/*============================================================================*/ /* Streamlined Data Set Template (combined EB and SC data sets) */ /*============================================================================*/ /* Template: Data Set Template Rev: 1993-09-24 */ /* Note: Complete one for each data set. Identify multiple targets */ /* associated with the data set by repeating the 3 lines for the */ /* DATA_SET_TARGET object. Identify multiple hosts associated */ /* with the data set by repeating the 4 lines for the */ /* DATA_SET_HOST object. Identify multiple references associated */ /* with the data set by repeating the 3 lines of the */ /* DATA_SET_REFERENCE_INFORMATION object. */ /* Hierarchy: DATA_SET */ /* DATA_SET_INFORMATION */ /* DATA_SET_TARGET */ /* DATA_SET_HOST */ /* DATA_SET_REFERENCE_INFORMATION */ OBJECT = DATA_SET DATA_SET_ID = "GO-E-NIMS-2-EDR-V1.0" OBJECT = DATA_SET_INFORMATION DATA_SET_NAME = "NIMS Experiment Data Records: Earth/Moon 1 and 2 Encounters" DATA_SET_COLLECTION_MEMBER_FLG = "Y" START_TIME = 1990-330T16:57:54 STOP_TIME = 1992-346T18:44:07 DATA_SET_RELEASE_DATE = 1994-10-03 DATA_OBJECT_TYPE = EDR PRODUCER_FULL_NAME = "Dr. Robert W. Carlson" DETAILED_CATALOG_FLAG = "N" DATA_SET_DESC = " Data Set Overview NIMS Experiment Data Record (EDR) files contain raw data from the Galileo Orbiter Near-Infrared Mapping Spectrometer (CARLSONETAL1992). This raw data requires considerable processing before it is readily amenable to science analysis. The EDRs comprise the base dataset from which spectral image cubes will be created by continually evolving software using successively more accurate calibration and geometry data. Parameters The files consist principally of 10-bit sensor values from the 17 NIMS detectors ordered by time of acquisition, but these are interleaved with NIMS background and housekeeping values, and, less frequently, various instrument temperatures, AACS (scan platform and rotor pointing) data and engineering measurements. Sensor values are measured simultaneously in all detectors; a set of 17 values is acquired at each of 20 cross-track positions (via a secondary scanning mirror) in a period of 1/3 second. A grating may step between mirror scans; as many as 24 steps may result in 20 spectra of as many as 408 wavelengths each. A second spatial dimension is added by spacecraft and scan platform motion. Processing The EDRs are generated by the Multimission Image Processing System (MIPS) at the Jet Propulsion Laboratory (JPL) from data sources derived ultimately from decommutated Galileo telemetry. They are divided into files containing up to 100 RIMs (60 2/3 second intervals) of data. Each file contains the best data available from the several ground stations receiving Galileo telemetry. Data The data are organized into 1024-byte records, one for each minor frame (2/3 second) of spacecraft clock time. In that time, the NIMS instrument has collected sensor values for all 17 detectors over two scans (20 positions down and 20 positions up) of the secondary mirror. A detailed description of the structure of the EDR may be found in the Galileo Software Interface Specification (ZAMANI1991). The same information is available in both human and machine-readable form in the Planetary Data System (PDS) structure files on the NIMS EDR CD-ROM volumes. As received from MIPS, each file has a Vicar label preceding a PDS/ISIS label. The Vicar labels have been removed from the EDRs on the CD-ROMs but they are present in detached form. The PDS/ISIS-labelled EDRs themselves may be readily displayed and further processed by software in the ISIS system, and by PDS utilities. NOTE: The failure of the Galileo high gain antenna will result in extensive modifications to NIMS operations and data structures during Jupiter operations. Extensive editing and compression of NIMS data will occur on the spacecraft, and the EDR structure will necessarily be different during phase 2. Ancillary Data A Postscript-format Guide to the planned observations, including footprint plots on the target, instrument parameters, etc. is included with the EDRs on the CD-ROM, as are tables of parameters for each EDR file, each observation and each RIM of data, files of observed dark values in different modes and gain states, a digitized map of the Galileo booms in cone-clock space and tables of NIMS internal geometry and timing. Calibration files, spike files and SPICE files (spacecraft positions, planetary positions and constants, processed pointing geometry, spacecraft clock versus universal time, etc.) may be included in later volumes of the CD-ROM set. Presently, calibration files are packaged with cube generation software in the ISIS and Vicar systems, and SPICE files may be obtained from the Galileo Science Data Team. Software Simple software is available on the EDR CD-ROMs for displaying the raw data in various ways, but use of this software requires considerable familiarity with the operation of the NIMS instrument. Most science analysis requires generation of spectral image cubes using ancillary geometric data, and decalibration of the raw data numbers. This may be done with one of several similar sets of cube generation programs available in the ISIS and Vicar systems. (Data cubes generated in this way will be made available in a separate series of CD-ROMs.) Programs for displaying validity and status information and for re-attaching the Vicar label to the EDR are also available. Media/Format The NIMS EDRs are archived on CD-ROM for delivery to the Planetary Data System (PDS). Formats are based on standards for such products established by PDS." CONFIDENCE_LEVEL_NOTE = " Confidence Level Overview NIMS EDRs contain essentially raw data as received from Galileo telemetry. These are generally processed into spectral image cubes for science analysis. A fuller discussion of confidence levels will be more appropriate for the spectral image cube dataset. Review The NIMS EDRs are reviewed prior to archiving by the NIMS team. Data received is compared with data expected, and replays of missing data requested. The status and validity information on the EDRs themselves is examined, and spikes (bad points) are identified. Spectral image cubes of NIMS target data are generated and reviewed for spatial data coverage and consistency against observational plans. Format and documentation of the CD-ROM archive volumes are reviewed by PDS. Data Coverage and Quality The EDRs contain flags which indicate the validity of individual subsets of NIMS sensor data. Zeros are used as fill values when data is missing or invalid. Limitations The raw data numbers on the NIMS EDRs are of limited use. Proper science analysis requires the computation of radiances according to the best understanding of the instrument calibration, and proper projection of the data onto the target in the form of spectral image cubes." END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = VENUS END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = GO INSTRUMENT_ID = NIMS END_OBJECT = DATA_SET_HOST OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "CARLSONETAL1992" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "ZAMANI1991" END_OBJECT = DATA_SET_REFERENCE_INFORMATION END_OBJECT = DATA_SET END