A Rearch About Parameter Estimation Based On Double Baseline Rotating Interferometer

Passive location technology does not need to expose themselves,but to process the electromagnetic signals obtained by target reflection to implement investigation and then determine the target.Because of its good invisibility and the capability in anti-interference and long-range,passive location technology plays a more and more important role in the scitech war today.The thesis mainly analyze the model and method of rotating interferometer on the basis of traditional interferometer.Firstly,it introduces the traditional target parameter estimation methods of far-field and near-field and so a systematic understanding of angulation principle is obtained.Then the angulation methods of near and far target based on Single Baseline Rotating Interferometer(SBRI)are analyzed.After that,the following discusses localization methods of near and far target based on Double Baseline Rotating Interferometer(DBRI).(1)On the basis of SBRI in near-filed,an improved parameter estimation method of nearfield source based on DBRI is proposed.Firstly,the signal model of near-field target is constructed.Then,analyze the principle of solving phase ambiguity and estimation method in detail.Finally,simulations under different SNR and snapshots verify the validity of the proposed method,and the comparison result indicates a higher localization precision of proposed method when contrasts with SBRI.(2)On the basis of SBRI in far-field,an improved localization method based on DBRI is proposed.Firstly,the signal model of far-field target is constructed and a cycle of phase difference vector is obtained by rotating the baselines in opposite direction.Then,introduce the Multiple Hypothesis Nonlinear Least Square to solve the phase ambiguity and locate target.Finally,verify the correctness and effectiveness of DBRI in comparison with Double Long Baseline Interferometer and SBRI.Meanwhile,among the three methods,analyze the probability of solving phase ambiguity correctly in different SNR and discuss the adaptability of different phase error which verifies the robustness of DBRI.