| 主权项 |
1. A measurement apparatus measuring a flight time of a search wave corresponding to a time after the search wave is emitted and before a reflected wave of the search wave is received, the measurement apparatus comprising:
a transceiver emitting the search wave, receiving the reflected wave, and outputting a receiving signal; a memory portion; a sampling portion generating a sampling data of the receiving signal and causing the memory portion to store the sampling data, wherein the sampling portion includes
a first processing unit causing the memory portion to store the sampling data generated by sampling the receiving signal at a first sampling frequency as a first signal data, anda second processing unit causing the memory portion to store the sampling data generated by sampling the receiving signal at a second sampling frequency, which is lower than the first sampling frequency, as a second signal data; a measurement portion measuring the flight time based on the first signal data and the second signal data and generating a measurement value of the flight time; and a determination portion determining a sampling period of the receiving signal corresponding to the first signal data based on the measurement value of the flight time, wherein the first processing unit causes the memory portion to selectively store the sampling data of the receiving signal in a specific period with an emission event of the search wave as a reference, as the first signal data, and the specific period corresponds to the sampling period determined by the determination portion. |
