Infrared Observations Of the Eclipsed Moon from Space


	The eclipse was observed on three data collection events (DCEs) spaced about 50 minutes apart. Each 20 minute DCE obtained ten 6° long raster scans at a scan rate of 0.05°/sec. The satellite was stepped 0.05° in cross scan at the end of each raster leg while the dark offset was being measured with the internal shutter closed.
	The Moon was scanned near the beginning of the odd numbered scans and the end of the even numbered scans. Thus, successive scans across the Moon were alternately spaced by about 3 and 1 minute apart. Only about two-thirds of the Moon was within the field of view of the two near infrared arrays on each scan. Therefore, the first scan was oriented such that the edge of the Moon is just within the outer edge of the array and successive raster legs were offset by 0.05° in the cross-scan direction. Thus, the Moon was walked across each sub-array during the DCE. The observations were converted into brightness temperatures, mapped onto a flat plane projection with 6” spacing and selenographic coordinates assigned to each grid element. The positional accuracy of the result was roughly 0.5° and 1.0° in selenographic latitude and longitude, respectively, which is consistent with the resolution of the observations and the pointing accuracy of the system. The formal 5% uncertainty in the radiance calibration translates to a ~1K uncertainty in the brightness temperature.
	Above is a montage of images from all three DCEs, in which the data from two successive legs were combined. The data do not overlap owing to the 0.2° gap caused by the focal plane mask separating the two 4.3 µm spectral bands. The narrower black line is due to a group of dead detectors in one of the bands.