Accuracy of Gaussian approximation for simulating EO sensor response

The method chosen for simulating an electro-optical sensor response function (SRF) has an appreciable affect on the time required for Monte Carlo simulations of kinetic kill and surveillance missions. A particularly efficient SRF model is a circularly symmetric gaussian surface. This paper shows that for on-axis optics circularly symmetric gaussian surfaces are close representations of SRFs. Approximation errors are shown to be less than the sensor rms noise for an approximation centered on the optical axis and one 2.12 degrees off the axis for signal-to-noise ratios (SNRs) of 43.5 and 12.6, respectively.