Laser ranging technology detects the target by emitting active laser signals, receives the echo signal diffusely reflected by the target and performs statistics, processing and conversion to obtain the distance and speed information of the target. Realize the detection of target distance information, with its simple system, flexible operation, high precision and other characteristics, it is widely used in various occasions such as civil, scientific research and military; laser ranging system based on photon counting technology, in pulsed laser measuring In terms of distance, the introduction of time-correlated single photon counting technology reduces the requirements for laser pulse energy and power consumption, improves the effective ranging range of the system, and improves the time resolution accuracy and detection accuracy of the system. Compared with traditional light sources, laser has the characteristics of good monochromaticity, small divergence angle and good coherence. Using laser as an active detection light source will make the ranging accuracy higher, the distance longer and the reliability better.
1. Laser ranging principle
The laser ranging method is roughly divided into phase method and time-of-flight ranging method. The phase method has high precision, but the processing system is complex, resulting in a long time for data processing; while the processing circuit of time-of-flight is simple, and due to the time measurement components It can also achieve high-precision measurement and can be used for long-distance ranging. In this lecture, the multi-pulse cycle conformance long-distance ranging based on single photon detection is mainly realized through FPGA.
The pulse time-of-flight ranging method is used in the experiment. The principle of the time-of-flight ranging method is simple. It only needs to measure the time interval between the transmitted signal and the echo signal to calculate the distance. The formula is as follows: