Phase Estimation for Inter-agency Interferometric Tracking in Chang'E-3 Powered Descent Flight

Very long baseline interferometry plays a critical role on the orbit determination of the lunar and deep space probes, as well as the radio science research. Based on a first-order approximation model of the probe's topocentric range-rate, this paper proposes a new narrow band tracking method for the weak signal received by an antenna with relatively small aperture. As long as the Doppler dynamics has been estimated from the signal received by a large antenna with high G/T value, the weak signal, received by the small antenna during the same time duration, could be Doppler compensated. The raw data acquired by Chinese Jiamusi station and European Space Agency's New Norcia station have been processed, and the results demonstrate the effectiveness of this method. Digital phase locked loop with 5 Hz noise bandwidth could be used to track the differential one-way ranging(DOR) tone received by New Norcia, after Doppler compensation by estimation results from Jiamusi carrier tracking, and the root mean square of the tracking phase errors for DOR tone is around 3.4 degree. This method could be used in the radio metric navigation for the future lunar and deep space missions, as well as the inter-agency cross-supports.