CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL RECORD_TYPE = STREAM SPACECRAFT_NAME = GALILEO_ORBITER INSTRUMENT_NAME = "NEAR INFRARED MAPPING SPECTROMETER" INSTRUMENT_ID = NIMS OBJECT = TEXT NOTE = "Introduction to the Galileo Near-Infrared Mapping Spectrometer (NIMS) Cube CD-ROM." PUBLICATION_DATE = 1996-02-15 END_OBJECT = TEXT END Contributions by: Bob Mehlman, Frank Leader Institute of Geophysics and Planetary Physics University of California Box 951567 Los Angeles, California 90095-1567 Bill Smythe, Lucas Kamp, Peter Kahn, Doug Alexander Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 Eric Eliason, Chris Isbell United States Geological Survey Branch of Astrogeology 2255 North Gemini Drive Flagstaff, Arizona 86001 January 19, 1996 Version 1.0 CONTENTS 1 - INTRODUCTION 2 - GALILEO MISSION 3 - NIMS INSTRUMENT 4 - SPECTRAL IMAGE CUBES 5 - BROWSE PRODUCTS 6 - DISK DIRECTORY STRUCTURE 7 - INDEX FILES 8 - ANCILLARY FILES 9 - SOFTWARE 10 - DATA PROCESSING CONSIDERATIONS 11 - LABEL KEYWORD DESCRIPTIONS 12 - ACKNOWLEDGEMENTS 13 - WHOM TO CONTACT FOR INFORMATION 14 - REFERENCES 1 - INTRODUCTION This CDROM contains Spectral Image Cubes of Near Infrared Mapping Spectrometer (NIMS) observations of Venus as well as browse products in image form. It is the result of systematic processing of Experiment Data Records (EDRs) acquired acquired by the NIMS instrument during Galileo's Venus encounter (February 10-17, 1990). This document and the AAREADME.TXT file in the top level directory of this disk provide relevant information pertaining to this CD-ROM. 2 - GALILEO MISSION Galileo is a mission to Jupiter to perform long-term studies of the Jovian atmosphere and detailed studies of the Galilean satellites. The mission is divided into a launch/cruise phase and an orbital phase. The spacecraft trajectory required a deltaV Venus-Earth-Earth gravity assist (VEEGA). The cruise is divided into Earth-Venus (EV), Venus-Earth (VE), Earth-Earth (EE) and Earth-Jupiter segments -- with the initials used to associate observations with time. These cruise segments are further divided by spacecraft command loads, which are numbered, but not completely contiguously since some planned loads were later combined or eliminated. Important segments include VE6 (Venus encounter), EV9 and 11 (Earth 1 encounter), EE3 (Gaspra encounter), EE9 and 11 (Earth 2 encounter), EJ2 and EJ3 (Ida encounter) and EJ7 (Shoemaker-Levy 9 impact with Jupiter). The spacecraft is a dual-spinner, with the fundamental coordinate system in EME-1950 (Right Ascension, Declination, and Twist) and a hardware coordinate system in cone and clock. The associated spacecraft geometry is available as SPICE kernels generated by the NAIF group at JPL. The fundamental unit of the spacecraft clock is the RIM ((Realtime Imaging count, 60 2/3 seconds). This is subdivided into 91 minor frames (2/3 seconds each) numbered from 0 to 90. Each minor frame is in turn subdivided into 10 RTIs (RealTime Interrupts), numbered 0 to 9. The spacecraft clock time is usually represented in the notation RIM:MF:RTI, where MF denotes the minor frame. Planned spacecraft events are described in the SSDF (Standard Sequence Data File). It is the source of several other files, including the ORPLN (ORbit PLaNning) file, the SEF (Spacecraft Event File) and the ISOE (Integrated Sequence Of Events) file. These are available through the Galileo Science Catalog. 3 - NIMS INSTRUMENT The Near-Infrared Mapping Spectrometer (NIMS) instrument is an imaging spectrometer covering the wavelength region 0.7 to 5.2 micrometers -- a region not studied by the Pioneer and Voyager spacecraft. Its spectral resolution is 0.025 micron beyond 1 micron, and 0.0125 microns below 1 micron, yielding 204 spectral elements in nominal mode. The nominal pixel size is a square 0.5 x 0.5 milliradians. The instrument acquires data in the order: (1) sampling of 17 detectors, (2) stepping of the scan mirror (20 elements in cross-cone), (3) stepping of the grating (nominally 12 steps per cycle). The nominal 204 wavelength cycle requires 4 1/3 seconds. The detectors (2 Silicon, 15 Indium Antinomide) sample approximately uniformly across the spectrum. A detailed description of the instrument may be found in [1]. Earlier descriptions may be found in references [2,3]. An electronic version of a preprint of [1] is available in the [DOCUMENT.NIMSINST] directory of this CD-ROM. The raw instrument data are organized by spacecraft clock. With a knowledge of the start and stop time of a given observation, the data can be organized into a viewable object, normally known as a qube, stacked images with spatial coordinates on the front and spectral coordinates along the "back" axis. The timing of the instrument data acquisition, with 17 detectors at a grating position sampled at (nearly) the same time, results in slightly offset geometry for each grating step. This is normally adjusted by resampling the data. First results of NIMS observations during the Galileo Venus encounter may be found in [4]. 4 - SPECTRAL IMAGE CUBES 4.1 - Data Set Overview The natural form of imaging spectrometer data is the spectral image cube. It is normally in band sequential format, but has a dual nature. It is a series of "images" of the target, each in a different wavelength, in ascending order. It is also a set of spectra, each at a particular line and sample, over the target area. Each spectrum describes a small portion of the target. When transformed into cubes, the data may be analyzed spatially, an image at a time or spectrally, a spectrum at a time, or in more complex spatial-spectral fashion. NIMS Spectral Image Cube (Mosaic) files are derived from NIMS Experiment Data Records (EDRs), which contain raw data from the Galileo Orbiter Near Infrared Mapping Spectrometer [1]. The raw EDR data have been re-arranged into band sequential form, converted to spectral radiance units based on ground and flight calibration of the NIMS instrument, and (in most cases) projected onto the target based on the position of the spacecraft and target and the orientation of the spacecraft's scan platform. Calibration and geometric information used are the best available at the time of publication of these files, but they are subject to continual improvements as data analysis proceeds. Thus better cubes may be generated in the future. 4.2 - Parameters A band in a NIMS cube or tube is generated for each of the 17 detectors at each grating step. The motion of the grating is determined by the commanded instrument mode: Mode Grating Grating Bands steps increment Fixed Map/Spectrometer 1 0 17 Bandedge Map/Spectrometer 2 variable 34 Short Map/Spectrometer 6 4 102 Full Map/Spectrometer 12 2 204 Long Map/Spectrometer 24 1 408 The wavelengths of the bands are determined by the commanded start and offset grating positions, and by wavelength calibrations conducted on the ground and occasionally during flight. They are also weak functions of grating temperature. The pixels in a cube or tube of a targeted observation are in (scaled) units of radiance, derived from the 10-bit raw data numbers by applying band-dependent sensitivities, which are in turn products of ground and flight calibrations, of the commanded gain state and chopper mode and of the focal-plane-assembly (FPA) temperature. The radiance scaling is band-dependent, and is specified by vectors of offset and multiplier values. 