Abstract: High precision orbit determination of LEO remote sensing satellites is difficult both in theory and practice. The traditional method can not meet the requirements of the orbit determination accuracy and low computational complexity. So, the interactive multi-model algorithm (IMM) and multi-ratetracking (MRT) method were introduced into the orbit determination. And a novel orbit determination algorithm was proposed based on IMM and MRT. Low kinematics model error was achieved by IMM algorithm. According to the linearization degree of the models, Kalman filter or particle filter was choose respectively to improve the filtering accuracy. Meanwhile, original observation data was compressed in pattern space to reduce the computationalcomplexity. The proposed algorithm is better than the traditional Kalman filter algorithm, and can improve the accuracy of about 47%. While the computational complexity reduces about 40% compared with particle filter algorithm. The results show that the proposed method can efficiently improve the orbit determination precision with low computational complexity compared with traditional algorithm. It can meet the requirements on orbit determination for the remote sensing satellites.

Key words: Orbit determination, Multi-rate trackingmethod, Interactive multi-model, Remote sensing, LEO