Calibration and Characterization of Satellite‐Borne Microwave Sounders With the Moon

Burgdorf, M.; Buehler, Stefan A.; Prange, Marc

doi:10.1029/2021ea001725

Cited by 3 publications

(1 citation statement)

References 26 publications

(82 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to the random scatter of observed brightness temperatures, which is the basis for the error bars in Figure 3, Burgdorf et al (2021) had found a positive bias of 5.5% in the disk-integrated flux density of the Moon as measured with MHS when compared to the model by Liu & Jin (2021a). Therefore, we have divided the flux densities at 89 GHz from AMSU-B by 1.055.…”

Section: Systematic Discrepancies Between Model and Observationmentioning

confidence: 98%

Observation of a Lunar Eclipse at 89, 150, and 183 GHz

et al. 2023

View full text Add to dashboard Cite

We describe the measurement of the brightness temperature of the Moon from space during a total lunar eclipse by using a microwave sounder aboard a weather satellite. Previous observations of lunar eclipses were inconsistent and did not cover the frequency range between 100 and 200 GHz. In this work, we seek to establish a reliable relationship between frequency and drop in brightness temperature during a total eclipse for millimeter wavelengths. For this purpose, we chose the eclipse on 2004 October 28, because it coincided with appearances of the Moon in the deep space view of the Advanced Microwave Sounding Unit-B on NOAA-15. It was therefore possible to measure its disk-integrated radiance at 89, 150, and 183 GHz at 100 minutes intervals. Our observations are, to the best of our knowledge, the only ones between 100 and 200 GHz, and demonstrate the nearly linear dependency on frequency of the maximum relative drop in effective temperature during an eclipse. The slope of this function is m = 0.00114 ± 0.00017 GHz−1 in the range 88–300 GHz. The good agreement between the variations of the effective lunar temperature and a new radiative-transfer model suggests that the Moon is suitable as a flux standard for microwave observations with beam sizes larger than 0.5°.

show abstract

Section: Systematic Discrepancies Between Model and Observationmentioning

confidence: 98%

Observation of a Lunar Eclipse at 89, 150, and 183 GHz

et al. 2023

View full text Add to dashboard Cite

show abstract

Disk-resolved and disk-integrated polarization state of moonlight as a function of lunar phase

Venkatesulu,

Dabby,

Shaw

2023

Polarization Science and Remote Sensing XI

View full text Add to dashboard Cite

To use moonlight as a source for on-orbit calibration of satellite instruments and for nighttime passive remote sensing, considerable effort has been made to develop and improve radiometric models of the Moon. However, to enable calibration of polarization-sensitive instruments and nighttime polarimetric remote sensing, the polarization state of moonlight must be known as well. While several observations of moonlight polarization have been published, there is no known database of disk-integrated polarization measurements or disk-resolved polarization images as a function of phase angle. We used a monochrome division-of-focal-plane polarization imager with a telescope (focal length of 2 m) and a telephoto lens (focal length of 300 mm) to record images of the degree and angle of linear polarization for lunar phases ranging from full Moon to about 15% full. We calculated the disk-integrated polarization state from the images. We present a plot of disk-integrated polarization state as a function of phase angle, which agrees well with similar plots published previously for small regions of the Moon. The disk-integrated degree of linear polarization (DoLP) reaches a maximum of approximately 8% at a phase angle near 100° and a minimum near 0% at a phase angle of 0°. We also present S0, DoLP, and angle of polarization (AoP) images and use them to explain the lunar locations where polarized light primarily originates. To our knowledge, the presented DoLP images are higher resolution than previously published DoLP images, and AoP images presented here have not yet been published.

show abstract

Polarization images of the Moon as a function of the lunar phase

Venkatesulu,

Shaw

2024

Opt. Express

View full text Add to dashboard Cite

Moonlight has a partial polarization state that varies with the lunar phase angle. This needs to be characterized for the Moon to be used as a calibration source for polarization-sensitive instruments or as the illumination source in nighttime passive remote sensing. To contribute to this characterization, a pixelated polarization imager was calibrated with a telescope and with a telephoto lens and used to record images of the Moon at 40 phase angles from -138° to 125°. High-resolution images of relative intensity, degree of linear polarization (DoLP), and angle of polarization (AoP) were recorded in a spectral band from 400-1000 nm and were used to calculate disk-averaged DoLP values. These images are made available to readers. Results showed higher DoLP in regions of lower reflectivity (the Umov effect), higher DoLP for waning phases (maximum DoLP of 8.3%) than for waxing (maximum DoLP of 6.8%), and consistent DoLP to disk-averaged values published previously for wavelengths contained within our broader band.

show abstract

Calibration and Characterization of Satellite‐Borne Microwave Sounders With the Moon

Abstract: The quasi-optical components of microwave sounders were characterized with ap-7 pearances of the Moon. 8• The disk-integrated brightness temperature of the Moon was measured for per-9 ihelion and aphelion. 10• Two different models of the lunar radiance were put to the test.

Cited by 3 publications

References 26 publications

Observation of a Lunar Eclipse at 89, 150, and 183 GHz

Observation of a Lunar Eclipse at 89, 150, and 183 GHz

Disk-resolved and disk-integrated polarization state of moonlight as a function of lunar phase

Polarization images of the Moon as a function of the lunar phase

Contact Info

Product

Resources

About