Research On Coherent TBD Algorithm For Weak Targets With High Speed

With the development and application of stealth technology, the RCS of military targets such as warships, fighter planes and missiles have reduced greatly and the SNR of the radar echo have been decreased drastically, resulting in rapid lowering of the probability of target detection and posing a great challenge to radar detection. So the effectiveness of weak target detection is of great importance in the development of modern radar technology. Firstly, this dissertation studies the basic theoretical knowledge of weak target detection, and on the basis of in-depth study related theory of weak target detection, the current methods used to improve SNR are analyzed, such as the clutter suppression technology, integration for a long time and walking distance compensation technology. Then advantages of Track-Before-Detect(TBD) over Detect-Before-Track are analyzed. Then two TBD algorithms based on the noncoherent integration are introduced, TBD algorithm based on Hough transform and dynamic programming, and this dissertation introduces the basic principle and realization method of the two algorithms, and the effectiveness of weak target detection through computer simulations is verified, and then the problems of the two algorithms are also analyzed. Traditional TBD algorithm across multiple frame echos using non-coherent energy integration cause some loss of integration. Next, this dissertation analyzes the great advantage of coherent algorithm based on multiple frame data over the traditional algorithm for weak target detection. Then this dissertation mainly studies the four kinds of TBD algorithm based on multiple frame coherence: multiple frame coherent TBD algorithm based on time domain, frequency domain, envelope interpolation displacement and the keystone transform. Target motion model and echo signal model based on coherent TBD algorithm are presented. And then basic principle implementation method and steps are introduced. Through the computer simulations for the four coherent TBD algorithms, the effectiveness of the four coherent TBD algorithms for weak target detection is verified and the analysis and comparison of the performance of the four algorithms are given.