GPS kinematic carrier phase measurements can be used to determine seven di mension state and three attitude parameters of a motional carrier, such as an aircraft or a low earth-orbit spacecraft,on which an antenna is installed to receive GPS signals. It is known from airborne GPS test results for photogrammetry in China since 1994 that GPS carrier phase measurements in a motional environment have acquired external accuracies of ± 7.9cm for two dimensional positions and ± 18. 1cm for point heights. This paper describes airborne GPS carrier phase measurements with multireference stations and discusses how to evaluate the confidence of GPS kinematic data.