PRECISION ON BOARD

摘要

Onboard orbit determination simulations for the Swarm-C satellite with real-world flight data and precise real-time orbit and clock products from Fugro have achieved sub-decimeter 3D rms orbit errors. When the GPS orbit and clock corrections are continuously available, 6.8 centimeters 3D rms can be achieved. With conservative assumptions for correction data gaps at latitudes beyond 66° N/S, the 3D rms errors are still just 8.5 centimeters. This result fulfills the accuracy requirements of, for example, radio occultation missions with sufficient margin. This is an important result, as it allows us to shift the POD process from the ground into the spacecraft for future missions and thus provide a precise orbit solution without delay, with possible implications for onboard processing of science data, now-casting of meteorology data, or open-loop instrument operation of radar payloads.