Software Correlation Processing Of Satellite Signal Based On DiFx

With high precision angle measurement capability,VLBI(Very Long Baseline Interferometry) technology has the characteristics of track lateral constraint, which helps to improve the precision of orbit determination. Chinese Academy of Sciences National Time Service Center VLBI2010 systems are being developed to establish three stations, using 13 m antenna system, not only observing radio source, also geostationary orbit satellite. Through the geostationary satellite orbit angle measurement, the system will achieve precise orbit of satellites, while the system can be based on the Earth Orientation Parameters(including world UT1 parameters, etc.) measurements, as well as connection celestial reference frame and terrestrial reference frame.The system is currently being developed. The traditional VLBI is mainly used for radio source observation, in this system satellite signals also be required. Satellite signal is an artificial signal, its polarization, the spectral characteristics vary greatly with radio source. How to deal with the satellite signal correlated effectively, is the main problem to be addressed in this article.This paper aims at geostationary satellite signal correlation processing on Di FX. Thesis mainly involves VLBI observation satellite, signal processing algorithms and realization of the correlation process. To solve the above problems, the main contents and results are as follows:(1) At first, introduced the development background, VLBI system composition, general correlation processor and software technology application status of the satellite observations at home and abroad. Based on the principle of the VLBI correlation, presented the FX software correlator signal processing.Describes the installation and basic framework, method of operation of the relevant software--Di FX.(2) compared the downlink signal characteristics of satellite and radio sources; organized BDS, CAPS downlink signal characteristics, as center frequency, spectrum.(3) before the system completed, Take the VLBI experiment platform to complete an experiments. Using GEO satellite track measured 3.7 m antenna received 12 th star satellite signal UTC 08: 08: 36 ~ UTC 08:08:49 in the first nine day in 2015, to get the interference fringes.(4) plus, 13 m antenna of Chinese Academy of Sciences National Time Service Center VLBI2010 system received M1 NGC 1952 UTC 11:05:48~UTC 11:06:02 signal in the first 41 day in 2015. Got power spectrum, delay, rate by self-correlation processed on Di FX software platform.The test results shows that the interference fringes output and bandwidth late can be successfully integrated to obtain. This work help to assist the development of the Chinese Academy VLBI2010 system construction, and support the improvement and systematic research work.