Infrared contrast of crude-oil-covered water surfaces

Infrared oil spill detection utilizes either temperature or emissivity contrast of native and oil-covered water surfaces. In particular, the thickness dependent radiance contrast due to thin film interference has been studied. Together with detection boundaries derived from the radiative transfer equation, we can explain historically observed daytime contrast reversal and our observations during nighttime, better contrast from thin oil slicks than from thick films, which to our knowledge has not been mentioned in the literature. These findings have important implications to long-wavelength infrared (LWIR) instrument design and data interpretation for crude oil spill detection.