4.3 - Processing The NIMS cube files on this CD-ROM were generated by the Multimission Image Processing System (MIPS) at the Jet Propulsion Laboratory (JPL) from raw NIMS data on EDRs, which are available in a separate CD-ROM series (GO_10xx). For each planned observation, raw 10-bit data numbers have been re-arranged into band sequential form, converted to spectral radiance units according to ground and flight calibration of the NIMS instrument, and (in most cases) projected onto the target according to spacecraft and target position and scan platform orientation, using a complex binning procedure. (For some sparse observations, the projection step is not carried out, but an unprojected "tube" is produced. A secondary "browse" product of this procedure is a hardcopy "mask", a digital image of which accompanies the cube or tube. (See section 10 below for further information about data processing.) 4.4 - Data Format The cube and tube files follow PDS structure and labeling conventions [5,6,7]. A PDS/ISIS label begins each file, and describes all the 'objects' within using ASCII keyword=value statements. The first object is an ISIS history object [8] which describes the various steps of the generation process. The second object is a 2-D histogram of the cube. A third object is a "sample spectrum qube": a 'stack' of six spectral plots, each an average over a selected area of the cube or tube. (These also appear on the hardcopy and digital 'masks'.) The fourth and principal object is the actual NIMS spectral image cube (or tube). Spectral image cube structure follows PDS and ISIS "qube" object standards [6,8]. Chapter 7 of the ISIS System Design (ISD) document [8] contains a detailed discussion of cube structure. The 'core' of the qube is a 3-dimensional array of 16-bit signed integers, arranged in band sequential order: sample, line and band. (ISIS also supports 8-bit unsigned integers and 32-bit real values.) The core of NIMS cubes and tubes on this CD contains scaled 16-bit radiance values, the result of applying the NIMS calibration to 10-bit raw data numbers. The scaling parameters (offset and multiplier) for each band are stored in the label, as are the wavelengths and other band-dependent quantities. The core is followed by a set of backplanes, or 'extra' bands, made up of 32-bit VAX floating point pixels. Cube backplanes contain seven geometric parameters, the standard deviation of one of them, the standard deviation of a selected data band, and 0 to 10 'spectral index' bands, each a user-specified function of the data bands. (The latter might be ratios of bands, or band depths.) The geometric backplanes are latitude, longitude, incidence, emission and phase angle, slant distance and 'intercept altitude'. Tubes may have many more backplanes, since some of the geometric variables are sufficiently grating-position-dependent to require separate backplanes. (See NOTEs in the label, or section 11 below, for details.) Note that current cube display programs in the ISIS system can display useful band images from these cubes, but the band-dependent scaling yields misleading spectral displays. This difficulty can be eliminated by converting the entire cube core to 32-bit floating point: removing the band-dependent scaling and generating true radiances (e.g. using the ISIS RADFLOAT program). Spectra from the resulting unscaled cube are readily understandable. 5 - BROWSE PRODUCTS The 'mask' files in the BROWSE tree of this CD-ROM are digital versions of the hardcopy 'masks' generated by MIPS along with the cubes (or tubes). Each mask contains a summary image, half a dozen average spectra of selected areas keyed to the summary image, various histograms and annotation. For cubes, the summary image is an RGB composite of three bands, user specified, each of which may be computed from combinations of several NIMS cube bands. There is also a 2-D histogram of the cube and two 1-D histograms of the summary image, before and after stretching. For tubes, the summary image is a boresight footprint with graphics superimposed showing the target body and mirror scan. There is also a 2-D histogram. Each digital version included on this CD-ROM is a 3-band RGB image with 8-bit pixels, 1250 lines by 1750 samples, preceded by a VICAR label. It may be displayed with the VICAR VIDS program, or with most generic image display software. Each mask file is accompanied by a detached PDS label, so it may also be displayed with the NASAview program (see section 9 below). 6 - DISK DIRECTORY STRUCTURE The files on this CD-ROM are organized by several top-level directories with subdirectories where appropriate. The following table shows the structure and content of these directories. In the table, directory names are followed by a designation, upper-case letters indicate an actual directory or file name, and lower-case letters indicate the general form of directory names or file names. DIRECTORY or FILENAME CONTENTS Top-level or root directory |- AAREADME.TXT Introduction to the NIMS CUBE CD-ROM. | |- AAREADME.VMS Basic introduction for VMS systems. | |- ERRATA.TXT Errata for earlier volumes, liens for the future. | |- VOLDESC.CAT A description of the contents of this CD-ROM volume in a format readable by both humans and computers. CATALOG This directory contains copies of PDS catalog | files relevant to this CD-ROM. | |- CATINFO.TXT Documentation describing the contents of the | CATALOG directory. | |- MISSION.CAT A description of the Galileo Mission to Jupiter. | |- INSTHOST.CAT A description of the Galileo spacecraft and its | major components, including the orbiter and the | probe. | |- INST.CAT A description of the NIMS instrument and its | operating modes. | |- VENUSMDS.CAT A description of the Cube (Mosaic) dataset for | targeted observations of Venus. | |- VENUSTDS.CAT A description of the Tube dataset for targeted | observations of Venus. | |- REF.CAT Collected references for the above catalog files. DOCUMENT This directory contains document files | (extension name "TXT") describing products, | missions, organization, etc.. | |- DOCINFO.TXT Documentation describing the contents of the | DOCUMENT directory. | |- VOLINFO.TXT Contains detailed information about the | contents of this CD-ROM volume (this file). | |- NIMSINST.TXT A brief description, with references, of the | Near Infrared Mapping Spectrometer (NIMS) | instrument. Each cube file has a label pointer | to this file. | |- NIMSGD This directory contain the NIMS Guide to the | | first Earth/Moon (E1) encounter and to the | | Venus data playback. | | | |- GDINFO.TXT Documentation describing the contents of the | | NIMSGD directory. | | | |- NIMSGD.LBL PDS label describing the NIMS Guide format | | | | (PostScript Versions of the NIMS Guide, with longer chapters | | broken into several files with A,B,C... added to the filename, | | e.g. NIMSGD3A.PS) | | | |- NIMSGD0.PS Title Page | | | |- NIMSGD1.PS Chapter 1: Introduction | | | |- NIMSGD2A.PS Chapter 2, part 1: Encounter overview | | | |- NIMSGD2A.PS Chapter 2, part 2: Encounter overview, continued | | | |- NIMSGD3A.PS Chapter 3, part 1: Encounter geometries | | | |- NIMSGD3B.PS Chapter 3: part 2: Encounter geometries, continued | | | |- NIMSGD4.PS Chapter 4: Observation summaries | | | |- NIMSGD5A.PS Chapter 5, part 1: Detailed observation designs | | | |- NIMSGD5B.PS Chapter 5, part 2: Detailed observation designs, cont. | |- NIMSINST This directory contains a preprint of the NIMS | instrument paper. | |- INSTINFO.TXT Documentation describing the contents of the | NIMSINST directory. | |- INSTPUB.ASC ASCII version of the Text and Tables from the | Instrument paper. | |- INSTFGnn.PS PostScript files for Figures, nn = 01-14, from | the Instrument paper. | |- INSTPUB.LBL PDS label describing ASCII and PostScript files | mentioned above. INDEX This directory contains various index table | and index label files. | |- INDXINFO.TXT Documentation describing the contents of the | INDEX directory. | |- INDEX.TAB Cube information index table for current volume. | |- INDEX.LBL PDS label describing INDEX.TAB content. | |- CUMINDEX.TAB Cumulative cube information index table | |- CUMINDEX.LBL PDS label describing CUMINDEX.TAB content. | |- OBSCAT.TAB Observation characteristics index table, cumulative | over the whole mission up to current volume. | |- OBSCAT.LBL PDS label describing OBSCAT.TAB content. CALIB This directory is a placeholder for NIMS | calibration files. | |- CALINFO.TXT Information file pointing to NIMS calibration | files elsewhere. GEOMETRY This directory is a placeholder for Galileo | geometry files. | |- GEOMINFO.TXT Information file pointing to Galileo geometry | files (SPICE files) elsewhere. SOFTWARE This directory is a placeholder for software | for accessing cube, tube and mask files. | |- SOFTINFO.TXT Information file pointing to software obtainable | elsewhere, and promising software on later CDs | in this series. | |- VMS This directory contains software for VMS systems. | |- CDCOPY.COM Command file used to copy data files from the CD on pre-VMS-6.0 systems. (See SOFTINFO.TXT for information) VENUS Directory containing cubes and tubes of Venus | observations. Cube filenames have the extension | '.QUB'. Tube filenames have the extension '.QUT'. BROWSE Top-level directory for browse products (mask | image files). | |- VENUS Directory containing browse products of Venus | observations. Filenames have the extension '.IMG'. 