RANGE FINDER, SHAPE MEASURING DEVICE, AND METHODS FOR THEM

摘要

A range finder using a spread-spectrum radar for measuring a distance with high precision at low cost. The range finder includes a transmitting unit (71) for radiating a transmission wave (75) the spectrum of which is spread with a code having a constant chip rate, a receiving unit (72) for receiving a reflected wave (76), a correlation unit (73) for calculating the correlation waveform representing the relation between the correlation between the transmission wave (75) and the reflected wave (76) and the delay time, and a distance calculating unit (74) for calculating the distance to an object by using the peak position of the correlation waveform. The correlation unit (73) calculates the correlation waveform of when the delay time is varied for each range gate which is the time length corresponding to the chip rate. The distance calculating unit (74) calculates the delay time corresponding to the peak of the correlation waveform with a resolution smaller than the range gate by using the point indicating the highest correlation and the point indicating the higher correlation out of the two adjacent points before and after the point thereby calculating the distance to the object.