Basic Study On Coherence Of The Satellite Echoes Of Laser

It often happens that the satellite echoes could not be received at our astronomical observatory. This phenomenon may be due to that the receiver does not work correctly or due to the atmospheric scattering, refraction and turbulence. In addition, the reason may be also that the receiver is in the area where light intensity is weakened by interference of different pyramids' light echoes. In order to analyze the reason for this phenomenon, we did some basic research using computer simulations, theoretical calculations and experiments. We have worked on the follows:1. The mutual coherence function (MCF) of spherical wave propagation in atmosphere was calculated, and the curve of the MCF was given.2. The phase screen was simulated and its graphical user interface (GUI) was created in the MATLAB software environment according to the theory of phase screen.3. The problem was modeled and simulated using the computer. The simulation results were compared and analyzed for different parameters.4. With the help of an electrified resistor, the effects of atmospheric turbulence were approximately simulated in the laboratory, and interference patterns affected by turbulence generated by the electrified resistor were received. The impact of the turbulence on interference of beam was studied using the interference patterns. Comparison of results between computer simulations and experiments were done. Arrival-angles were measured and distribution of arrival-angle fluctuations was given.