A method for determining the spin axis attitude of a rotating space vehicle, the space vehicle having lines of sight to GPS satellites transmitting GPS signals, the space vehicle having-a navigation solution, the method comprising the step of, generating a difference antenna pattern having a center null, generating a sum antenna pattern having a center peak, receiving the GPS signals by the sum antenna pattern for providing a sum GPS signals having a peak signal at the center peak, receiving the GPS signals by the difference antenna pattern providing difference GPS signals having a null signal at center null, recording the sum GPS signals and the difference GPS signal by time, the sum GPS signals and difference GPS signals being recorded by time for time cross referencing the sum GPS signals and the difference GPS signals, determining the navigation solution of the rotating space vehicle from the sum GPS signals, determining respective centroid locations in the difference signals, determining azimuth angles between the GPS satellites and the space vehicle from the centroid locations and the sum GPS signals, and determining the spin axis attitude of the space vehicle from the azimuth angles and the predetermined navigation solution.
Patent Number: 6452543
Issue Date: 2002 09 17
Inventor(s): Tseng, Gan-Tai
Yang, Jo-Lien
Johns, Steven Lloyd
Wu, Cheng A.
