Active detection systems , such as radar and sonar , have encountered more and more threaten in modern electronic warfare and information warfare . passive location and tracking system , which uses electromagnetic wave emitted by target , has been proved its merits of self - hiding and far - distance detecting and becomes more and more important 現(xiàn)代電子戰(zhàn)和信息戰(zhàn)條件下,雷達和聲納等有源探測系統(tǒng)受到越來越多的威脅,利用目標輻射電磁信息的無源定位系統(tǒng)由于其自身隱蔽和探測距離遠等優(yōu)點而日顯重要。