A laser ranging method with high precision and large range in high speed based on phase measurement

In order to meet the needs of high speed, high-precision and large-range laser ranging, the analyses of the problems are discussed on both single frequency and multi-frequency laser ranging methods based on phase-shift measurement. Based on characteristics of the needs of ranging speed, precision and ranging range, the laser ranging method with phase-shift measurement is proposed based on the techniques of frequency reduction and high precision time measurement. Moreover, the method of parameters selection on ranging system is established based on the ranging needs in sequential order of the ranging frequency, time-measurement precision and reference signal frequency, and also the experimental ranging system is set up to verify the ranging method under the conditions of many fileds with high speed, high-precision and large-range laser ranging. The experiment is performed and the experimental results show that the system has a ranging range of 500 m, a ranging precision of 1.08 mm and a ranging speed of 0.03-0.04 s under the conditions of a 300 kHz ranging signal of modulation, a 260 kHz reference signal and a time-measurement precision of 50 ps. The experiment verifies the effectiveness of the ranging method and system, which can lay the foundations for the high speed, high-precision and large-range ranging. ©, 2015, Board of Optronics Lasers. All right reserved.