“Researchers have made significant progress in the field of free space optical communication between space and Earth. To address the issue of advance angle in the system, they proposed a novel wavefront detection technique based on light intensity transmission called Projection Pupil Profile (PPPP). This technology uses the TIE light intensity transmission formula to analyze the changes of light intensity distribution at different transmission distances, and can inverse solve the wavefront distortion caused by atmospheric turbulence. The experimental results show that PPPP technology uses the backward Rayleigh scattering of the uplink communication laser itself, and its measured atmospheric turbulence direction is consistent with the direction of the communication satellite, thus effectively solving the problem of advance angle in satellite ground laser communication. The experiment simulated a 1-meter ground-based telescope as an upward laser emitting device and a backscatter spot imaging device, and achieved wavefront detection of atmospheric turbulence below 10 kilometers through images of upward laser backscatter spots with equivalent heights of 10 kilometers and 17 kilometers, respectively. Compared with traditional Shack Hartmann wavefront detectors, PPPP technology can achieve similar wavefront reconstruction effects, and the residual of the reconstructed phase between the two is about 30% of the initial phase. This research achievement provides an effective solution to the problem of advance angle in satellite ground free space optical communication systems, opens up new directions for research in related fields, and lays a solid foundation for the future development of satellite ground laser communication technology.”