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公开(公告)号:US5081459A
公开(公告)日:1992-01-14
申请号:US614135
申请日:1990-11-16
IPC分类号: G01S13/52 , G01S7/292 , G01S7/41 , G01S13/524
CPC分类号: G01S7/415 , G01S13/5246
摘要: This Doppler radar for the detection and localization of helicopters through blade flashes works in a band located between 300 MHz and 20 GHz and identifies the blade flashes by the width of their frequency spectrum and their duration. It uses, at reception, a multilobe antenna associated with several parallel signal processing chains specialized in the detection of helicopters, enabling detection over a widened zone as well as precise localization. Each chain has a phase amplitude detector PAD (10, 10') followed by a Doppler filter MTI (20, 20') selecting the wide frequency spectrum, a module computing circuit (30, 30'), a contrast circuit (40, 40') eliminating excessively long echoes, a threshold circuit (50, 50') and a false alarm reduction circuit FAR (60, 60') eliminating excessively short echoes. The chains lead to a relative bearing computation circuit (100) performing angle measurements when this is possible.
摘要翻译: 这种用于通过叶片闪光检测和定位直升机的多普勒雷达在位于300MHz和20GHz之间的频带中工作,并且通过其频谱的宽度及其持续时间来识别叶片闪烁。 它在接收时使用与多个并行信号处理链相关联的多叶天线,专门用于检测直升机,使得能够在加宽区域上进行检测以及精确定位。 每个链具有相位幅度检测器PAD(10,10'),随后是选择宽频谱的多普勒滤波器MTI(20,20'),模块计算电路(30,30'),对比电路(40,40) ')消除过长的回波,阈值电路(50,50')和消除过短的回波的假警报降低电路FAR(60,60')。 当可能时,这些链通过执行角度测量的相对轴承计算电路(100)。