ABSTRACT

This chapter outlines the imaging sensor simulation, tailored for systems that use time-delay-and-integrate charge-coupled device focal planes. The digital simulation process can be broken down into three main functional processes: computation of the two-dimensional modulation transfer function (MTF), sensor signal chain analysis, and digital signal processing; Fourier filtering to simulate the spatial blurring process; and display of the simulated imagery. The imaging performance of visible scanning image sensors that employ silicon solid-state imaging focal plane devices is generally described in terms of some measure of resolving capability, which in turn is determined by the combined effects of the input scene image modulation, system MTF, and single-pixel signal-to-noise ratio. The magnitude and spectral content of the irradiance in the focused image depend on sensor design and system operating parameters. The main contributor to reduction in MTF due to the intervening atmosphere is turbulence.