CVN software correlator applications in deep-space exploration

Being able to achieve very high angular resolution, the Very Long Baseline Interferometry (VLBI) synthetic telescope is widely used in the deep-space tracking. The software correlator is a novel VLBI data processing technique, which is very suitable for deep-space exploration. This paper introduces the first 10-station software correlator of the Chinese VLBI Network (CVN) and its applications. Based on the commercial symmetric multiple processor server, the CVN software correlator can work in the near real-time and the post processing modes. Besides the normal VLBI data correlation function, it has the abilities of fast fringe search, multi-channel phase calibration abstraction, high frequency resolution which are especially useful in space craft tracking. It was successfully used in the European circumlunar explorer joint tracking experiment and other space craft observations. More than one year operation indicated its characteristic of flexible structure, reliability, scalability. It will be used in the Chinese lunar and other deep-space exploration projects.