| 摘要 |
PURPOSE:To detect a multi-degree echo by detecting the multi-degree echo at long distance where no unnecessary echo is mixed. CONSTITUTION:One specific or plural succeeding bits are transmitted and received in every elevation step at a longer transmission repetition period than other hits. Namely, a multi-degree detector 20 quantizes and detects a video by a slicer 21 with a prescribed threshold value in the time zone of the period extension part of the output video of a transmitter receiver 10. Then, the quantized video outputted by the slicer 21 is shaped by a removal pulse generating circuit 22 to generate a removal pulse. A multi-degree echo removing device 30, on the other hand, delays the output video of the transmitter receiver 10 by a delay circuit 31 corresponding to the transmission repetitive period and a gate circuit 32 removes the multi-degree echo stably with the removal pulse outputted by the multi-degree echo detector 22, so that the wrong removal of a primary echo is reduced.
|
