Space Event Analysis Based On Historical Orbital Data

The thesis mainly concerns on the detection of events in space with historical orbit data, and it consists of determination methods on characteristic orbit parameters, the precision analysis of long-term in SGP4/SDP4model, the effect caused by errors on the correct judgment for orbit abnormal situation, Butterworth â…¡R (Infinite Impulse Response) filtering algorithm, representative MWCF method of space events detection and the detection theory and algorithm based on long-term bias variation. Besides the above mentioned points, this paper also describes the procedure of applying the available detection algorithms and the detection theory based on long-term prediction of orbit deviation which produces a good result..Firstly, the orbit theory is introduced and simulation analysis of SGP4/SDP4long-term error is conducted. The efficiency and rapidness could be achieved merely taking the long-term orbit effectiveness into account.Secondly, a detail study on the variation of characteristic orbit parameter is done with the object of space events quantity. The change of orbit parameters caused by events in space is analyzed in detail. An approach available to assess most space events, in which the key parameters are semi-major axis, the inclination of the orbit and semi-major axis, the inclination of the orbit, the longitude, of LEO and GEO respectively, is also proposed.Next, a brief analysis about filter process of gross error adopting the IIR adaptive filtering algorithms are discussed. An effective method to avoid false alert caused by gross error is suggested, with the procedure including IIR filtering operations on orbit data firstly and conducting the available detection of space events based on the data after filtering.Then, the further study on the simulation of the available detection algorithms based on long-term deviation (MWCF) is performed. This paper demonstrates the detection algorithm based on the theory of prediction of long-term orbit deviation by adding Butterworth filter to it. The facts that the â…¡R adaptive filter helps to avoid false alert by MWCF is demonstrated by simulation analysis later. And the improved algorithm is also effective for space debris detection.Finally, Matlab simulation illustrates the improved detection algorithm for space events with space objects in LEO&GEO orbits, and then verify that the improved detection algorithm with lower false alert rate is effective to detect the space events.