The application of MEMS GPS receiver in APOD precise orbit determination

APOD is a Nano satellite manufactured by DFH co., and carries dual-frequency GNSS (GPS/BD) receiver, density detector, SLR reflector and VLBI beacon. In this paper, the inflight performance of the MEMS GPS receiver has been assessed, including the multi-channel satellite ability and orbital accuracy. The average number of tracking GPS satellites for dual-frequency is only 5 due to the low tracking ability of L2 frequency. The mean RMS of ionosphere-free combination carrier phase is approximately 1-2 cm. The routine orbit determination with 36 hours tracking data has been performed using NPOD, the orbital accuracy is assessed by overlap comparison and SLR validation. The results show that the orbital accuracy is better than 20cm in three dimensions in most cases, which is helpful for the study of atmosphere density.