Configurable GNSS based orbit determination for LEO-PNT non-operative and operative phases

The LEO-PNT multi-tier approach needs enhanced Precise Orbit Determination (POD) capabilities. During nominal payload operations, the GNSS works as a system generating the broadcast ephemeris and clocks corrections for the target PNT application. However, such LEO infrastructures exploit the on-board navigation also to enable autonomous operations. This work reviews this multi-objective orbit determination task and proposes a configurable Kalman filtering paradigm to support both non-operative (autonomous rising, collision avoidance, routinely station keeping) and operative phases (high accuracy P2OD). The approach is tested on high fidelity simulations considering the state of art of autonomous orbit control and the on-going development of an HAS compatible spaceborne receiver. The analysis identifies the design drivers for a new class of multipurpose GNSS based navigation solutions aiming to improve both LEO-PNT platform autonomy and mission performances.