Broadband and Spectral Emissivities (2–18 μm) of Some Natural Soils and Vegetation

Broadband and spectral emissivities of several soil types, grass and tree leaves are reported for wavelengths between 2 and 18 μm. Broadband measurements were made in situ with an 8–14 μm bandpass radiometer, and spectral measurements were made in the laboratory with a dual beam Fourier transform spectrometer. Broadband emissivity was nominally 0.89–0.92 for sands, 0.96 for clay, and 0.97–0.99 for peat, muck and grass. The emissivity spectra indicated near-greybody behavior for vegetation but marked departures near 9–10 μm for the sands.