Field Measurement of the Spectral Emissivity of Terrestrial Surface Materials with the Fourier Transform Infrared Spectrometer

A portable Fourier transform infrared spectrometer developed by D&P is used for the field measurement of emissivity. The method of calibration is discussed in detail, and the calibrated spectral radiance is given. A reflective plate which has low emissivity is used to measure the downwelling radiance, thus the emissivity of samples can be calculated. The method of error correction and samples of measurement results are given.