公开(公告)号：US5689268A

公开(公告)日：1997-11-18

申请号：US691729

申请日：1996-08-02

申请人： Nai K. Shi ,  Henry F. Williams

发明人： Nai K. Shi ,  Henry F. Williams

IPC分类号： G01S7/41 ,  G01S13/52

CPC分类号： G01S7/415

摘要： The blade flash signature in a radar return is enhanced and used to detect and classify helicopter targets. The radar return of a target is fast Fourier transformed 34, and the frequencies corresponding to DC and the body of the target are filtered out 38. The filtered signal is inverse transformed 44, moving averaged 52, and auto-correlated 54. Auto-correlation 54 may take place in the frequency domain. If there are significant peaks in the auto-correlation output (other than at zero time delay), then a helicopter is present. The time delay between peaks is the period of the blade. The height of the peak indicates whether it is the main blade or the tail blade which has been detected, and allows a signal indicating both periods to be output. The main blade period and the ratio of the period to that of the tail blade can be compared with a data base to classify the helicopter.

摘要翻译： 雷达回波中的闪光灯签名被增强，用于检测和分类直升机目标。 目标的雷达返回是快速傅立叶变换34，并且对应于DC和目标身体的频率被滤除38.滤波的信号被逆变换44，移动平均52和自相关54.自相关 54可能在频域中发生。 如果在自相关输出中有明显的峰值（除了零时间延迟），则存在直升机。 峰值之间的时间延迟是叶片的周期。 峰值的高度表示是否已经被检测到的主叶片或尾叶片，并且允许指示两个周期的信号被输出。 可以将主叶片期间和尾桨的周期与数据库进行比较，对直升机进行分类。