Research On Weak Signal Processing Methods For Ballistic Velocity Estimation Radar

Signal detection of Low signal-to-noise ratio and extraction of weak echo signal are the main problems in the field of radar signal processing of Doppler velocity estimation radar system. One of the four threats for radar is the clutter interference from land and sea. And to research and solve the problem with the Non-steady signal processing theory is one of the arousing interests in the field of signal processing. Taking the engineering application background as request, taking the premise of fully utilizing national range existing test facility and technology and positively absorbing the advanced research findings both at home and abroad, introducing the Non-steady signal processing methods such as Wavelet Transform, High Order Statistics, Short-time Fourier transformation etc. into the process of Doppler velocity estimation radar weak echo signal, the paper analyzes the operational principle for velocity measurement and the signal processing techniques of small arms velocity estimation radar in detailed theory and explores weak ballistic information processing theories and methods that are suitable for low trajectory of small arms in close integration with the information processing features of small arms Doppler ballistic velocity estimation radar system. The main contents and new ideas are as follows:1. Put forward a method using fourth-order cumulants for noise reduction and the extraction of Doppler velocity which worked out the problem of bad precision by traditional frequency spectrum analysis method.Engineering realization becomes easier by simplified Recursive estimation of fourth-order cumulants.2. Bring up de-noising method based on wavelet HMM which worked out the problem of detection for low signal to noise ratio(SNR) on low stretched trajectory. Simulation experiment make it clear that wavelet package transform outgoes wavelet transform by using local signal de-noising method under the strong noise background.3. Improved on radar method and proposed a method for extraction of pill rotate speed based on wavelet analysis and improved short-time Fourier Transform method.Compared with the experimental result from nation shooting range it's clear that time-frequency analysis method based on improved short-time Fourier Transform method fits engineering requirement more which can obtain high-precision datas.4. Propose a extraction technology of projectile tracer's flight time based on wavelet analysis method.The test from nation shooting range proved that the method can make radar echo signal's characteristics unveiled.According to signal amplitude's variation signal's break point was found and the test precision meet target requirement quite well which provides evidence for national's military standard.To sum up, the paper makes deep research on small arms ballistic velocity estimation radar weak echo signal. The methods proposed by the author are of far reaching importance to the National range testing evaluation and is much worthy to be generalized and applied.