Distance transducer

摘要

An electronic distance meter is interfacable to a controller and measures distance to a moving target by comparing the phase of a signal propagated to the target with the phase of the reflected signal. A time mark indicating when the measurement was made is corrected by an offset to compensate for an apparent distance error related to the doppler effect. The corrected time mark indicates when the target was actually at the apparent distance. An asynchronously resettable timer provides measurement-to-measurement elapsed time information so that position-in-time and velocity data may be obtained. A multi-valued annunciator indicates the integrity of the target signal path.