Interference Source Location Research Based On Satellite Array Antenna

As satellite communication develops,its position in the future system of communication networks has become increasingly prominent.Its seamless coverage and large capacity will bring enormous economic and social benefits,as well as a broader prospect for its future development.But then comes the more severe problem of electromagnetic interference in satellite communications,so the positioning and investigation of illegal interference in the satellite coverage area is an essential guarantee for the regular operation and maintenance of the future Internet satellite system.Among the interference source positioning technologies,the joint dual-satellites Time Difference of Arrival(TDOA)and Frequency Difference of Arrival(FDOA)localization technique has attracted a great deal of attention due to its wide reconnaissance range and high positioning accuracy.Still,there are "blind spots" with significantly increased positioning errors,which leads to the problem of unstable localization performance.With the wide application of on-board array antennas,the future low-orbit Internet satellite will further enhance the detection capability of on-board electromagnetic wave Direction of Arrival(DOA).Based on this,this paper offers a dual-satellites positioning technique that combines TDOA/DOA to solve the “positioning blind spot” problem in dual-satellites TDOA/FODA positioning technique.This paper is based on the study of the parameter estimation algorithm and localization solution methods involved in this localization technique.The main work is as below:(1)In this paper,the engineering theory involved in satellite direction finding and positioning is investigated and analyzed.The technique of direction finding based on spatial spectrum estimation is elaborated,and then the theoretical positioning error formula of single-star direction finding is derived.The simulation analysis demonstrates that the positioning error distribution of single-star directional positioning exhibits concentric circle characteristics,and its localization accuracy is sensitive to the directional error,and the localization error curve can approach the Cramer-Rao Lower Bound.(2)Time difference parameter estimation algorithm.Firstly,the algorithmic signal model is established,and the principles of the basic correlation algorithm,the generalized cross correlation method,and the quadratic correlation time delay estimation algorithm are described.A time-delay estimation algorithm based on higher-order cumulative quantities is studied for the problem of correlation algorithm failure in the case of noise with correlation.And the idea of generalized cross correlation algorithm is introduced into the high-order cumulative quantity algorithm to enhance the accuracy of time delay estimation and the noise immunity performance of the algorithm.(3)DOA estimation algorithm in two dimensions.A propagation operator-based DOA estimation method is presented for satellite directional positioning using a satellite-side uniform plane array antenna.The new data reception vector is constructed by subface array division,and the data conjugate rearrangement method is used to reduce the correlation between sources,and finally the propagation operator algorithm is used to obtain the auto-pairing 2D DOA estimates.The experimental data suggests that the algorithm has superior angle estimation performance compared to the conventional algorithm.(4)Positioning solution method.To address the "positioning blind spots" problem of the current widely used dual-satellites TDOA/FDOA positioning system,a dual-satellites interference source positioning technique is proposed to combine with TDOA and DOA,and the improved salp swarm algorithm is used to solve the positioning.The simulation results show that this positioning solution method has better positioning performance,and the simulation also verifies that the combined dualsatellites TDOA/DOA positioning technology can significantly ameliorate the insufficiency of dualsatellites TDOA/FDOA positioning in terms of positioning feasibility and sensitivity of the interference source localization.