Article Title

Semi-analytical acquisition algorithm for repeat-groundtrack orbit maintenance


repeat-groundtrack orbit, orbit acquisition, orbit maintenance, semi-analytical acquisition, algorithm, CFOSAT


In this paper, the orbit acquisition and maintenance strategies for the repeat-groundtrackorbit are investigated to maintain the ground track of the satellite within a certain range.Two kinds of orbital dynamics models are introduced to calculate the on-orbit state ofsatellite. One is the orbital propagation model which is of high fidelity and can approximatelyexpress the forces acting on the satellite. The other is the design model which is of lowfidelity and utilized by the semi-analytical acquisition algorithm to yield the reference repeat-groundtrack orbit. Combining the differential correction and analytical expressions, theresults computed by the semi-analytical acquisition algorithm are of relatively high precisioncompared with the genetic algorithm. At the same time, the computational burden of thesemi-analytical acquisition algorithm is far less than the genetic algorithm. Based on thereference orbit, two orbit maintenance strategies which are designed for chemical and electricengines are put forward to correct the orbit in order to make the ground track of satelliteshift in a certain range. The application to the Chinese–French Oceanic Satellite missionhas well validated the feasibility of these two strategies. Simulation results have shown thatthe strategy designed for chemical engine can keep the ground track displacement within200 m, while all the orbit points can possess sub-meter repeat distance through adopting thestrategy designed for the electric engine, which satisfies the requirements of the Chinese–French Oceanic Satellite mission.


Tsinghua University Press