7 - INDEX FILES Index files are located in the INDEX directory of this disk and have file names ending with the characters ".TAB". An index file is a 'table' arranged by rows (records) and columns (fields) and provides important information about the NIMS data. Some index files are formatted to allow automatic data entry programs to access the data for entry into an existing data base system. In these tables, non-numeric fields are enclosed by double-quote characters, all fields are delimited by commas, and the last two bytes in each record are carriage-control and line-feed characters. Other table files are designed for access by ISIS cube generation software, and lack the quotes, separators and terminators. Both kinds have accompanying PDS label files whose file names end with ".LBL". Each .LBL file is a PDS Object Description Language (ODL) description of the contents of the corresponding .TAB file. ODL documentation is available in the PDS Standards Reference [6]. The following are index files found in the INDEX directory on this CD. Index Description ---------- ----------------------------------------------------- INDEX.TAB Provides selected information about each cube, tube and mask files on the volume. The table contains one row for each cube (or tube) file on the volume. Either a cube (projected data) or tube (unprojected data) is included for each successful observation or observation segment of the target. Information about mask files can be inferred from entries for the corresponding cube (or tube). CUMINDEX.TAB Cumulative version of INDEX.TAB for all volumes up to current volume. (Not on first volume.) OBSCAT.TAB Provides time range and status information about each observation for which data was received, cumulatively for all volumes up to current volume. The following tables provide a detailed description of the contents of the index files. This includes the starting and ending byte positions of each field in the index. These byte positions specify the actual fields and do not include the double-quote marks and commas that may separate the fields. Table 1 - INDEX.TAB and CUMINDEX.TAB -------------------------------------------------- Byte Positions Description --------------------------------------------------------------------------- 2 - 8 CUBE_VOLUME_ID : The CD_ROM volume containing the cube (or tube) file for the observation or observation segment. 12 - 21 CUBE_DIRECTORY_NAME: The CD_ROM directory for the cube (or tube) file, e.g. [EARTH] or [MOON]. The mask file will be found in a subdirectory of the same name under the [BROWSE] root directory. The directory specification is in VMS format; i.e. enclosed in square brackets. 25 - 36 CUBE_FILE_NAME : The name of the cube (or tube) file. Either a cube *or* a tube will exist for a particular observation or observation segment. Cube files have the extension '.QUB'. Tube files have the extension '.QUT'. 40 - 46 MASK_VOLUME_ID : The CD_ROM volume containing the mask file which is the browse product for the cube (or tube). (This field is distinct from CUBE_VOLUME_ID so that either cube/tube or mask alone can be updated on subsequent volumes.) 50 - 81 MISSION_PHASE_NAME : The mission phase during which data was acquired. Phase names are assigned by the Galileo project. 85 - 100 TARGET_NAME : The (primary) target of the observation or observation segment. 104 - 128 DATA_SET_ID : A unique alphanumeric identifier for the entire data set, constructed according to PDS conventions. 132 - 156 SPACECRAFT_NAME : The name of the spacecraft which hosts the instrument referenced in the INSTRUMENT_ID object. 160 - 184 INSTRUMENT_ID : An abbreviated name or acronym which identifies the instrument that took the data. 188 - 198 NATIVE_START_TIME : The spacecraft clock count (rrrrrrrr.mm) at which data acquisition for the cube (or tube) began. 202 - 212 NATIVE_STOP_TIME : The spacecraft clock count (rrrrrrrr.mm) at which data acquisition for the cube (or tube) ended. 216 - 235 START_TIME : The Universal Time Coordinated (UTC, in ISO format) at which data acquisition for the cube (or tube) began. 239 - 258 STOP_TIME : The Universal Time Coordinated (UTC, in ISO format) at which data acquisition for the cube (or tube) ended. 262 - 273 OBSERVATION_NAME: The name assigned to the observation during the Galileo planning process. 277 - 296 PRODUCT_ID: A unique name for the cube (or tube) included on this CD-ROM, which distinguishes it from other cubes generated from the same data. The original filename may be formed by appending a '.QUB' or '.VTUB' extension. The (8.3 format) CD-ROM name may be found in the CUBE_FILE_NAME column. 300 - 309 PRODUCT_CREATION_TIME : The Universal Time Coordinated(UTC) at which the NIMS cube (or tube) product was generated. 312 - 317 MINIMUM_LATITUDE : The minimum latitude of data included in the cube (or tube). 319 - 324 MAXIMUM_LATITUDE : The maximum latitude of data included in the cube (or tube). 326 - 331 MINIMUM_LONGITUDE : The minimum longitude of data included in the cube (or tube). 333 - 338 MAXIMUM_LONGITUDE : The maximum longitude of data included in the cube (or tube). 340 - 345 INCIDENCE_ANGLE : The incidence angle at the approximate center of the spatial area covered by the cube (or tube). 347 - 352 EMISSION_ANGLE : The emission angle at the approximate center of the spatial area covered by the cube (or tube). 354 - 359 PHASE_ANGLE : The phase angle at the approximate center of the spatial area covered by the cube (or tube). 361 - 361 GAIN_MODE_ID : There are 4 NIMS gain states, which determine the gains applied individually to the 14 non-thermal detectors. Gain state 2 is designed for observing a bright Jupiter in each detector. Gain state 3 and 4 are each more sensitive by factors of two and four, respectively. Gain state 1 is similar to gain state 2, except channels 10-14 are each reduced in order to obtain measurements of the Radiometric Calibration Target. 364 - 388 INSTRUMENT_MODE_ID : The principal NIMS instrument modes are LONG, FULL, SHORT and FIXED MAP and the corresponding SPECTROMETER modes. A LONG grating cycle of 24 steps results in 17*24 or 408 wavelengths or bands in a cube. A FULL grating cycle of 12 steps results in 204 bands. A SHORT grating cycle of 6 steps results in 102 bands. A FIXED grating results in only 17 bands. In MAP modes, the secondary mirror traverses 20 cross-cone positions. In SPECTROMETER modes, it is stationary, but samples are taken with the same frequency as in MAP modes. 391 - 395 LINE_SAMPLES : The number of data instances along the horizontal axis of each band of the cube (or tube). 397 - 401 LINES : The number of data instances along the vertical axis of each band of the cube (or tube). 