Pulse Doppler Radar For A Long Time Accumulation Of Technical Studies

In recent years, with the stealth aircraft's official service, the radar is meetting a serious existing crisis and the national security is also facing a tremendous threat. How to improve the radar's performance to detect stealth target becomes an extremely important and severe mission.Pulse-Doppler radar has been widely used in the early-warning especially in the airborne early warning with its good performance in detecting moving targets in clutter. But there are serious deficiencies in detecting stealth aircraft for conventional Pulse-Doppler radar. An effective method to improve Pulse-Doppler radar's anti-stealth ability is long-time integration. The dissertation supported by a project foucses on long-time integration technology of Pulse-Doppler radar.Its main contents includes:Research background,meaning and the status quo at home and abroad of long-time integration technology was introdued in chapter one.The basic theory of signal processing in Pulse-Doppler radar was introdued systematically in chapter two.The LFM signal the pulse compression was introduced firstly .The principle of moving target detecting and coherent integrating with Doppler filters was analyzed secondly.Envelope migration of radial target with Constant speed under the condition of long-time integration was studied in chapter three.Fistly, the problem that envelope migration will cause target's energy scattered in different range gates further affect the performance of long-time integration was pointed by analyzing the feature of ehco. Then two conventional envelope migration compensation algorithm was introduced , on this basis, a new algorithm called frequency domain correction was proposed. Finally the algorithms' operation amount were analyzed and the result showed that the new algorithm's operation amount was lower than other algorithms.Envelope migration of radial target with constant acceleration was researched in chapter four. A problem that there are not only once migration but quadratic migration in envelope migration which will cause conventional algorithms' performance degradated was pointed by analyzing the feature of ehco. A new method which using two order keystone transform to correct quadratic migration and frequency domain correction to correct once migration was proposed.Doppler migration was studied in chapter five.The reason of Doppler migration and the restraint of conventional Doppler filter were analyzed firstly.Then Wigner-Hough transform was proposed to compensate Doppler migration.