A Study On Bearing-only Multi-target Location Based On Data Fusion

Bearing-only target location technology refers that the reconnaissance equipments which do not transmit radio signal conditions to the target which is detected, but to determine the position and the track information of the target by the photoelectric energy radiated by the target itself. Because it doesn’t transmit signal to the target, it has good imperceptibility. It has been the focus of military applicaitons research all the time, of course been the difficulties of the study as well.This thesis bases on the aerial detecting platform and aerial target detection and location for application direction. With the analysis of the current algorithms of bearing-only location, this thesis presents algorithm and the model of the bearing-only of target location based on data fusion. The method firstly estimates the motion parameters of target position, velocity through the algorithm of Shifted Rayleigh filtering with the data measured by the platforms, then uses the optimal weighted fusion based on the error for the results fusion of the targets, so as to obtain the targets’ motion parameters. This thesis mainly makes the research on the contexts below:1. Introduces the background of the bearing-only location problem, its meanings, its technical characters, the situation of its research at home and abroad, and also gives the innovation of this thesis.2. Discusses the mathematical modes of the bearing-only problems under the Cartesian coordinate system and the Polar coordinate system, provides the main current algorithms on the location problem, and makes the comparisons of all the algorithms and shows the advantages and disadvantages of them. Especially with emphasis on the algorithm of Shifted Rayleigh Filter (SRF) which this thesis utilizes.3. Presents the theory of the data fusion, including the definition, classification, its function structure diagram. And on the basis of the above, it proposes the scheme of bearing-only based on data fusion multi-target location. And it makes research and discussion on the mathematical modes of the situations based on single platform under the framwork of single target, multiple platform of single target and multiple platforms and multiple targets. Then it puts forward a kind of data fusion algorithm based on error optimal weighting. And to be aimed at the problem of the multi-platform of multi-target situation, this part proposes a solution on the basis of the Shifted Rayleigh Filter and the Nearest Neighbor (NN) method to have the measured track fused.4. Finally, it gives the exact simulations under the situations of the single platform of single target, multi-platform of single target and multi-platform of multi-target, and has the results analyzed. The results show that the algorithm is feasible, and it has the good effect of target locaiton.