THEMIS STANDARD DATA ARCHIVE
1. Overview
This volume contains THEMIS Standard Data Products from observations acquired by the Thermal Emission Imaging System (THEMIS) on Mars Odyssey 2001 (ODY). The imaging system is comprised of a three-mirror anastigmat telescope in a rugged enclosure, a visible/infrared beamsplitter, a silicon focal plane for visible detection, and a microbolometer for infrared detection. A calibration flag provides thermal calibration and a DC restore capability; it will also be used to protect the detectors from unintentional direct illumination from the Sun when the instrument is not in use. Infrared data is collected in 9 wavelengths centered from 6.6 to 15.0 microns at 100 meter per pixel resolution; the 6.6 micron band is collected twice to result in a 10 band image. Visible data is collected in 5 spectral bands at a resolution of 18 meters per pixel.
There are four types of THEMIS Standard Products for each thermal or visible observation collected: raw records (EDR), radiometrically calibrated records (RDR), brightness records (ABR and BTR), and browse images. Only a brief overview of these products is presented in this text; for a complete description of each data product, the user is referred to the DOCUMENT/SDPSIS text on each archive volume. Raw and calibrated thermal and visible records are stored as individual multi-spectral data QUBEs. The header of each raw thermal data QUBE contains a table of instrument diagnostic information sampled throughout the observation. Thermal and visible radiometrically calibrated records are stored as multi-spectral data QUBEs, similar to their raw sources. Thermal brightness temperature records (BTR) and visible apparent brightness records (ABR) are created from one band of the calibrated data and stored in IMAGE files with an attached PDS header. One browse image is provided for each thermal or visible observation, representing the data content available. The browse image is usually derived from the product with the highest processing level achieved for that observation, and is stored as a simple PNG image.
Several
types of THEMIS Special Products may be available for each THEMIS observation: a
geometrically registered image (GEO), and products derived from this projected
image. Geometric projections of thermal
or visible observations are stored as individual multi-spectral,
The THEMIS Standard and Special Data Products are split into independent datasets, and released as separate archive volume sets or as logical volumes within the virtual volume:
|
DATA_SET_ID |
VOLUME_ID |
CONTENTS DESCRIPTION |
|
ODY-M_THM-2-IREDR-v1.0 |
ODTIEv-xxxx |
Raw infrared records and raw infrared calibration records |
|
ODY-M_THM-2-VISEDR-v1.0 |
ODTVEv-xxxx |
Raw visible records |
|
ODY-M_THM-3-IRRDR-v1.0 |
ODTIRv-xxxx |
Calibrated infrared records |
|
ODY-M_THM-3-VISRDR-v1.0 |
ODTVRv-xxxx |
Calibrated visible records |
|
ODY-M_THM-3-IRBTR-v1.0 |
ODTIBv-xxxx |
Infrared brightness temperature records |
|
ODY-M_THM-3-VISABR-v1.0 |
ODTVBv-xxxx |
Visible apparent brightness records |
|
ODY-M_THM-5-IRGEO-v1.0 |
ODTIGv-xxxx |
Infrared geometric projections |
|
ODY-M_THM-5-IRPBT-v1.0 |
ODTIPv_xxxx |
Infrared
projected brightness records |
|
ODY-M_THM-5-VISGEO-v1.0 |
ODTVGv-xxxx |
Visible geometric projections |
where v is the version number and xxxx is the DVD archive volume number. On the virtual volume xxxx is literal, acting as a placeholder for the volume number required for DVD archive volumes.
Data products archived in these volumes are copies of files released by the THEMIS team. Errors and anomalies in the original data and comments about the archive are noted in the ERRATA.TXT file on each volume. Supporting documentation and labels of standard products conform to the Planetary Data System (PDS) Standards, Version 3.4, Jet Propulsion Laboratory (JPL) document JPL D-7669 (6/15/2001) and the Planetary Science Data Dictionary, JPL document JPL D-7116, (7/27/2001).
2. DVD Volume Format
The THEMIS archive DVD volumes have been formatted so that Sun and PC users may access the data. Specifically, the volumes have been formatted according to the ISO-9660 level 1 Interchange Standard. For further information, refer to the ISO-9660 Standard Document: RF# ISO 9660-1988, April 15, 1988.
