Research On Accurate Location Technology Of Disoperative Target

Passive ranging technology does not call for coorperate signal source on the target, and would improve naval shooting trial efficiency greatly. Traditional passive tracking systems are restrictived by such facts as low ranging precision and slow tracking speed, so did not become main force for equip finalizing trial. As the new type intelligente torpedo coming forth, old systems are incapable of detecting and tracking torpedo's trajectory in far distance and with high precision. So a schedule has been brought out to build a locating and tracking system with high performance aiming at disoperative target underwater.Two kinds of passive tracking technique are put emphasise on: one is multi-array bearings-only passive tracking using noise emitted by torpedo, the other is passive localization using torpedo's seeking signal. They can be applied to not only passive tracking system, but also passive ranging SONAR.High precision estimating of azimuth and time delay difference is a key for improving localization and tracking presicion. Vector sensor DOA estimation technique and time delay difference estimation technique are studied in theory and validated by simulations. Single vector sensor is capable of measuring the direction of target. In the distance of 5km, about 1°DOA precision can be achieved in theory and validated by lake trial. So it is reasonable to applying vector sensor to buoys for passive bearings-only TMA. For narrowband pulse signal emitted by disoperative target, a series of time delay difference estimation policy such as coarse time delay difference measure,adaptive frequency estimation,adaptive phase difference estimation,signal grouping are proposed and simulated, which establish the theory basic for passive localization system based on torpedo seeking signal.Bearings-only TMA based on dual arrays need no movement by ship, and makes promising application foreground in naval ship compositive SONAR. With distributing vector sensor buoys, passive underwater acoustic tracking system (PUATS) is a TMA method with more tolerance, higher precision and easier realization facility than bearings-only TMA based on dual arrays. Making use of single vector sensor buoy with high precision DOA ability, PUATS integrats redundant buoys with weights, which reduces blind area and promotes location precision. Multi-arrays TMA needs data fusion to ensure the bearings and the location of same target are accordant. A kind of robust recursive associating arithmetic has been brought forward in this paper.Making use of three sub-array passive ranging technique for refence, a DOA and ranging method employ three hydrophones instead of sub-array fixed on submarine to receive seeking signal from torpedo and measure time delay difference from target to every hydrophones. The cross cycle ambiguity caused by coarse time delay difference measurement is analysed in detail and effective solving approach is proposed. The means above is feasible not only to CW pulses, but also to frequency modulated and pulsatile modulated signal. It is adapt to tracking intelligent torpedoes with diverse signal types and passive tracking of active sonar signal.