DISTANCE MEASUREMENT METHOD MAKING USE OF ELECTROMAGNETIC WAVE AND SYSTEM THEREFOR

摘要

An FM wave is transmitted to a target and its reflected wave is received A beat wave is then obtained using the thus-received wave and the FM wave. A sine wave is mixed with the beat wave and one of sideband waves of the resultant mixed wave is obtained. Another sine wave is mixed with the sideband wave. Then, one of sideband waves of the thus-obtained mixed wave is separated and detected. In the above manner, phase modulation is applied directly to the above-described beat wave. Distance-pertaining information can then be obtained from the number of peaks of the thus-modulated beat wave. A microwave profile meter suitable for use in the de-termination of the surface profile of a burden in a blast furnace is also disclosed.