403 - 407 BANDS : The number of spectral bands (or wavelengths) in the cube (or tube). Table 2 - OBSCAT.TAB ------------------------------------- Byte Positions Description ------------------------------------------------------------------------- 1 - 12 OAPEL_ID : The Orbital Activity Profile ELement ID identifies a single planned observation. It is popularly known as the OAPEL name. 14 - 14 SEGMENT_ID : The segment ID identifies a part of an observation which has been separated for processing convenience. (Parts of observations in different instrument modes are usually processed separately.) Ordered segments within an observation are usually represented by alphabetic characters in order, beginning with 'A'. 16 - 19 PROFILE_ACTIVITY_ID : The profile activity ID identifies the type of scan platform activity of the observation segment. Only the first 4 characters of each identifier are used in the table: ALSPINSP All Spin Scan Platform Control CMDRS Instrument Command (Remote Sensing) CSMOS Continuous Slew Mosaic INITRS Instrument Initialization (Remote Sensing) PCINIT Photocalibration Initialization PCREST Photocalibration Restore (termination) RADHTR NIMS Radiometric Heater Control SCIREC Science Record SCITLM Science Telemetry SMOS Start/Stop Slew Mosaic TARGET Target (Scan Platform Positioning) SSI Solid State Imaging (SSI) Command UTIL Utility, such as instrument checkout 21 - 31 NATIVE_START_TIME : The spacecraft clock count that indicates the beginning of the observation segment. 33 - 43 NATIVE_STOP_TIME : The spacecraft clock count that indicates the end of the observation segment. 45 - 46 INSTRUMENT_MODE_NUMBER : A number (0-15) which identifies the NIMS instrument mode during the observation segment: 0 Safe (fixed spectrometer) 1 Full map 2 Full spectrometer 3 Long map 4 Long spectrometer 5 Short map 6 Short spectrometer 7 Fixed map 8 Bandedge map 9 Bandedge spectrometer 10 Stop and slide map 11 Stop and slide spectrometer 12-15 Special sequences (programmable) 49 - 49 GAIN_MODE_NUMBER : A number which identifies the gain state (1-4) of the NIMS instrument during the observation segment. These states vary roughly from low gain (1) to high gain (4) and apply to the non-thermal detectors (1-14) only. 52 - 52 CHOPPER_MODE_NUMBER : A number which identifies the chopper mode of the NIMS instrument during the observation segment: 1 Reference mode 2 63-hertz mode 3 Free-run 4 Off 55 - 55 GRATING_OFFSET : The physical offset (0-7) of the NIMS grating during the observation segment. It defines the physical grating position of logical grating position 0. 56 - 91 The contents of the two Parameter Tables (PTABs) in the NIMS instrument. The PTABs control the operation of the instrument. Six items have been extracted from each 4-byte parameter table. 56 - 73 PTAB A 56 - 58 MODE_REPEAT_COUNT : The mode repeat count is the number of times the grating cycle defined in the PTAB is to be repeated before control is transferred to the other PTAB. It is the first byte of the PTAB. 61 MIRROR_OPERATION_FLAG : The mirror operation flag, if set, indicates that the NIMS secondary mirror is operating, i.e. the instrument is in a MAP mode. If the flag is not set, the mirror remains in position 9 (of 0-19), i.e. the instrument is in a SPECTROMETER mode. The flag is the first bit of the second byte of the PTAB. 64 AUTOBIAS_FLAG : The autobias flag, if set, means that thermal channel autobias is off. This is intended for use only when the NIMS instrument is at room temperature. The flag is normally NOT set, implying that the thermal detectors (15-17) have different gains in each half of the DN range. This flag is the second bit of the second byte of the PTAB. 66 - 67 START_GRATING_POSITION : The start grating position is the first logical position of the grating when the PTAB assumes control of the instrument. It is in the 6 least significant bits of the second byte of of the PTAB. 69 - 70 GRATING_POSITION_INCREMENT : The grating position increment controls the step size between grating positions. It is the third byte of the PTAB. 72 - 73 GRATING_POSITIONS : The number of grating positions (separated by the grating position increment) in one repetition of the operation defined in the PTAB, except for fixed map and safe modes, in which it governs only the motions of the secondary mirror. It is the fourth byte of the PTAB. 74 - 91 PTAB B (see PTAB A above for description and relative location of fields) 94 - 94 ELECTRONICS_CALIBRATION_FLAG : An electronic calibration of the NIMS instrument will occur in the first RIM of the observation if the flag is set. 96 - 96 OPTICAL_CALIBRATION_FLAG : An optical calibration of the NIMS instrument will occur in the first RIM of the observation if the flag is set. 98 - 114 START_TIME : The start time of the observation as a Universal Time in ISO format, corresponding to NATIVE_START_TIME. 117 - 117 REALTIME_FLAG : If the flag is set, the observation was transmitted in the realtime data stream. 119 - 119 RECORD_FLAG : If the flag is set, the observation was recorded on the Galileo tape recorder and transmitted later. 121 - 128 PRIMARY_TARGET_NAME : The primary target of the observation. Besides the various planets and satellites, this may be SKY, STAR (for boresight calibration), DARK (for dark calibrations) or CAL (for optical and radiometric calibrations). 8 - ANCILLARY FILES 8.1 - Calibration Files No calibration files are included on this cube CD-ROM. They are required for processing NIMS EDRs into cubes and tubes, and are available with the EDRs or with the ISIS software as follows. Kay Edwards' map of Galileo boom obscurations as a function of scan platform cone and clock angles is used to remove boom interference from NIMS products. It is available on the various NIMS EDR CD volumes, as well as with the ISIS system. Dark values must be subtracted from raw NIMS data numbers before conversion to radiance units. Dark files are average dark current files derived from "heaven dark" or other special observations at different times in the various encounters, or from off-limb data taken during some observations. They are available on the various NIMS EDR CD volumes, or may be generated from EDR data with ISIS software. NIMS instrument sensitivities and other instrument parameters are required for the conversion of raw NIMS data numbers to radiance units. They are available in NIMS Calibration files and are distributed with the ISIS system. Note that improved versions will be released as developed. 8.2 - Geometry Files No geometry files are included on this cube CD-ROM. They are required for geometric processing of NIMS EDR data into cubes and tubes, and are available with the EDRs or with the ISIS software as follows. The SPICE I kernel describes NIMS instrument geometry. It is available on the NIMS EDR CDs and with the ISIS system. SPICE S, P and C kernels describe spacecraft, planet and scan platform geometry, respectively. They are available from the Galileo Science Data Team. A limited number of SPICE files are delivered with the ISIS system. 