Abstract: In order to solve the problem of carrier phase ambiguity and get high precision orbital determination result of GEO satellites and relative positioning of co located GEO satellites in real space missions using connected element interferometry (CEI) technology, a method of solving phase ambiguity of the carrier with the data fusion of multiple passes of downlink signal is proposed. Through adjacent multiple passes of carrier phase delay smoothing narrow band TT&C signal group delay, the unwrapped phase delay observations are obtained. The performance simulation and actual test are performed to verify the proposed method. The results show that on the 20 km baseline, both the pseudo code ranging signal of Beidou GEO satellite and the TT&C signal of Tianlian satellite have successfully realized the resolution of phase ambiguity of the S band carrier, and the phase delay measurement accuracy can reach 0.1ns, corresponding to the GEO satellite orbit determination precision better than 54 m. This method achieves the unwrapped phase delay for the first time in China by just using hundreds of kiloherts narrowband measurement with a baseline of tens of kilometers, and has a good application prospect.

Key words: Connected Element Interferometry (CEI), Interferometry, GEO, Phase delay