The Moon as a Proposed Radiometric Standard for Microwave and Infrared Observations of Extended Sources

Abstract

Measured values of the average midnight and morning terminator infrared brightness temperatures of the central portion of the lunar disk can quite accurately determine the mean surface temperature despite likely horizontal and vertical inhomogeneities of the thermal properties of the lunar soil. These data together with laboratory measurements on lunar soil and in situ temperature measurements in and on the lunar surface lead to a mean surface temperature of 220.5° K ± 2.5 percent and a mean temperature 35° K hotter at a depth of 1 m. The monthly average brightness temperature is then estimated as a function of wavelength between 10 ^m and 100 cm taking into account likely temperature dependencies of the thermal conductivity and loss tangent, and the variation of emissivity with wavelength. The accuracy with which the Moon can be used as an absolute radiometric standard for extended sources is estimated based on the likely range of lunar thermal and electromagnetic properties. Subject headings: infrared-Moon-radio radiation-radio radiation, planetary

Using lunar observations to assess Terra MODIS thermal emissive bands calibration

“…It needs, however, to be considered for the bands at relatively short wavelengths, such as band 21. In order to use Equations 3 and 4 for band 21 calibration, the following steps should be implemented: The first step is straight forward as the lunar emissivity at band 31wavelength can be found from the literature and its solar reflectance term can be ignored [12][13][14] . To derive the lunar emissivity at the wavelength of band 21, a best fit between band 31 and band 21 spectral radiances from the moon (which depend on lunar emissivity) and to that from the onboard BB is performed.…”

Lunar thermal emission and remote determination of surface properties

“…Typically, it is of the order of 3.5 m for basalt. Rocks as small as I m will not be able to conduct all of their stored heat into the regolith [Linsky, 1973;Buhl, 1971;Roelof, 1968]. Not surprisingly, rocks show a different behavior in laboratory measurements of their thermal conductivity than do fines.…”

Calibration of planetary brightness temperature spectra at near-millimeter and submillimeter wavelengths with a Fourier-transform spectrometer

“…The ratio 3Eq. 11324 of the full Moon's antenna temperature to its maximum physical temperature when full, 29,30 390 K, then provides h c 1n2 for the Moon, hereafter h moon 1n2, which is the desired integral of P n 1V2 over both the main and the error beams. Thus division of a planetary spectrum by that of the Moon 1both already in T* A units2 corrects for the efficiency loss that is due to the wide-angle contribution, leaving only the coupling to the main and the error beams to consider.…”