9 - SOFTWARE No specific cube access software is provided with this version of the NIMS Cube CD-ROMs. The ISIS (Integrated Software for Imaging Spectrometers) system is available for display and analysis of NIMS cubes and tubes [8,9,10]. The VICAR-labeled masks may be displayed by software in the VICAR system. Also, software for generation of cubes and tubes from NIMS EDRs is available in both the ISIS and VICAR systems. See section 13 below for details. Simple multi-platform software for examining the cubes, tubes and masks will be included on later volumes in this series of CD-ROMs. This software is known as NASAview and is under development by PDS. Versions which access image files are expected to be available soon from the PDS home page on the World Wide Web (http://stardust.jpl.nasa.gov). Versions which access cube files, and which display spectra as well as images, will follow. Until a cube-capable version of NASAview is available, most generic image display systems can be used to display individual bands in a cube or tube. One must first calculate the offset (in bytes) to the image to be displayed. Find the ^QUBE statement in the label, and use its value (v) to determine the starting byte of the first band of the cube: (v-1)*512 + 1. That is, skip (v-1)*512 bytes. Then use the CORE_ITEMS = (samples, lines, bands) statement to find the dimensions of the core, and CORE_ITEM_BYTES to get the size of each pixel (usually 2). To display the first band, offset (v-1)*512 bytes and display a samples by lines image of 16-bit pixels. To display an arbitrary band, say band b, change the offset to (v-1)*512 + (b-1)*samples*lines*pixel_size. One other thing, the cubes on this CD were generated on VAX hardware. (CORE_ITEM_TYPE has the value VAX_INTEGER.) On a Sparcstation, or just about anything but a VAX, DEC Alpha or IBM-type PC, the bytes in each pixel will have to be swapped before display. Similarly, backplanes may be displayed by offsetting the entire core and any preceding backplanes and converting the (4-byte) pixels from VAX to IEEE floating point. A utility command file, CDCOPY.COM, is available in the [SOFTWARE.VMS] subdirectory for use on VMS systems to copy data files from CDROM to VMS magnetic disks. This command file is used in conjunction with the VFS ISO 9660 MOUNT field test kit which provides a pre-VMS-6.0 interface with the CDROM ISO volume and directory standard. See the SOFTINFO.TXT file in the SOFTWARE directory for detailed information on CDCOPY. 10 - DATA PROCESSING CONSIDERATIONS Two sets of software exist to generate NIMS spectral image cubes. One is part of the ISIS (Integrated Software for Imaging Spectrometers) system; the other is part of the VICAR (Video Image Communication and Retrieval) system. Both produce similar, but not identical, NIMS cubes. The differences are in the methods of binning data into a projected space, and in the selection of geometry and other items stored in backplanes of the cubes. Both software sets provide the option of radiometrically and photometrically calibrating the individual data values. Both sets produce cubes with PDS/ISIS labels, which can be read, displayed and analyzed by generic ISIS software [8,9,10] NIMS data from the various Galileo encounters are processed into calibrated cubes, systematically by the VICAR software and selectively by the ISIS software. These cubes are collected on CD-ROMs for distribution to the scientific community. ISIS consists primarily of programs which process, display and analyze data in cube format, data for which may come from NIMS or from other imaging spectrometers. But it is also a programming environment, in which the NIMS-specific cube generation software mentioned above was developed. It is also capable of handling data in "table" format, a capability that is also used in the cube generation software. ISIS was initially developed using the VMS operating system on the DEC VAX series of computers. The basic processing capabilities of the ISIS system are now available for SUN and DEC-Alpha Unix environments, and additional applications are currently being ported to it. VICAR is an image processing system with a long history, which has some multispectral capability, including the cube generation software mentioned above. It is currently available in both VMS and Unix versions. For additional information on ISIS and VICAR system availability and related technical support, see "Whom to Contact for Information", section 13 of this document. 11 - LABEL KEYWORD DESCRIPTIONS Keyword Descriptions for attached labels of NIMS cube and tube files, and detached labels of mask files. Comments are either interspersed with the label statements, or placed on the right hand side of individual statements after an exclamation point. The label values are sometimes shown as 'xxx...' if important variables; others are typical numbers. 11.1 - Cube/Tube Labels (attached) CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL This keyword provides a mechanism for files on this CDROM to conform to the SFDU (Standard Formatted Data Unit) convention. The first 20 bytes identify the file as a CCSDS SFDU entity. The next 20 bytes identify the file as a registered product of the JPL SFDU control authority. The components of both SFDU labels are the control authority identifier (characters 1-4), the version identifier (character 5), the class identifier (character 6), a spare field (characters 7-8), a format identifier (characters 9-12), and a length field indicator (characters 13-20). The version identifier indicates a "Version-3" label, which allows files to be delimited by an end-of-file marker, rather than requiring a byte count to be embedded in the label. The keyword conforms to standard PDS keyword syntax and the value associated with this keyword will always be SFDU_LABEL. RECORD_TYPE = FIXED_LENGTH This keyword defines the record structure of the file. The NIMS EDR files are always fixed-length record files. This keyword always contains the value FIXED_LENGTH. RECORD_BYTES = 512 Record length in bytes for fixed length records, always 512 for ISIS cubes. FILE_RECORDS = xxxx Total number of records contained in the file. LABEL_RECORDS = xx Number of records in the label area of the image file. FILE_STATE = CLEAN An ISIS keyword which distinguishes CLEAN (good) files from DIRTY (incomplete) files. All files on this CD should be CLEAN. CHECKSUM = xxxxxxxxxx CHECKSUM_NOTE = "Unsigned 32-bit sum of all bytes after label records" The sum of all the bytes after the label. This can be used to verify the reading of a cube or tube file. ^HISTORY = xx OBJECT = HISTORY END_OBJECT = HISTORY The (^) character prefixing a keyword indicates that the keyword is a pointer to the starting record of a data object in the file. In this case, the keyword is the pointer to the History Object. The number of records found in an object is determined by differencing the value of the pointer keyword from the value of the next pointer or to the end of the file. There are no label statements describing the history object. It contains the ISIS history of processes which led up to the creation of this data file. It can be read by the ISIS LHLIST program, or by simply TYPEing the file, as long as you stop before you get to the next object. ^HISTOGRAM_IMAGE = xxx OBJECT = HISTOGRAM_IMAGE /* Two dim histogram image structure */ LINES = 256 LINE_SAMPLES = xxx SAMPLE_TYPE = UNSIGNED_INTEGER SAMPLE_BITS = 8 SAMPLE_NAME = BAND LINE_NAME = SPECTRAL_RADIANCE NOTE = "Unannotated two-dimensional histogram 'image'" END_OBJECT = HISTOGRAM_IMAGE These statements describe the 2-d histogram object, which is an 'image' of the number of pixels in 256 radiance bins in each band (up to 408). The samples are unsigned byte values, 0-255. The ISIS program HISTPIC can be used to display it as an image. ^SAMPLE_SPECTRUM_QUBE = xxx OBJECT = SAMPLE_SPECTRUM_QUBE /* Sample spectrum non-standard qube structure */ AXES = 3 AXIS_NAME = (SAMPLE,LINE,REGION) ITEMS = (500,340,6) ITEM_BITS = 4 ITEM_TYPE = UNSIGNED_INTEGER REGION_UPPER_LEFT_LATITUDE = (0.000,30.000,60.000,90.000,85.000, 75.000) REGION_UPPER_LEFT_LONGITUDE = (260.000,260.000,270.000,300.000, 0.000,30.000) REGION_SAMPLES = (5,5,5,5,5,5) REGION_LINES = (5,5,5,5,5,5) NOTE = "Each band is a partially annotated 'image' of a spectral plot over a selected region in the NIMS data cube. Plot is of DN or radiance or I/F versus NIMS_band or wavelength. Nibble pixels may assume 3 values: 0-2, representing black, gray & white. Gray is used to display standard deviation over region. Radiance and I/F may