A new technique developed at General Dynamics Convair Division permits rapid calculation of sensor performance including full statistical treatment of atmospheric and target conditions. The most common statistical method in use relies on the Monte Carlo technique in which thousands of single point calculations are made with data from a random number generator. The Monte Carlo method is replaced by a closed form calculation requiring orders of magnitude less computer time. The probability density function of atmospheric attenuation is used along with the appropriate distribution of target characteristics. The probability density function of the video signal-to-noise ratio is calculated directly using simple numerical integration. Performance criteria can then be applied to the curve for either observer or autonomous operation. Sample results are presented of FLIR and laser 3-D imager performance against targets in European atmospheric conditions.