| 摘要 |
The existence of an object within a predetermined range interval is detected by emitting a series of signal pulses for each range interval and detecting the echo signal pulses. First and second integrators that are respectively responsive to echo signal pulses and to noise pulses integrate the detected signals during different time intervals. The integrated signal and noise components are compared to determine their difference and an indicating pulse is generated by a level detector whenever the compared signals are greater than a predetermined value. First and second delay circuits are provided for controlling the interconnection of the integrators to the respective detectors. Third and fourth time delays respectively control the zeroizing of the integrators and the connection of the level detector to the comprising means. |