coexist in each plot, with I/F below a cutoff wavelength and radiance above. The cutoff is defined by BDRF_RAD_TRANSITION_WAVELENGTH." BDRF_RAD_TRANSITION_WAVELENGTH = 3.71111 END_OBJECT = SAMPLE_SPECTRUM_QUBE These statements describe a strange object which reproduces the six average spectra appearing on the hardcopy 'mask'. It is a 'qube' consisting of a stack of six 'images', each of which is a spectral plot. The various REGION_ keywords describe the origin and size of the areas over which the spectra are averaged. The ISIS program SPECPIC can be used to display it. ^QUBE = xxxx OBJECT = QUBE A pointer to, and the beginning of the description of, the principal object of this file: a Spectral Image Cube. The standard PDS object name for this structure is 'QUBE'. The QL3 program in VMS ISIS, and the CV program in Unix ISIS can be used to display the bands and spectra of the cube interactively. /* Qube structure: Standard ISIS Cube of NIMS Data */ AXES = 3 AXIS_NAME = (SAMPLE,LINE,BAND) A cube has 3 axes. ISIS software for Standard ISIS cubes requires that the axes be named SAMPLE, LINE and BAND. /* Core description */ CORE_ITEMS = (xxx,yyy,zzz) ! samples, lines, bands CORE_ITEM_BYTES = 2 ! or 4 for unscaled radiances CORE_ITEM_TYPE = VAX_INTEGER ! VAX_REAL for unscaled radiances CORE_BASE = 0.0 CORE_MULTIPLIER = 1.0 CORE_SCALING_NOTE = "True_value = base + (multiplier * stored_value). Scaling of radiance is band-dependent. But values of CORE_BASE and CORE_MULTIPLIER are set to 0.0 and 1.0 for ISIS software compatibility. See BAND_BIN_SCALING_NOTE below." CORE_VALID_MINIMUM = 16#FFEFFFFF# CORE_NULL = 16#FFFFFFFF# CORE_LOW_REPR_SATURATION = 16#FFFEFFFF# CORE_LOW_INSTR_SATURATION = 16#FFFDFFFF# CORE_HIGH_INSTR_SATURATION = 16#FFFCFFFF# CORE_HIGH_REPR_SATURATION = 16#FFFBFFFF# CORE_BELOW_THRESHOLD = -32762 CORE_MISSING_SENSITIVITY = -32754 CORE_NAME = SPECTRAL_RADIANCE ! or RAW_DATA_NUMBER CORE_UNIT = 'uWATT*CM**-2*SR**-1*uM**-1' ! or DIMENSIONLESS for raw DNs CORE_UNIT_NOTE = "To convert these radiances to SI units (W/m^2/sr/uM), the data in the cube must be divided by 100." These statements describe the structure of the 'core' of the cube, which contains the individual bands in each of the NIMS wavelengths. The various CORE_xxxxxx statements describe special values which identify invalid pixels and various kinds of saturation. CORE_NAME and CORE_UNIT describe the scientific content of the pixels. SPATIAL_BINNING_TYPE = FOOTPRINT_AVERAGE THRESHOLD_WEIGHT = 0.00000 FOOTPRINT_GRID_SIZE = 10 EXPANDED_RADIUS = xxxx.xx DARK_UPDATE_TYPE = NOUPDAT FILL_BOX_SIZE = 0 FILL_MIN_VALID_PIXELS = 0 PHOTOMETRIC_CORRECTION_TYPE = NONE These statements describe the parameters of the spatial binning procedure used to generate the cube. /* Suffix description */ SUFFIX_BYTES = 4 SUFFIX_ITEMS = (0,0,11) BAND_SUFFIX_NAME = (LATITUDE,LONGITUDE,INCIDENCE_ANGLE, EMISSION_ANGLE,PHASE_ANGLE,SLANT_DISTANCE,INTERCEPT_ALTITUDE, PHASE_ANGLE_STD_DEV,SPECTRAL_RADIANCE_STD_DEV,'B22/B1', 'B26*2/(B24/2+B28)') BAND_SUFFIX_UNIT = (DEGREE,DEGREE,DEGREE,DEGREE,DEGREE,KILOMETER, KILOMETER,DEGREE,'uWATT*CM**-2*SR**-1*uM**-1',UNKNOWN,UNKNOWN) BAND_SUFFIX_ITEM_BYTES = (4,4,4,4,4,4,4,4,4,4,4) BAND_SUFFIX_ITEM_TYPE = (VAX_REAL,VAX_REAL,VAX_REAL,VAX_REAL, VAX_REAL,VAX_REAL,VAX_REAL,VAX_REAL,VAX_REAL,VAX_REAL,VAX_REAL) BAND_SUFFIX_BASE = (0.000000,0.000000,0.000000,0.000000,0.000000, 0.000000,0.000000,0.000000,0.000000,0.000000,0.000000) BAND_SUFFIX_MULTIPLIER = (1.000000,1.000000,1.000000,1.000000, 1.000000,1.000000,1.000000,1.000000,1.000000,1.000000,1.000000) BAND_SUFFIX_VALID_MINIMUM = (16#FFEFFFFF#,16#FFEFFFFF#,16#FFEFFFFF#, 16#FFEFFFFF#,16#FFEFFFFF#,16#FFEFFFFF#,16#FFEFFFFF#,16#FFEFFFFF#, 16#FFEFFFFF#,16#FFEFFFFF#,16#FFEFFFFF#) BAND_SUFFIX_NULL = (16#FFFFFFFF#,16#FFFFFFFF#,16#FFFFFFFF#,16#FFFFFFFF#, 16#FFFFFFFF#,16#FFFFFFFF#,16#FFFFFFFF#,16#FFFFFFFF#,16#FFFFFFFF#, 16#FFFFFFFF#,16#FFFFFFFF#) BAND_SUFFIX_LOW_REPR_SAT = (16#FFFEFFFF#,16#FFFEFFFF#,16#FFFEFFFF#, 16#FFFEFFFF#,16#FFFEFFFF#,16#FFFEFFFF#,16#FFFEFFFF#,16#FFFEFFFF#, 16#FFFEFFFF#,16#FFFEFFFF#,16#FFFEFFFF#) BAND_SUFFIX_LOW_INSTR_SAT = (16#FFFDFFFF#,16#FFFDFFFF#,16#FFFDFFFF#, 16#FFFDFFFF#,16#FFFDFFFF#,16#FFFDFFFF#,16#FFFDFFFF#,16#FFFDFFFF#, 16#FFFDFFFF#,16#FFFDFFFF#,16#FFFDFFFF#) BAND_SUFFIX_HIGH_INSTR_SAT = (16#FFFCFFFF#,16#FFFCFFFF#,16#FFFCFFFF#, 16#FFFCFFFF#,16#FFFCFFFF#,16#FFFCFFFF#,16#FFFCFFFF#,16#FFFCFFFF#, 16#FFFCFFFF#,16#FFFCFFFF#,16#FFFCFFFF#) BAND_SUFFIX_HIGH_REPR_SAT = (16#FFFBFFFF#,16#FFFBFFFF#,16#FFFBFFFF#, 16#FFFBFFFF#,16#FFFBFFFF#,16#FFFBFFFF#,16#FFFBFFFF#,16#FFFBFFFF#, 16#FFFBFFFF#,16#FFFBFFFF#,16#FFFBFFFF#) BAND_SUFFIX_NOTE = " The backplanes contain 7 geometric parameters, the standard deviation of one of them, the standard deviation of a selected data band, and 0 to 10 'spectral index' bands, each a user-specified function of the data bands. (See the BAND_SUFFIX_NAME values.) Longitude ranges from 0 to 360 degrees, with positive direction specified by POSITIVE_LONGITUDE_DIRECTION in the IMAGE_MAP_PROJECTION group. INTERCEPT_ALTITUDE contains values for the DIFFERENCE between the length of the normal from the center of the target body to the line of sight AND the radius of the target body. On-target points have zero values. Points beyond the maximum expanded radius have null values. This plane thus also serves as a set of 'off-limb' flags. It is meaningful only for the ORTHOGRAPHIC and POINT_PERSPECTIVE projections; otherwise all values are zero. The geometric standard deviation backplane contains the standard deviation of the geometry backplane indicated in its NAME, except that the special value 16#FFF9FFFF replaces the standard deviation where the corresponding core pixels have been 'filled'. The data band standard deviation plane is computed for the NIMS data band specified by STD_DEV_SELECTED_BAND_NUMBER. This may be either a raw data number, or spectral radiance, whichever is indicated by CORE_NAME. The spectral index bands were generated by the VICAR F2 program. The corresponding BAND_SUFFIX_NAME is an abbreviated formula for the function used, where Bn should be read 'NIMS data band n'. For example: B4/B8 represents the ratio of bands 4 and 8." [In a tube, the backplanes contain 4 geometric parameters for each grating position (latitude, longitude, line, sample) and 5 'global' geometric parameters which apply to all grating positions, the NATIVE_TIME of the first grating position, plus the aforementioned 'spectral index' bands. The NATIVE_TIME (spacecraft clock count) is in 'chops', 1/63 second intervals measured from the NATIVE_START_TIME recorded in the label.] STD_DEV_SELECTED_BAND_NUMBER = 10 The above statements describe the individual backplanes of the cube in much the same way the previous statements describe the core. SUFFIX_ITEMS shows that there are no line or sample suffixes on the core, only band suffixes, which we call backplanes. The BAND_SUFFIX_NOTE pretty well explains it all. /* Data description: general */ DATA_SET_ID = 'GO-x-NIMS-4-MOSAIC-V1.0' The PDS defined data set identifier for NIMS cubes, tubes & masks at target x. V = Venus, E = Earth, L = Moon, A = Asteroid, J = Jupiter, JS = Jupiter satellites, JR = Jupiter rings. SPACECRAFT_NAME = GALILEO_ORBITER MISSION_PHASE_NAME = EARTH_2_ENCOUNTER INSTRUMENT_NAME = 'NEAR_INFRARED_MAPPING_SPECTROMETER' INSTRUMENT_ID = NIMS ^INSTRUMENT_DESCRIPTION = "NIMSINST.TXT" The file pointed to is in the DOCUMENT directory, and gives a brief description of the NIMS instrument. TARGET_NAME = MOON START_TIME = 1992-12-08T03:29:41Z ! UTC STOP_TIME = 1992-12-08T04:26:18Z NATIVE_START_TIME = 1650275.0 ! Galileo spacecraft clock count NATIVE_STOP_TIME = 1650331.0 OBSERVATION_NAME = 'E2LNHIRES01' ! Name assiged by the Galileo project OBSERVATION_NOTE = "This is the highest spatial resolution observation of the Moon, includes the polar region and