COMPASSO - In-orbit Verification of Optical Key Technologies for Future GNSS - Mission Description

Abstract

All GNSS programs (i.e. Galileo, GPS, BeiDou, GLONASS, etc.) undergo a permanent process of modernization and improvement of their ground and space segments. Driven by increasing user demands, all programs aim at pushing the boundary of today's position, navigation, and timing technologies to pave the way for more flexible, robust, and resilient GNSSs. A promising way to improve GNSS architectures is the use of optical technologies and more specifically: optical clocks and optical inter-satellite links (ISL). Optical clocks could back-up or replace the currently used microwave clocks, having the potential to improve GNSS position determination enabled by their lower frequency instabilities. In combination with optical inter-satellite links, optical clock technologies enable new GNSS architectures, e.g., by synchronization of distant optical frequency references within the satellite constellation using time and frequency transfer techniques. The aim of the COMPASSO mission - which is an ongoing project and has recently finalized the preliminary system design phase (Phase B) - is to demonstrate new optical technologies relating to satellite navigation. Within the mission, various optical technologies will be further developed and tested with regard to space suitability and operational conditions. This paper details the objectives, status, mission scenario, payload setup and the main optical technologies constituting COMPASSO: iodine frequency references, optical frequency comb, and laser terminal for communication and ranging.