The spacecraft signal correlation approach in China's Delta-DOR correlator for Chang'E-3 mission

Delta-DOR is a powerful radiometric navigation technique in the lunar and deep space exploration. With the deployment of Kashi 35m and Jiamusi 66m antennas, China has the capability to make Delta-DOR measurements for the missions exploring the moon and beyond. This paper has introduced the Delta-DOR system in Chinese deep space TT&C network, including the correlator. Basics of Delta-DOR have been reviewed, and the correlation algorithm to minimize the receiver thermal noise effects and cancel out the signal dynamic contribution has been discussed theoretically in details. Simulations have been made to show that the DOR measurements could be achieved with accuracy of 0.3ns for the Chang'E-3 power descent phase. Besides, preliminary test to validate the potential capability of the correlator to deal with the case of weak signal tracking as low as 1dB-Hz has been made using raw data of ESA's Venus Express.