Wavelength optimization for passive ranging through the atmosphere

The ability for passive electro-optical sensors to provide simultaneous target angle and range data could substantially enhance system performance in many applications. This paper evaluates a technique where the sensor monitors two or more wavelengths of the target signal and the differential attenuation through the intervening atmosphere is used to calculate target range. In particular, effects of wavelength, bandwidths, and molecular absorption characteristics on the accuracy of target range determination are assessed.