| 摘要 |
Complicated range gate radar systems are known for determining distance to a target, the target sometimes being centered in the range gate which may have a predetermined width equivalent to a predetermined distance. For example, the range gate may extend from 10,000 to 11,000 yards. The present invention provides a new and simple system for determining range to a target. A series of pulses of energy capable of being reflected from a target is transmitted. Consecutive pulses in the series are spaced apart in time by a predetermined interval and echo-pulses from the target are listened for for a time after each of a plurality of the transmitted pulses. The listening time for consecutive transmitted pulses is varied in a substantially linear manner from substantially zero to a maximum time less than the predetermined interval between transmitted pulses. The transmitted pulses are counted from the beginning of the measurement interval. When an echo is received, counting is stopped and the number of pulses counted is proportional to the distance to the target.
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