There are a large number of EO and IR sensors used on military platforms including ground vehicle, low altitude air vehicle, high altitude air vehicle and satellite systems. Ground vehicle and low altitude air vehicle (rotary an fixed wing aircraft) sensors typically use the probabilities of discrimination(detection, recognition, and identification) as design requirements and system performance indicators. High altitude air vehicles and satellite sensors have traditionally used the National Imagery Interpretation Rating Systems (NIIRS) performance measures for guidance in design and/or measures of systems performance. Data from the high altitude air vehicle and satellite sensors is now being made available to the warfighter for many applications including surveillance and targeting. National imagery offices are being merged and restructured to more fully support warfighters and connectivities to high altitude air vehicle sensors. It is becoming more apparent that the gap between the NIIRS approach and the probabilities of discrimination approach will have to be addressed. Users, engineers, and analysts need to have a comparative basis for assessing the image quality between the two classes of sensors. This paper describes and compares the two approaches.