- Many of the standard considerations for the modeling of infrared target acquisition of stationary targets in a single field of view must be altered when considering target acquisition in the actual battlefield. Sensors are scanning, targets are moving, and a complex background is present. A metric is needed to determine acquisition efficacy which is considerably more complex than the standard analysis. In this paper, we will discuss several of the issues involved. The use of a single detectable frequency to model the target acquisition process is not sufficient. We consider the replacement of this model with one consisting of an integral of the target spectrum, taking into account the spatial frequency modulation transfer function dependence of the imaging system. Psychophysical experiments are presented; the results of this experiment verify our approach that the maximum spatial frequency criterion is not sufficient to determine the target acquisition probability.