Electrooptical System Evaluation
Electrooptical imaging devices such as image intensifiers and low-lightlevel tv systems are generally used to acquire and recognize objects of one type or another under conditions of low illumination. A realistic evaluation of these devices requires determining to what extent they aid an observer in this endeavor. Unfortunately, prediction of the search performance of human observers employing various electrooptical imaging devices is a rather complex task which has not yet been adequately handled. However, it is still reasonable to examine the search problem and to attempt to formulate an approximate model to predict search behavior. A model can provide not only a measure of the relative value of various devices, but also the knowledge necessary to determine the relative value of changes to the design and construction of the device. Any attempt to evaluate electrooptical devices employing a technique that does not treat the search process quantitatively is insufficient. Search performance must in general be weighed against numerous other device characteristics, e.g., cost, weight, size, complexity, etc., in order to select that device which can best perform any specific task; this weighing requires quantitative knowledge of the relative search effectiveness of devices. Therefore, in this chapter, a search model is formulated that can be used to evaluate electrooptical devices. Two simple systems are then examined using this model. Even though the model constructed is approximate and of limited applicability, the techniques used to develop this model are valid and can be employed to formulate more exact and more broadly applicable models as required.
KeywordsPower Spectrum Flux Distribution Shot Noise Image Intensifier Image Tube
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