covers phase range 73.4 to 58.7 deg." PRODUCT_ID = "E2LNHIRES01_MSY01" This uniquesly identifies the particular cube generated from this data. MSY stands for MIPS Systematic (processing). PRODUCT_CREATION_DATE = 1994-06-15 PRODUCT_NOTE = "MIPL Systematic Processing Product" IMAGE_ID = (E2L480,'...',E2L591) These identify SSI images taken of the same target, at our near the same time as the NIMS data. INCIDENCE_ANGLE = 51.52 EMISSION_ANGLE = 14.74 PHASE_ANGLE = 66.22 SUB_SOLAR_AZIMUTH = 175.87 SUB_SPACECRAFT_AZIMUTH = 3.34 Various average geometric parameters of the observation, near the center of the spatial area covered. START_SUB_SPACECRAFT_LATITUDE = 65.61 START_SUB_SPACECRAFT_LONGITUDE = 296.45 STOP_SUB_SPACECRAFT_LATITUDE = 55.77 STOP_SUB_SPACECRAFT_LONGITUDE = 321.48 Various geometric parameters, at the beginning and at the end of the observation. MINIMUM_TARGET_CENTER_DISTANCE = 110287.00 MAXIMUM_TARGET_CENTER_DISTANCE = 112998.00 MIN_SPACECRAFT_SOLAR_DISTANCE = 1.476422e+08 MAX_SPACECRAFT_SOLAR_DISTANCE = 1.476686e+08 Various geometric parameters, as ranges throughout the observation. SCAN_RATE_TOLERANCE = 0.230769 MEAN_SCAN_RATE = 0.878685 SCAN_RATE_NOTE = "The unit of SCAN_RATE_TOLERANCE is mrad/s; the unit of MEAN_SCAN_RATE is the Nyquist scanning rate, which depends on the instrument mode: it is one-half FOV (0.5 mrad) per grating cycle." The above relate to the operation of Galileo's scan platform. /* Data description: instrument status */ INSTRUMENT_MODE_ID = FULL_MAP ! or LONG_,SHORT_,FIXED_MAP,... See section 4 (SPECTRAL IMAGE CUBES) for details about the various modes. GAIN_MODE_ID = 1 ! 1-4 CHOPPER_MODE_ID = '63_HERTZ' ! or REFERENCE START_GRATING_POSITION = 00 OFFSET_GRATING_POSITION = 04 GRATING_POSITION_INCREMENT = 02 GRATING_POSITIONS = 12 Instrument modes, etc. (see instrument paper for details) MEAN_FOCAL_PLANE_TEMPERATURE = 66.10 MEAN_RAD_SHIELD_TEMPERATURE = 119.70 MEAN_TELESCOPE_TEMPERATURE = 134.60 MEAN_GRATING_TEMPERATURE = 139.90 MEAN_CHOPPER_TEMPERATURE = 138.90 MEAN_ELECTRONICS_TEMPERATURE = 288.50 Instrument temperatures at the beginning of the observation. MEAN_DARK_DATA_NUMBER = (27.00,27.03,27.21,27.11,26.72,25.72, 24.39,25.04,26.00,24.87,27.96,29.02,27.99,28.24,29.05,27.31, 26.78) MEAN_DARK_DATA_NUMBER_NOTE = "DN value of dark sky for each of the 17 NIMS detectors, averaged over the mirror-position-specific values used in the computation of radiance. The original dark values were obtained from either off-limb portions of the observation or special 'heaven dark' observations for an encounter." GROUP = BAND_BIN /* Spectral axis description */ BAND_BIN_CENTER = (0.6951,0.7080,0.7210,0.7340,0.7470,0.7600, ! Wavelength 0.7730,0.7860,0.7990,0.8120,0.8250,0.8380,0.8340,0.8470, ... ) BAND_BIN_UNIT = MICROMETER BAND_BIN_ORIGINAL_BAND = (1,2,3,4,5,6,7,8,9,10,11,12,13,14, 15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33, ... ) BAND_BIN_GRATING_POSITION = (0,1,2,3,4,5,6,7,8,9,10,11,0,1, 2,3,4,5,6,7,8,9,10,11,0,1,2,3,4,5,6,7,8,9,10,11,0,1,2,3, ... ) BAND_BIN_DETECTOR = (1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2, 2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4, ... ) BAND_BIN_BASE = (3.173410e+03,2.721930e+03,2.397220e+03,2.149710e+03, 1.934290e+03,1.914300e+03,1.960240e+03,2.030100e+03,1.926680e+03, ... ) BAND_BIN_MULTIPLIER = (9.715211e-02,8.440400e-02,7.581943e-02, 6.680306e-02,6.041240e-02,5.889016e-02,6.183865e-02,6.198733e-02, ... ) BAND_BIN_SCALING_NOTE = "True_value = base + (multiplier * stored_value). Scaling of radiance is band-dependent. But see also CORE_SCALING NOTE above." BAND_BIN_SOLAR_FLUX = (155030.0000,149411.0000,143996.0000, 138776.0000,133747.0000,129391.0000,125319.0000,121374.0000, ... ) BAND_BIN_SENSITIVITY = (0.1838,0.2188,0.2521,0.2837,0.3145, 0.3211,0.3093,0.3036,0.3191,0.3283,0.3121,0.2788,0.3007, ... ) BAND_BIN_SENSITIVITY_NOTE = "Sensitivity for each band, in units of DN/radiance_unit (see CORE_UNIT). These values are functions of reported focal plane assembly temperature during the observation and of ground and flight calibration data. They may be used to construct 'idealized data numbers' (DNs which would have been measured by an anomaly-free instrument) by the formula:\n DN = dark_value + sensitivity * radiance,\n where 'dark_value' is approximated by the MEAN_DARK_DATA_NUMBER array. Note that actually measured raw DNs are not obtainable in this way, due to corrections for instrument anomalies (see the referenced INSTRUMENT_DESCRIPTION for details) and possible resampling of the data." END_GROUP = BAND_BIN The above group of statements describe the band dimension of the cube in vector form, giving individual values for each band. BAND_BIN_CENTER is the wavelength. BAND_BIN_ORIGINAL_BAND is an ISIS construct, which preserves the original band number after a subcube is selected. BAND_BIN_GRATING_POSITION & _DETECTOR specify the NIMS grating position & detector for each particular wavelength. BAND_BIN_OFFSET & _MULTIPLIER describe the scaling of radiances into 16-bit integers, on a per-band basis. BAND_BIN_SOLAR flux measures the solar flux in each band at the appropriate distance from the sun. BAND_BIN_SENSITIVITY is described by the NOTE above. GROUP = IMAGE_MAP_PROJECTION /* Projection description */ MAP_PROJECTION_TYPE = POINT_PERSPECTIVE MAP_SCALE = 27.561 MAP_RESOLUTION = 1.100 SUB_SPACECRAFT_LATITUDE = 61.24 SUB_SPACECRAFT_LONGITUDE = 310.87 LINE_SUB_SPACECRAFT_OFFSET = 74.58 SAMPLE_SUB_SPACECRAFT_OFFSET = 72.69 TARGET_CENTER_DISTANCE = 111983.0 LINE_OPTICAL_AXIS_OFFSET = 87.75 SAMPLE_OPTICAL_AXIS_OFFSET = 8.17 FOCAL_LENGTH = 800.0 FOCAL_PLANE_SCALE = 5.000 MINIMUM_LATITUDE = -30.79 MAXIMUM_LATITUDE = 87.83 MINIMUM_LONGITUDE = 358.85 MAXIMUM_LONGITUDE = 224.31 COORDINATE_SYSTEM_TYPE = "BODY-FIXED ROTATING" POSITIVE_LONGITUDE_DIRECTION = WEST A_AXIS_RADIUS = 1737.40 B_AXIS_RADIUS = 1737.40 C_AXIS_RADIUS = 1737.40 MAP_PROJECTION_ROTATION = 50.06 SAMPLE_FIRST_PIXEL = 1 SAMPLE_LAST_PIXEL = 113 LINE_FIRST_PIXEL = 1 LINE_LAST_PIXEL = 150 MAP_PROJECTION_NOTE = "(Historical Note.) For all cubes generated by MIPL before 15-Mar-1994, the LINE & SAMPLE_..._OFFSET label items were computed using a non-standard definition: the offset was reckoned relative to line and sample 0, instead of 1; therefore 1 needs to be added to these old values in order to bring them into conformance with PDS standards." END_GROUP = IMAGE_MAP_PROJECTION The final group of statements describe the projection used to create the cube, or, if this is the label of an (unprojected) tube, the projection used to create backplanes of projection co-ordinates. A detailed description of the keywords may be found in the PDS Standards Reference, Appendix A.20 [6]. END_OBJECT = QUBE This marks the end of the QUBE object description. END This marks the end of the keywords for the label area. Bytes in the label area after the END statement are ignored. 