On the estimability of geodetic parameters with space-ground and space-space SVLBI observations

Space Very Long Baseline Interferometry (SVLBI) is the unique space technique that can directly interconnect the main three reference systems for geodesy and geodynamics. However, the estimable sequence of geodetic parameters including nutation parameters within SVLBI mathematical model has not been determined yet. In this paper, using the mathematical model of space-ground SVLBI observations including the nutation parameters derived by WEI Erhu et al.(2008), the estimable parameter sequence is determined. And the same study is done with space-space SVLBI Observations. To study the standard deviation of nutation parameters estimated with space-ground SVLBI observations, the model of variance propagation is derived, with which some numerical tests are done. Finally, the results are present.