Research On Passive Location Technologies Based On Phased Array

Information Warfare which is omni-bearing, multi-level, and large-depth is based on EW(Electronic Warfare) in the future high-tech warfare. EW is the most important approach towin the military initiative. Modern warfare emphasizes anti-interference concealed attack.The living environment of active location system is hostile in the modern battle-space. Theadvantages of passive location technology are high concealment performance, strong survivalability, far-distance and various kinds of target detection. Passive location technology has aspecific significance, and broad prospects for development.Location accuracy is an important parameter to measure the performance of passivelocation system. The main measurements are based on geometric dilution of precision,circular probable error, ambiguous location area, maximum distance error, etc. However, allthe analysis is based on the absolute error of location parameter, and there are a fewlimitations as an objective measurement.The background of the article is passive phased array radar. The angle parameterobserved value of target emitter is achieved by classical MUSIC DOA estimation algorithm.The physical model of cross-bearing location is analyzed in detail, and the channel model ofcross-bearing location is established by information theory. The accurate decoding problem isequivalent to the accurate location problem. The channel capacity is used as the measurementof location accuracy on the relative error of cross-bearing location. The relative error of cross-bearing location decreases with increasing the channel capacity, and location accuracyincreases. The computer simulation chart and data show that the criterion of channel capacityis superior to Geometric Dilution of Precision, Circular Error Probable, Ambiguous LocationArea, and Max Distance Error. The criterion of channel capacity is an objective andcomprehensive evaluation. The conclusions provide theoretical support for the rapidconfiguration of stations, and the accurate passive location is achieved. The channel model isalso extended to the location system which is based on bearing, phase difference rate ofchange, Doppler frequency rate of change.However, the number of target emitter is unknown in the multi-station passive location.The angle parameter is an incomplete description of the location parameter, and a good deal of false location targets are generated through cross-bearing. As the number of target emitterand station increases, the solution of location mutate into NP Hard problem. The differentobservation state is equivalent to the different station network model, and the mathematicalmodel of dynamic observation is established. The key point of false target emitter removed isthat the location parameter of true target emitter is stable and the location parameter of falsetarget emitter is changed greatly in the different observation state. United joint locationprobability (the non-unitary generalized probability) is calculated. The removing strategy offalse location targets is worked out by the cum-prod principle of generalized probability, andthe core of the strategy is the sequential detection theory. The solution of multi-station multi-target passive location is achieved by the removing strategy. The number of observation stateincreases with station, and the length of sequential detection also increase. The cumulativeeffect is obvious, and the result of false target emitter removed is guaranteed. The number ofclustering point set about true target emitter increases, and the location parameter is extractedaccurately through the weighted average based on channel capacity. The locating and trackingof moving target emitter is achieved by the removing strategy through multiple observations,and the movement locus is obtain.