Research On Unintentional Interference Suppression And Target Tracking Algorithm Of Airborne Early Warning Radar

Airborne early warning radar have unique advantages in detecting enemy air targets over ground warning radar.Therefore,it plays a very important role in modern warfare.In recent years,with the continuous development of electronic countermeasure technology and equipment,the electromagnetic environment faced by airborne early warning radar has become increasingly complex.Radar systems not only affected by ground(sea)clutter,but also faced with the threat of various electromagnetic interference.The existence of clutter and interference seriously affects the target detection performance,and also makes it difficult for radar to estimate the parameters of targets and track them.In the field of airborne radar signal processing,although space-time adaptive processing(STAP)technology can be used to obtain a certain degree of clutter and interference suppression capabilities,due to the rapid change of the interference environment,it is difficult to rely on STAP technology to ensure Gain an advantage in electronic countermeasures.In the case of a large number of interferences,interference suppression will consume STAP’s degree of the freedom and reduce the system’s clutter suppression capability.Therefore,in order to improve the target detection performance of airborne radar,it is of great significance to carry out research on other signal processing techniques of interference suppression.On the other hand,in the field of radar data processing,multi-target tracking has been one of the hot research topics both here and abroad because of its prominent position and wide application in the military and civilian fields.Several problems that often appear in multi-target tracking have not been solved well,such as large amount of calculation and incorrect data association.This paper focuses on the research of airborne radar unintentional interference suppression techniques and multi-target tracking algorithms.Through research,different types of interference detection and suppression methods,dense interference suppression technology and airborne radar multi-target tracking algorithms are obtained.Thesis work mainly includes:1.Unintentional interference detection methods are studied.Based on the in-depth analysis of narrow band continuous wave interference and asynchronous short pulse interference,the interference signal models are established.According to the difference in the time and frequency domain between interference and echo signals,three algorithms are studied.For narrow band interference,a two-dimensional frequency domain detection algorithm is given.For asynchronous interference,a detection method based on the radar echo data before pulse compression and a singular value detection method based on pulse cancellation are studied.Simulation and measured data processing verify that the proposed method can detect interference well,which lays a foundation for subsequent interference suppression research.2.This thesis studies the topic of dense unintentional interference suppression based on airborne radar.For narrow-band interference,frequency-domain notch algorithm and sub-space projection algorithm are studied.The performance of the two algorithms is evaluated in terms of interference suppression effect and target signal loss.Aiming at asynchronous interference,two different interference suppression algorithms are proposed.They are time-domain notch algorithm and asynchronous pulse elimination algorithm.Considering the ambiguity of singular pulse caused by pulse cancellation processing in the second method,a singular pulse location method is proposed,which can solve this problem well.The effectiveness of the above methods is verified by measured data processing.finally,a complete dense unintentional interference suppression technology is designed to solve the problem that the above methods cannot effectively suppress two types of unintentional interference at the same time.Measured data processing results prove that the proposed technology can suppress interference effectively.3.Research on multi-target tracking theory.Focusing on the analysis of three common data association algorithms based on Bayes theory.Considering the contradiction between the real-time performance and accuracy is difficult to reconcile in multi-target tracking,an improved JPDA algorithm is proposed.Reducing the complexity,while the tracking accuracy is ensured.In addition,this algorithm improved tracking performance of neighboring targets.Through simulation experiments,the effectiveness of the improved algorithm is verified.