Research on atmospheric coherence length detection method based on optical computing lidar

The atmospheric coherence length is an important parameter that reflects the turbulence effects on optical wave transmission through the atmosphere. Real-time acquisition of atmospheric coherence length plays a significant role in various fields. Utilizing DIM lidar, we integrated related imaging and lidar technologies, substituting high quantum efficiency array detectors with optical modulators and APD detectors. We then conducted research on atmospheric coherence length detection using optical computing lidar. Through the laser atmospheric turbulence phase screen transmission program, we conducted numerical simulations of the centroid jitter variance in non-imaging optical computing methods, which demonstrated good consistency with results calculated by conventional methods. The system structure and technical specifications of the independently developed optical computing lidar are introduced. Experiments on the high spatial-temporal distribution of atmospheric coherence length were conducted in Hefei during summer nights at multiple angles (15°, 30°, 45°, and 90°). Preliminary results indicate that the atmospheric coherence length near the ground diminishes gradually with increasing detection distance, up to 4.5 km. The numerical range observed is between 4 to 9 cm, suggesting that employing optical computing lidar to detect atmospheric coherence length is both feasible and reliable.