Vol. 13, issue 11, article # 7

Abstract:

We present a comparison among three techniques for calculating the spectral emissivity of specularly reflecting plane surfaces using narrowband IR radiometric data. Relations are given to calculate the spectral emissivity as well as the instrumental errors and the errors due to the methodology used. The first method is suitable for field measurements of the spectral emissivity of natural objects, including thin films on the water surface; and its accuracy is higher than 0.005 when the radiometer noise level is about 0.1°. By selecting most appropriate method, the accuracy of the spectral emissivity measurement can be made as small as from 0.0015 to 0.004 at the noise level about 0.1°.