Doppler Closest Point of Approach for Passive Sonobuoy Based on Least Square

To improve estimation precision of the passive sonobuoy parameters, a least square based Doppler closest point of approach (CPA) is proposed. On the basis of the new Doppler CPA, Doppler information of the characteristic frequency in radiated noise of target is used to construct a rectangular matrix, and the least square principle is employed to obtain the least square solutions to the nearest distance and speed of a target. Then, the error of the algorithm is analyzed using Taylor expansion formula. Computer simulation and air experiments show that the proposed method can calculate the target parameters correctly, and compared with other algorithms of a passive sonobuoy, the precision of target parameter estimation is improved significantly.