Pointing and tracking errors due to low-frequency deformation in inter-satellite laser communication

ABSTRACTA Gaussian random-phase screen (GRPS) model is proposed to represent the low-frequency wave-front deformation in inter-satellite laser-communication links. The model is used to investigate mutual-alignment errors comprising pointing and tracking errors caused by the low-frequency deformation. Theoretical analysis and numerical simulation show that the GRPS root-mean-square (RMS) value, pointing error, and tracking error increase with the amplitude factor a and the scale length sg in the model. The expectation of RMS increases in the form of a linear function with a and increases in the form of a cubic function with sg. The expectations of the pointing and tracking errors increase with increases in the expected values for a and sg. For a specific pointing error or tracking error, the 99.5% confidence interval of the RMS of the low-frequency wave-front deformation is provided. From this confidence interval, the lower limit of the processing precision of optical antennas corresponding to certain mutu...