Introduction about the preliminary radio science experiment in Chinese lunar landing mission chang´E-3

Radio science experiments have been involved in all of the Chinese lunar missions with different research objectives. In Chang´E-3 landing mission, a 3-way open loop lunar radio phase ranging and Doppler technique was suggested and tested. This technique is modified and updated from early multi-channel one-way Doppler deep space tracking technique developed for Chinese Mars mission Yinghuo-1. In the 1^st preliminary experiments, we obtained 1sps continuous phase ranging data before and after the successful landing period, with a resolution of 0.5 millimeter or better. This method, called Lunar Radio Phase Ranging (LRPR) can be a new space geodetic technique to measure the station position, earth tide and rotation, lunar orbit, tide and liberation, by means of independent observation, or to work together with Lunar Laser Ranging. Also, it can be used in future Mars mission.