The DVD volumes do not contain any Extended Attribute Records (XAR). Thus, some VAX/VMS users may have problems accessing files on this volume.
3. File Formats
This
section provides a brief description of the files and data objects available on
the THEMIS archive volumes; complete descriptions are available on each archive
volume in the documents specified below. The THEMIS archive includes text
files in the following formats: ASCII text files, PDF files, HTML files,
PNG and JPG files. The THEMIS archive includes PDS data objects, such as LABELs, QUBEs, and IMAGEs, as well as
All text and detached PDS label files are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of the record. This allows the files to be read by MS-DOS/Windows, Unix, and VMS operating systems.
Documents that contain formatting and figures that cannot be rendered as ASCII text are provided as HTML and PDF files. The hypertext file contains ASCII text plus hypertext markup language (HTML) commands that enable it to be viewed in a Web browser. The PDF (Portable Document Format) file is a proprietary format of Adobe Systems Incorporated a that can be viewed using the free Acrobat Reader software.
PNG "browse" and JPEG "thumbnail" files are provided as a way to quickly view the image contents of a THEMIS observation. Standard image compression algorithms are used to convert the most highly calibrated image available for each thermal or visible observation. PNG files are binary with the data reduced to 8 bits per pixel; the compression algorithm is lossless. JPEG files are binary with the data reduced to 8 bits per pixel; the compression algorithm is lossy.
A PDS label, whether embedded or detached from its associated file, provides descriptive information about the associated file. All PDS labels in the THEMIS Standard Data Archive conform to PDS standards [Planetary Science Data Dictionary, 2001; PDS Standards Reference, 2001]. For examples of the PDS labels used with each type of data product, see the DOCUMENT/SDPSIS text on each archive volume. In general, the PDS label is an object-oriented structure consisting of sets of 'keyword = value' declarations; the object to which the label refers is denoted by a statement of the form:
^object = location
in which the carat character (^, also called a pointer in this context) indicates where to find the object. In an embedded label, the location is an integer representing the starting record number of the object (the first record in the file is record 1). In a detached label, the location denotes the name of the file containing the object, along with the starting record or byte number, if there is more than one object in the file. For example:
^HEADER = ("F01.IMG",1)
^IMAGE = ("F01.IMG",1025 <BYTES>)
indicates that the IMAGE object begins at byte 1025 of the file
F01.IMG, in the same directory as the detached label file. Below is a
list of the possible formats for the ^object definition.
^object = n
^object = n<BYTES>
^object = "filename.ext"
^object = ("filename.ext",n)
^object = ("[dirlist]filename.ext",n)
^object = ("filename.ext",n<BYTES>)
^object = ("[dirlist]filename.ext",n<BYTES>)
where n is the starting record or byte number of the object, counting from the beginning of the file (record 1, byte 1), <BYTES> indicates that the number given is in units of bytes, filename is the up to 8 character, alphanumeric upper-case file name, ext is the 3 character upper-case file extension, and dirlist is a period-delimited path-list of parent directories, in upper case, that specifies the object file directory (used only when the object is not in the same directory as the label file). The list begins at the directory level below the root directory. '[dirlist]' may be omitted when the object being described is located either in the same directory as the detached label or in a subdirectory named LABEL that is located in a higher level of the directory tree (typically root itself).
THEMIS raw and radiometrically calibrated records are stored in PDS
SPECTRAL_QUBE objects as defined in the PDS Standards Reference [2002]. A SPECTRAL_QUBE is a three-dimensional array of binary data values in two spatial dimensions (samples and lines) and one spectral dimension (bands). THEMIS QUBEs may include one or more of the following: an attached PDS label, an ASCII HISTORY data object, a telemetry (TLM) table object, and SUFFIX data planes.
THEMIS geometrically projected images are stored in ISIS CUBE objects which are similar to the PDS SPECTRAL_QUBE objects, but are not intended to conform to the PDS Standards Reference. An ISIS CUBE is a three-dimensional array of binary data values, with an attached label. A PDS compliant detached ASCII label is provided for each THEMIS GEO product. For a complete description of these products and examples of the PDS labels, see the GEOMETRY/GEOMETRY text on the archive volume.
