Abstract
Spaceborne GPS navigation technology is recently studied very actively because it is effective to enhance the autonomy of space vehicles on Low Earth Orbit (LEO). GPS attitude determination uses carrier phase measurements observed at multiple antennas, and especially it contributes to simplification of the GN&C sub-system. The major task of GPS attitude determination is to improve reliability and accuracy. Especially an initial attitude search algorithm, which resolves integer ambiguity of carrier wave length, should not be affected by measurement error. In this paper, we show the algorithm for initial attitude determination by integer search technique. Residuals to be evaluated for initial search are accumulated in order to mitigate the effects of measurement noise. It was proved to be effective by ground field tests. And we evaluated it by aircraft flight experiments, which were conducted in November 2001. Ambiguity solution and attitude can be obtained under dynamic attitude maneuvers.
