Data Set Information
DATA_SET_NAME MSX LUNAR ECLIPSE OBSERVATION V1.0
DATA_SET_ID MSX-L-SPIRIT3-2/4-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : As part of the Midcourse Space Experiment (MSX), the Spatial Infrared Imaging Telescope (Spirit III) observed the lunar eclipse of September 27, 1996 with 30 arcsecond resolution. This data set consists of three FITS image cubes corresponding to three data collection events about 50 minutes apart, during which the eclipse was observed for a duration of approximately 20 minutes each time. The data are stored in each image cube as two bands, A and B, each consisting of six planes. Band B data were acquired in two narrow spectral bands (FWHM : 4.22 to 4.36 and 4.24 to 4.45 microns), converted to brightness temperatures in Kelvin, and then co-added to produce brightness temperature maps centered at 4.3 microns. Band A consists of qualitative (uncalibrated) data from 6.8 to 10.8 microns, with an effective wavelength of 8.3 microns. The file names reflect the naming convention from the various observations that MSX performed. In this case, the observations were made in a calibration program in which all were designated 'DC.' '35' indicates the specific subprogram involved, and '02' - '04' are the Data Collection Event (DCE) numbers for the lunar eclipse set of observations. Hence the files are DC3502, DC3503, and DC3504. Additional details of MSX and the SPIRIT III instrument can be found on pages 3-4 of the accompanying presentation (Price_Eclipsed_Moon.pdf/Price_Eclipsed_Moon.htm in the 'doc' folder). Page numbers given in this overview refer to that presentation (which should be viewed with the 'notesview' option). Further information on other astronomy experiments by MSX can also be found in Price et al. (2001); discussion of the calibration can be found in Price et al. (2004). Each DCE consisted of ten 6 degree long legs (raster scans), in inertial coordinates of the Moon, and lasted 24 minutes (see page 6). The scan rate was 0.05 degrees per second, and roughly two- thirds of the Moon was in the field of view of the arrays on each scan. The Moon was within the field of view near the end of the even numbered legs and near the beginning of the odd numbered legs. Due to the scan rate, length, and geometry, the time intervals between complete scans were 3 min, 1 min, 3 min, etc. Therefore, data from even- and odd-numbered legs were co-added to fill data gaps, thereby reducing the ten legs to six segments. Segment 1 is the data from leg 1, Segment 2 is the data from legs 2 and 3, Segment 3 is the data from legs 4 and 5, Segment 4 is the data from legs 6 and 7, Segment 5 is the data from legs 8 and 9, and Segment 6 is the data from leg 10. Note that this is slightly different from the averaging done for the presentation (page 6), in which the scans were simply paired 1 & 2, 3 & 4, etc. The remaining data 'dropouts' are a combination of the filter mask that separates the two 4.3 micron bands on the focal plane array and a group of dead detectors (which show up as lines due to the scanning). The spatial resolution is 45 km or 1.5 degrees in selenographic coordinates at the center of the lunar disk. Off-moon data values are representative of the system and processing noise (for best results in viewing image planes, limit the data values to >0). The uncertainty in the derived temperatures is ~1 K (see pages 5-6). The 8.3 micron data (band A) are all in at least soft saturation and thus could not be calibrated. The worst areas went into hard saturation and those data were set to 0. Also, in DC3504, band B went into saturation as the Moon came out of eclipse, which affected portions of the still-eclipsed Moon as well (this can be seen on page 8). The three FITS image cubes each have 600 lines, 600 samples per line, and 20 planes, with a standard FITS header embedded at the beginning of the file and a detached PDS label. Image pixels are 4-byte IEEE floating-point values. The first six planes in the cube are the six segments corresponding to the Band B wavelength (4.3 microns), and planes 7 through 12 are the six segments corresponding to the Band A wavelength (8.3 microns). Planes 13 through 18 give the data acquisition times in msec for each pixel in each of the six segments. These describe when in the scan the data were taken. The values are such that a time datum plus the value for DCESTART (in the FITS header) equals the number of milliseconds from the start of 1996. Planes 19 and 20 give the selenographic longitude and latitude in degrees, respectively, for each pixel. Price et al. (2003) describe the data collection and processing in more detail, although it should be noted that the images in the paper were averaged differently from the images in this data set. The presentation accompanying this data set also contains much of this information. Since the data set is a time series of the eclipse, a mosaic of the Moon is not quantitatively meaningful. For qualitative purposes, though, averaged images of the 4.3 and 8.3 micron data near totality are shown on pages 9 and 10, respectively. Thermal profiles of selected lunar regions during the eclipse are shown and discussed on page 12.
DATA_SET_RELEASE_DATE 2005-06-03T00:00:00.000Z
START_TIME 1996-09-27T02:12:35.746Z
STOP_TIME 1996-09-27T04:25:55.745Z
MISSION_NAME MIDCOURSE SPACE EXPERIMENT
MISSION_START_DATE 1996-04-24T12:00:00.000Z
MISSION_STOP_DATE 1997-02-26T12:00:00.000Z
TARGET_NAME MOON
TARGET_TYPE SATELLITE
INSTRUMENT_HOST_ID MSX
INSTRUMENT_NAME SPATIAL INFRARED IMAGING TELESCOPE
INSTRUMENT_ID SPIRIT3
INSTRUMENT_TYPE N/A
NODE_NAME Geosciences
ARCHIVE_STATUS LOCALLY ARCHIVED
CONFIDENCE_LEVEL_NOTE This data set underwent external peer review from December 19, 2005 to March 15, 2006.
CITATION_DESCRIPTION Kraemer, K., and J. Ward, MSX Lunar Eclipse Observation, MSX-L-SPIRIT3-2/4-V1.0, NASA Planetary Data System, 2005.
ABSTRACT_TEXT The Midcourse Space Experiment (MSX) lunar eclipse observation on September 27, 1996 resulted in six 4.3 micron brightness temperature maps of the moon. In addition, qualitative observations were made at 8.3 microns.
PRODUCER_FULL_NAME KATHLEEN KRAEMER
JENNIFER WARD
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