11.2 - Mask Labels (detached) CCSD3ZF0000100000001NJPL3IF0PDSX00000001 PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 1750 FILE_RECORDS = xxxx CHECKSUM = xxxxxxxx CHECKSUM_NOTE = "Unsigned 32-bit checksum of all bytes from image start to EOF." ^IMAGE = ("xxxxxxxx.IMG",offset) This statement points to the image file; the offset, in records, points past the VICAR label to the actual image. DATA_SET_ID = 'GO-x-NIMS-4-MOSAIC-V1.0' SPACECRAFT_NAME = GALILEO_ORBITER MISSION_PHASE_NAME = EARTH_2_ENCOUNTER ! or ? TARGET_NAME = EARTH ! or MOON or ? INSTRUMENT_NAME = 'NEAR INFRARED MAPPING SPECTROMETER' INSTRUMENT_ID = NIMS OBSERVATION_NAME = xxx START_TIME = 1994-199T07:02:26Z ! ISO format STOP_TIME = 1994-199T07:13:11Z SPACECRAFT_CLOCK_START_COUNT = 2486477.17 ! Galileo clock SPACECRAFT_CLOCK_STOP_COUNT = 2486487.74 PRODUCT_ID = "xxxxxxxx.IMG" The mask PRODUCT_ID is formed from the cube or tube PRODUCT_ID by adding the extension '.IMG'. PRODUCT_CREATION_TIME = 1994-mm-dd PRODUCT_NOTE [cube] = "This 'image' is a digital version of a hardcopy 'mask' produced with the spectral image cube of an observation, and serves as a 'browse' product for the cube. It consists of an RGB summary image generated from 3 bands (or 3 functions of several bands) selected from the cube, histograms of the summary image before and after stretching, a 2-D histogram of the cube, 6 average spectra selected from (and keyed to) areas in the summary image, and annotation about the summary image, the cube and the observation." PRODUCT_NOTE [tube] = "This 'image' is a digital version of a hardcopy 'mask' produced with the spectral image tube of an observation, and serves as a 'browse' product for the tube. It consists of a footprint plot over an outline of the target, a 2-D histogram of the tube, 6 average spectra selected from (and keyed to) areas in the tube, and annotation about the tube and the observation." OBJECT = IMAGE LINES = 1250 LINE_SAMPLES = 1750 SAMPLE_TYPE = UNSIGNED_INTEGER SAMPLE_BITS = 8 END_OBJECT = IMAGE END The image object description should be self-explanatory. Most of the keywords in the mask label are described in section 11.1. 12 - ACKNOWLEDGEMENTS The National Aeronautics and Space Administration is charged with the responsibility for coordination of a program of systematic exploration of the planets by U.S. spacecraft. To this end, it finances spaceflight missions and data analysis and research programs administered and performed by numerous institutions. These include the Galileo NIMS project, the University of California at Los Angeles and the Planetary Data System which involves the U.S. Geological Survey and Jet Propulsion Laboratory. The NIMS Cube CDs were designed by Bob Mehlman (UCLA/IGPP) and Bill Smythe (JPL) of the NIMS team, with the advice and assistance of Eric Eliason (USGS/Flagstaff and PDS Imaging node). Bob Mehlman wrote most of the documentation for this CD, and wrote the programs which generated the index table, the detached mask labels, and the checksums for the cube/tube labels. In doing so, he adapted documentation and software written for the NIMS EDR CDs by Chris Isbell (USGS/Flagstaff). Frank Leader (UCLA/IGPP) of the NIMS team contributed the NIMS observation catalog, and adapted the NIMS Guides of the various encounters for inclusion on the CD. Peter Kahn (PDS Central node) checked the file labels, format and contents of the CD for adherence to PDS standards. The VICAR software which generated the cubes, tubes and masks was written principally by Lucas Kamp (MIPS/JPL and NIMS team) with contributions by Justin McNeill (MIPS) and Bob Mehlman. Jan Yoshimizu did much of the production work, and Doug Alexander collected the files for the CD and did the pre-mastering at MIPS. For specific personal contacts in regards to this CD-ROM, see "Whom to Contact for Information", section 13 of this document. 13 - WHOM TO CONTACT FOR INFORMATION For information pertaining to the contents of this CD-ROM. --------------------------------------------------------- Bob Mehlman UCLA/IGPP Box 951567 Los Angeles, CA 90095-1567 (310) 825-2434 NSI-DECnet: GRUMPY::RMEHLMAN ISSAC::RMEHLMAN Internet : rmehlman@igpp.ucla.edu Douglas A. Alexander Jet Propulsion Laboratory Mail stop 168-514 4800 Oak Grove Drive Pasadena, CA 91109 (818) 354-4316 NSI-DECnet : MIPL3::DAA320 Internet : daa320@mipl3.jpl.nasa.gov THE ISIS SYSTEM --------------- To obtain the VAX/VMS version of the ISIS system ------------------------------------------------ Elias Barbinis, NIMS Librarian Jet Propulsion Laboratory Mail stop 183-601 4800 Oak Grove Drive Pasadena, CA 91109 (818) 354-3214 NSI-Decnet : HAPPY::ISISMGR Internet : ebarbinis@issac.jpl.nasa.gov To obtain the Unix version of the ISIS system ------------------------------------------------ Kris Becker U.S. Geological Survey 2255 N. Gemini Flagstaff, AZ 86001 (520) 556-7124 NSI-Decnet : ASTROG::KBECKER Internet : kbecker@flagmail.wr.usgs.gov Technical questions on ISIS NIMS cube generation ------------------------------------------------ Bob Mehlman UCLA/IGPP Box 951567 Los Angeles, CA 90095-1567 (310) 825-2434 NSI-DECnet: GRUMPY::RMEHLMAN ISSAC::RMEHLMAN Internet : rmehlman@igpp.ucla.edu Technical questions on generic ISIS capability ---------------------------------------------- James Torson U.S. Geological Survey 2255 N. Gemini Flagstaff, AZ 86001 (520) 556-7258 NSI-Decnet : ASTROG::JTORSON Internet : jtorson@flagmail.wr.usgs.gov THE VICAR SYSTEM ---------------- To obtain the VICAR system if you are associated with Galileo ------------------------------------------------------------- Helen Mortensen Jet Propulsion Laboratory Mail stop 168-514 4800 Oak Grove Drive Pasadena, CA 91109 (818) 354-0002 Internet : Helen_Mortensen@iplmail.jpl.nasa.gov To obtain the VICAR system if you are NOT associated with Galileo --------------------------------------------------------- COSMIC University of Georgia 382 East Broad Street Athens, GA 30603 (706) 542-3265 Technical questions on VICAR NIMS cube generation ------------------------------------------------- Lucas Kamp Jet Propulsion Laboratory Mail stop 168-414 4800 Oak Grove Drive Pasadena, CA 91109 (818) 354-3214 NSI-Decnet : MIPL1::LWK059, BASHFL::LKAMP Internet : lwk059@mipl1.jpl.nasa.gov ADDITIONAL INFORMATION ---------------------- Information about CD-ROM Hardware and Software and for general assistance in CD-ROM use. -------------------------------------------------- Data Distribution Laboratory MS 525-3610 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 (818) 306-6303 Electronic mail address: Internet: DDL@stargate.jpl.nasa.gov JPL's Data Distribution Lab has produced "Catalog of Scientific CD-ROM Publications". This document describes the Planetary CD-ROM collections and the various CD-ROM titles produced by government agencies. It also identifies software which is available for displaying and processing these data sets. The catalog can be ordered from: PDS Operator MS 525-3610 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 (818) 306-6130 Electronic mail address: NSI/DECnet: JPLPDS::PDS_OPERATOR Information about other PDS Data Products can also be obtained from the PDS Operator listed above. 14 - REFERENCES 1. R. W. Carlson, P. R. Weissman, W. E. Smythe, J. C. Mahoney, and the NIMS Science and Engineering Teams, "Near-Infrared Mapping Spectrometer Experiment on Galileo", Space Science Reviews 60, 457-502, 1992. [This volume also contains papers describing the other Galileo instruments.] 2. Irving M. Aptaker, "A near-infrared mapping spectrometer for investigation of Jupiter and its satellites", SPIE 331 ("Instrumentation in Astronomy IV") IV", 182-196, 1982. 3. R. W. Carlson, "Spectral mapping of Jupiter and the Galilean satellites in the near infrared", SPIE 268 ("Imaging Spectroscopy"), 29-34, 1981. 4. R. W. Carlson et al, "Galileo Infrared Imaging Spectroscopy Measurements at Venus", Science, 253, 1541-1548, 27 September 1991. [This issue of Science also contains papers describing Venus data taken by the other Galileo instruments.] 5. Planetary Data System, April (1995), Planetary Data System Data Preparation Workbook, JPL D-7669, Part 1, Version 3.1. Distributed by the Planetary Data System, Jet Propulsion Laboratory. 6. Planetary Data Systems Standards Reference, version 3.2 (1995), JPL D-7669, Part 2. Distributed by the Planetary Data System, Jet Propulsion Laboratory. 7. Planetary Science Data Dictionary Document, (1992), JPL D-7116, Rev C. Distributed by the Planetary Data System, Jet Propulsion Laboratory. 8. ISIS System Design (ISD), VAX/VMS Build 2 Version, Sept. 28, 1994. Distributed by ISIS Librarian (see section 13 above). 9. ISIS User's Manual, Aug. 25, 1995. Distribued by NIMS Librarian. 10. ISIS Programmer's Manual, Aug. 25, 1995. Distributed by NIMS Librarian.