Research On Crucial Technologies For Single Observer Passive Location And Tracking Via Spatial-Frequency Domain Information

As the consummation and complement of active detection systems, passive location and tracking system has been paid much more attention by many countries. Based on the particle kinematics theory, some critical questions on single observer passive location and tracking are touched by using the observed information of spatial-frequency domain in this dissertation. These questions include location principle and method, ranging error analysis, tracking filter algorithms, and accurate parameter measurement in frequency domain, etc. These researches mentioned above provide an important theory foundation and technology support for the design and execution of single observer passive location and tracking system. This dissertation addresses the following elements:Considering the characteristics of single observer passive target tracking systems, an accurate and robust tracking filter algorithm is developed. A coupling between feeble and strong observational items is weakened by transforming state equation and observation equation to the polar coordinates. Robustness of this algorithm is enhanced by using radial velocity as a state variable and limiting its initial estimating error in a certain bound.Aim at single carrier frequency radar pulse signal, an accurate estimation algorithm for Doppler frequency rate-of-change is given by the correlation among pulse groups. Discrete Fourier Transform (DFT) is used to realize the coherent integration, which improves the relative ambiguous frequency estimation precision of coherent pulse group. This algorithm has low computational complexity and high estimation precision for Doppler frequency rate-of-change. An accurate algorithm based on continuous wavelet transform is proposed to estimate the Doppler frequency rate-of-change. According as auto correlating wavelet transform coefficient of signal, phase ambiguity is unwrapped. Its weighted least squares estimation is obtained from measured phase. This algorithm has low signal noise ratio threshold and near optimal estimation performance.Aim at complex radar pulse signal, an algorithm is proposed to estimate the Doppler frequency rate-of-change of LFM signal. According as auto correlating asymptotic wavelet transform coefficient, phase ambiguity is unwrapped, and the effect caused by modulation ratio is eliminated to parameter estimation. An algorithm is proposed to estimate the Doppler frequency rate-of-change of PSK signal. DFT is used to realize the coherent integration among pulses. This algorithm has certain signal noise ratio threshold and near optimal estimation performance. Both LFM and PSK pulse signals can not be processed in single observer passive location and tracking system, this key question can be solved effectively by the two proposed algorithms.A novel algorithm is proposed to estimate the Doppler frequency rate-of-change based on interpulse instantaneous auto correlation. This algorithm can deal with kinds of radar signals and has fine signal adaption, which reduce complexity of system design profitably. The estimated precision of the Doppler frequency rate-of-change can reach Hz/s in a common passive observing condition.