Research On Cycle Ambiguity Resolution Of The X-Ray Pulsar Navigation System

In the increasingly complex competition environment of the space, achieving theorbit compute of autonomous spacecraft can reduce the workload of ground-basedmonitoring system and give full play to the spacecraft’s potential. An X-raypulsar-based navigation is a novel celestial navigation technology for the spacecraftorbiting the Earth, probing the deep space or flying interplanetarily. It has importantstrategic significance for national defense and national economic construction. Forspacecrafts that have failed for some reason and must implement absolute positionnavigation in order to solve the vehicle’s lost-in-space problem or recovery from theextreme cases, there will be an ambiguity problem.As to the problem above, under the X-ray pulsar autonomous navigationapplication background, this paper firstly introduces basic theory of the X-ray pulsarnavigation system, the meaning and principle of ambiguity resolution. Then threesearch methods are elaborated, which are single-difference measurement searchapproach, least squares ambiguity search technique and the classical method ofundetermined coefficients. Each algorithm is completely described from the concept tothe process and made a concrete simulation. Then a pulsar ambiguity solution methodbased on the kalman filter is presented. A simulation is taken based on the theoreticalanalysis. And this algorithm is compared with the other three algorithms, the resultsshow that the kalman filter resolution has a shorter time of the calculation while obtaincorrect cycle ambiguity. Finally, this paper first proposed ambiguity solver results forinitial orbit of the spacecraft in the X-ray pulsar navigation algorithm. The resultsshow that this type of application method is feasible.