| 摘要 |
<p>A value of signal level of reflected wave for transmitting a target sensing signal is modified according to a distance to a target as a threshold level, which is set in advance. By recognizing a phase difference of reflected waves from the target and a signal level of the reflected wave from the target, correct one of the distances to two objects caused by a return error which are obtained only by the phase difference is selected according to the signal level of the reflected wave.</p> |
