Distance measuring apparatus

摘要

Disclosed herein is a distance measuring apparatus comprising an irradiation unit for generating an electromagnetic wave, a receiving unit for receiving a reflected wave of the electromagnetic wave reflected by an object of measurement and generating a reception signal, and a propagation delay time measuring unit for measuring a propagation delay time by counting the number of pulses of a pulse train having a predetermined frequency. The propagation delay time is the time between the time that the irradiation unit irradiates the electromagnetic wave and the time that the reflected wave is received by the receiving unit. The vehicle distance measuring apparatus further comprises an electric discharge unit for performing an electric discharge from the time that the reflected wave is received by the receiving unit, a discharge-voltage measuring unit for measuring a discharge voltage of the discharge unit, and a distance computing unit for correcting the counted number of pulses, based on the propagation delay time and the measured discharge voltage, and computing a distance to the object.