Improved GPS-Based Single-Frequency Orbit Determination for the CYGNSS Spacecraft Using GipsyX

• Main Authors: Axelrad, P. (Author), Conrad, A.V (Author), Haines, B. (Author), O’brien, A. (Author), Zuffada, C. (Author)
• Format: Article
• Language: English
• Published: Institute of Navigation 2023
• Subjects: antenna calibration; Antenna calibration; Calibration; CYGNSS; Geodetic satellites; Global positioning system; GRAPHIC; Ionospheric effects; Multi-path effect; Orbit determination; Orbits; Precise orbit determination; Processing method; Satellite antennas; Single-frequency; single-frequency POD; Single-frequency precise orbit determination
• Online Access: View Fulltext in Publisher

 This paper presents methods for the precise orbit determination (POD) of a satellite in the CYGNSS constellation based on available single-frequency GPS code and carrier measurements. The contributions include the development and eval-uation of procedures for single-frequency POD with GipsyX, improvement of CYGNSS orbit knowledge, and an assessment of its final accuracy. Ionospheric effects are mitigated using the GRAPHIC processing method, and spacecraft multipath effects are calibrated with an azimuth/elevation-dependent antenna calibration map. The method is demonstrated using comparable data from the GRACE mission, from which we infer the expected accuracy of the CYGNSS results. Processing more than 170 days of data from each mission, a 1σ CYGNSS orbit accuracy of 2.8 cm radial, 2.4 cm cross-track, and 6 cm in-track is demon-strated. We expect that achieving this level of performance will expand the set of future scientific investigations that can be undertaken using satellites equipped with single-frequency GNSS. © 2023 Institute of Navigation.