Round-trip turbulence ladar scintillation modeling using data fits and resulting signal-to-noise ratio

摘要

The signal-to-noise power ratio parameter of coherent ladar systems operating within the atmosphere and including atmospheric scintillation effects is modeled. Previously published round-trip geometry ladar data of the variance of the normalized-irradiance as a function of the one-way path integral Rytov parameter are utilized to estimate a signal-to-noise power ratio. However, these data were taken in the strong signal case where local-oscillator-laser noise was negligible. A model is proposed to combine the local-oscillator-laser produced noise, a zero-mean wideband-Gaussian random process corresponding to normal coherent ladar operation, with the scintillation produced by round-trip turbulence based on a calculation of the one-way path-integral Rytov parameter. Close agreement with Shapiro's 1981 analysis is found, provided one modifies the Shapiro formulation to account for scintillation saturation.