PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2011-06-27 NOTE = "Description of the DOCUMENT directory contents for NEAR MSI archive volumes" END_OBJECT = TEXT END DOCUMENT/ Directory Contents ============================ This directory contains the combined documentation included on the original DVD volumes. The description following is a combination of that provided in the DOCUMENT directories of the volumes. DOCUMENT Directory Contents The DOCUMENT directory contains documentation files for NEAR MSI archive volumes. The files listed below are found in this directory. DOCINFO.TXT - The file you are reading. ACRONYMS.TXT - A file containing acronyms specific to the NEAR mission. INSTRUMENT - Directory containing instrument specific documentation. MISSION.LBL - PDS label for MISSION.PDF. MISSION.PDF - NEAR mission overview document. MISSION.TXT - File referring to NEAR mission overview in /CATALOG/MISSION.CAT. MSICAL.TXT - MSI calibration document OBSERVATION_LOG - Directory containing MSI observation information. YYYY/DOY/*.TXT - Files which describe calibration results YYYY/DOY/*.LBL - PDS labels associated with the .TXT files. The YYYY/DOY files are generated by the calibration process in order to quickly describe the calibration results. They are generated as part of the calibration software. They are a quick reference for understanding which images were processed to the various levels of calibration as described in CALINFO.TXT. These files also assist in describing those images for which there there was no calibration, and provides the logic behind excluding them from the calibration process. These files are located in the DOCUMENT/YYYY/DOY directory corresponding to the DATA/yyyy/doy on volumes 2-n (where necessary). The file MSI_VERIFY.TXT contains information pertaining to the set of images taken during a day's observations. Its format is a columnar list followed by text. The columnar list has 7 columns, one each for: the image filename, the mean value of the pixels in the raw image, the standard deviation of the pixel values in the raw image, the minimum value of the pixels in the raw image, the maximum value of the pixels in the raw image, the number of null pixels (pixel values not received on the ground), and the number of saturated pixels. The following text lists from the image header: the exposure time in ms from the housekeeping data, the number of transfer frames that comprise the image, the image number in the image acquisition sequence, the sequence identification number, and the filter wheel position from filter wheel fiducials. The file MSI_PROBLEMS.TXT contains information pertaining to the set of images taken during a day's observations. It lists the name of the files that have the following problems: 1) filter wheel out of position, 2) filter wheel in position but not locked, 3) deck temperature not recently updated from spacecraft housekeeping, 4) missing transfer frame(s), and 5) saturated pixels. The information is based on the contents of the raw image header. The file CLEAN_*.TXT is a file generated for the radiometric calibration process that subtracts a zero millisecond exposure image from a non-zero millisecond exposure image [MURCHIEETAL2000]. It pertains to those images in the sequence *. The file contains two columns; the first column is the non-zero exposure image filename and the second column is the zero exposure image filename. The file CUTLS_*.TXT lists those images from sequence * that were not calibrated for one of four reasons. 1) For images calibrated to units of I/F, the target body was not contained within the image frame (which occurs when the maximum pixel value is less than 250). 2) The image exposure time was less than 1 millisecond. 3) The image contains 50% or more null pixels. 4) The image has a data quality index (dqi) which indicates the filter wheel is out of position. Each line in the file gives an image filename and the reason for exclusion from calibration. The file NORMK_*.TXT is created during the image deblurring process for those images in the sequence designated by *. The file contains three columns that list the image filename, the fixed value of the normalization coefficient actually used in the image processing [LIETAL2000], and the calculated value of the normalization coefficient per image. Deviations from the fixed value are most likely due to changes in out-of-field light leakage [MURCHIEETAL2000]. The file NZERO_*.TXT lists those images for which a matching zero millisecond exposure image was expected but not found (due to transmission problems). It pertains to those images in the sequence designated by *. The format of the file is a single column of image filenames.