Three-way Doppler observation of Mars Express

Using the radio telescopes in Chinese VLBI Net (CVN) and the sampling board, we have developed algorithms that extract three-way Doppler information from the radio tracking data of Mars Express (MEX) - a Martian probe that belongs to European Space Agency (ESA). Our latest results indicate the accuracy of three-way Doppler is about 1 mm/s in 1 second integration time, relative to an 8.4 GHz carrier. The three-way Doppler data have been used in orbit determination of Mars Express.