space, currently working on designing and conceiving an Orbit Determination software. Thierry Authié graduated from the Institut National des Sciences Appliquées (INSA), France. He worked in space flight dynamics and precise orbit determination. He currently works as navigation algorithms engineer at Thales Alenia Space on the EGNOS project. Sébastien Trilles is a specialist in navigation performances, working at Thales Alenia Space on the EGNOS Project as Algorithm Navigation Design Authority. He has been in charge of Algorithm studies with the CNES on Precise Orbit Determination and Time System Reference for EGNOS. Flavien Mercier is senior expert in the orbit determination team at CNES. He works on the precise orbit determination for altimetry satellites (TOPEX, JASON) since 2001, he is specialist in GPS processing. He is also involved in validations for the EGNOS team. Since 2010, he is participating to the CNES/CLS analysis centre for IGS ('grg' products).

Integrity Based on MT28 for EGNOS: New Algorithm Formulation & Results

“…The computation of the covariance matrix proposed in this paper is based on a satellite restitution position process combining : -The real pre-processed measurements delivered each second, -The information of the a-priori 3 × 3 orbit covariance coming from a precise orbit determination process (OEP module, Orbit Estimation & Prediction) [3], The covariance information from the real time orbitography modules (OEP) is launched every 120 seconds and computes the orbits and snapshot clocks of the satellites, as well as their covariance. The synchronization module (CEP) computes satellite clocks and stations every 10 seconds with their associated variances.…”

Performances Monitoring and Analysis for KASS

“…The KNT is steered towards the GPS time scale by the KPS Processing Set design. The steering shall be closer than 50ns by requirement, but in practice the gap between the two time references is below 3ns (see [3]). The message the KPS Processing Set sends is the NOF Up Link (UP).…”