雷达水位计是一种非接触式的水位测量仪器,以电磁波为载波方式测量传感器到水面的距离,再通过计算得出实际的水位值。由于电磁波传播速度接近光速,近距离传输时相应的时间间隔很短,要达到cm 级的距离测量精度,时间测量的精度需要达到ps。常用的高精度时间测量方法存在价格昂贵或实现方式复杂等问题。文中介绍了一种等效采样扩时测距方式,实现在雷达水位计的测量范围内达到cm 级测量精度,并已在产品中实现了具体应用。

The radar water-level gauge, a kind of non-contact apparatus for water level measurement, measures distances between the sensor and water surface by electromagnetic wave carrier way and then calculates out actual water level numbers. Due to rate of propagation of electromagnetic wave close to speed of the light, the time interval is too short when transmission at close range. To reach centimeter-level accuracy of distance measurement, we should get picosecond accuracy of measurement time. There are some problems for common high-precision time measuring methods such as high cost and complicated implementation model. An equivalent-sampling time-spreading distance measurement is described by which centimeter-level accuracy can be realized within measuring ranges of a radar water-level gauge. That measurement method has been applied to actual products.

TN952