Finding the optimum design is an iterative decision process. Every step in the design process that has conflicting needs requires a trade study. Trade studies indicate which component(s) affect acquisition range the most and the least. The variables include sensor parameters (focal length, aperture diameter, detector size, noise, and viewing distance) and scenario (target size, target/background contrast, line-of-sight jitter, atmospheric transmittance, and atmospheric turbulence). With an almost infinite number of trades possible, selecting the most important requires a priori knowledge of each parameter, the relationship to others, and its effect on acquisition range.