PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM SPACECRAFT_NAME = GALILEO_ORBITER INSTRUMENT_NAME = "NEAR INFRARED MAPPING SPECTROMETER" INSTRUMENT_ID = NIMS OBJECT = TEXT NOTE = "Description of calibration files provided with the NIMS Phase 2 EDR CD-ROM set" PUBLICATION_DATE = 2002-07-19 END_OBJECT = TEXT END The CALIB directory contains two types of files: (1) data files required for (non-geometric) processing of NIMS data, such as calibration files and dark files, and (2) engineering values not included in NIMS phase 2 data packets, and therefore left out of NIMS phase 2 EDRs. DARK files (.DRK) are average dark current files derived from "heaven dark" or other special observations at different times during the mission, and from off-limb data taken during ordinary targeted observations. They contain the average dark current values as tables in detector, mirror position and mirror direction, for each of four gain states. CALIBRATION files (.CAL) contain NIMS sensitivities for each detector and grating position in each of four gain states. These sensitivities are based on ground calibration data but are corrected to account for changes in the instrument during flight, as shown by periodic NIMS observations of the Photometric Calibration Target (PCT) and Radiometric Calibration Target (RCT), and by special Optical Calibration (OPCAL) and Electronic Calibration (ECAL) observations. Different calibration files may be needed for different periods of time during the mission. Dark and calibration files are used by ISIS and Vicar cube generation programs to convert raw phase 2 data numbers (DNs) to radiances. They will be included in a special final NIMS CD-ROM volume. Provisional versions of these files may be obtained from the NIMS team. NIMSENGR.TAB is a table of raw engineering DN values returned in phase 2 engineering packets for the period covered by the EDRs on this CD-ROM. The table includes NIMS instrument temperatures, resistances and currents, a hardware status word and some SCLK values and checksums used to track the condition of the NIMS software. The table is described by NIMSENGR.LBL. NIMSTEMP.TAB is a table of a subset of the raw engineering DNs (from NIMSENGR.TAB) converted to engineering units. These are all temperatures and are expressed in degrees Kelvin. This table is described by NIMSTEMP.LBL.