Vector-sensor Doppler Positioning Research

Aircraft torpedo, launch from Anti-submarine aircraft, is one of the main anti-submarine measure for combating with quiet type submarine. In view of the strong burstiness of airplane torpedo, the existing systems of submarine defensing against a torpedo have not met the requirements. So a system specially for withstanding aircraft torpedo with discovering helicopter deck carrying torpedo early should be developed.Based on an important feature of strong aircraft radiated noise from anti-submarine helicopter, Doppler passive ranging of vector sensor achieves detection and localization of the helicopters. And the key technique is the efficient estimation of helicopter azimuth and radial velocity, which was obtained by means of extracting features of radiated noise which is transmitted into water when sound goes by the air-water interface. One vector sensor can be achieved omni-bearing and unambiguous orientation without influence of frequency, so the thesis propose two methods of passive ranging based on a vector sensor,and simulate specific implementation process of the proposals, moreover the method used to process follow-up experimental data.In order to realize the estimation of azimuth and radial velocity, and then realize passive ranging of helicopter, the message of orientation and frequency from radiated noise of helicopter should be extracted. The proposal use method of cross-spectral-weighted histogram which is conducive to line spectrum to estimate the orientation of helicopter, because air target radiated noise in the low frequency is line spectrum-based. Frequency is obtained by adaptive frequency estimator with small amount of computing and high estimation accuracy, and receives prior information via DFT.In the follow-up test data processing, a post processing method consisting of"round filter"and"α?βfilter"is introduced. The method can effectively eliminate flaw points, and the method is validated by simulating and experimental data processing.The results of simulation and experiment declare that the method of passive ranging presented in the thesis can realize targeting. So as the preliminary study for combating air anti-submarine, the method has certain value.