Impact of spectral noise shape and correlations of laser beam jitter on acquiring optical links in space.

Abstract

We investigate how the probability of acquiring an optical link between a scanning and a target spacecraft depends on the spectral shape, power, and dimensionality of the beam jitter, as well as on the choice of detector integration time, beam detection radius, and scan speed. For slow scans and long integration times, the probability of failure (Pfail) is determined by the integrated jitter power up to a critical frequency, which we verify by comparing the results of an analytical model to those of Monte Carlo simulations. Jitter above the critical frequency leads to a loss of correlation between integration windows and decreases Pfail for both 1D (radial) and 2D (radial and tangential) jitter, as long as the RMS jitter amplitude does not exceed the beam diameter. In the opposite limit of fast scans and short integration times, emergent correlations between jitter fluctuations on two adjacent scanning tracks also decrease Pfail. The analytical model is additionally used to assess the effect of multiple overlapping tracks and the impact of target drifts in the uncertainty plane.