Open loop Doppler technology for the Mars Express tracking experiment

Using the radio telescopes in the Chinese very long baseline interferometry network (CVN) and sampling board, we have developed algorithms that extract open loop Doppler information from the radio tracking data of Chang’e-1 and Mars Express. Our latest results indicate that the Doppler residuals are about 1mm/s in 1s integration time, relative to an 8.4GHz carrier. Open loop Doppler data have been used in the orbit determination of Mars Express.