THEMIS thermal brightness temperature records and visible apparent brightness records are stored in PDS IMAGE objects as defined in the PDS Standards Reference [2002]. A THEMIS IMAGE is composed of a PDS header attached to a two-dimensional array of binary data values.
4. Applicable Software
Any software package that can handle multi-spectral data sets can be used to display and analyze the THEMIS Standard Data Products. Hints for opening THEMIS data in commonly available software packages are available as simple text files in the SOFTWARE/DOC directory. The THEMIS team uses the software tool DAVINCI to display and analyze the SPECTRAL_QUBEs and IMAGEs; this software tool is available at http://davinci.asu.edu.
5. Volume Contents
Files on the THEMIS archive volumes are organized into a series of subdirectories below the top-level directory. Some files are only available on the volume for which they are named (ODTxx). A volume specific contents tree is available in Appendix A of the DOCUMENT/ARCHSIS text for each of the six THEMIS archive volumes; the virtual volume is discussed in Appendix B. See the xxxxINFO.TXT files in each directory for specific information on the files in the directory.
The following table shows the generalized structure and contents of the THEMIS archive volumes. In this table, lowercase o's and n's are used as placeholders for orbit and image numbers, while lowercase g's represent the geometry abbreviation.
Top-level directory
| ----- AAREADME.HTM
| ----- AAREADME.LBL
| ----- AAREADME.TXT
| ----- ERRATA.TXT
| ----- VOLDESC.CAT
| ----- BROWSE
| | ----- BROWINFO.TXT
| | ----- IoooXX
| | | ----- Iooooonnn.png
| | | ----- Iooooonnn_small.jpg
| | ----- VoooXX
| | | ----- Vooooonnn.png
| | | ----- Vooooonnn_small.jpg
| ----- CALIB
| | ----- BIAS_FILES
| | | ----- ZEROFRAME*_BIAS.FITS
| | ----- CALIBINFO.TXT
| | ----- CALIB.LBL
| | ----- CALIB.PDF
| | ----- CALIB_APXB.PDF
| | ----- CALIB_FIGS.PDF
| | ----- DESMEAR_FILES
| | | ----- DEZERO*_COEFFS.TXT
| | | ----- ZEROFRAME*_ZERO.FITS
| | ----- IRF_FILE
| | ----- PROCESS_HTM
| | | ----- PROCESS_IR.HTM
| | | ----- PROCESS_VIS.HTM
| | | ----- VISIMAGE00x.GIF
| | | ----- VISIMAGE00x.JPG
| | ----- PROCESS.LBL
| | ----- PROCESS_IR.PDF
| | ----- PROCESS_VIS.PDF
| | ----- SENSITIVITY_FILES
| | | ----- FLAT_FRAMES*.PROF*.FITS
| | ----- STRAYLIGHT_FILES
| | | ----- DESTRAY*_FRAME*_*.FITS
| | ----- TEMP2RAD_FILE
| ----- CATALOG
| | ----- CATINFO.TXT
| | ----- INST.CAT
| | ----- INSTHOST.CAT
| | ----- MARTGT.CAT
| | ----- MISSION.CAT
| | ----- ODTIBDS.CAT
| | ----- ODTIBREL.CAT
| | ----- ODTIEDS.CAT
| | ----- ODTIEREL.CAT
| | ----- ODTIGDS.CAT
| | ----- ODTIGREL.CAT
| | ----- ODTIPDS.CAT
| | ----- ODTIPREL.CAT
| | ----- ODTIRDS.CAT
| | ----- ODTIRREL.CAT
| | ----- ODTVBDS.CAT
| | ----- ODTVBREL.CAT
| | ----- ODTVEDS.CAT
| | ----- ODTVEREL.CAT
| | ----- ODTVRDS.CAT
| | ----- ODTVRREL.CAT
| | ----- PERSON.CAT
| | ----- REF.CAT
| ----- DATA
| | ----- DATAINFO.TXT
| | ----- ODTIBv_xxxx
| | | ----- ODTIBVOL.CAT
| | | ----- IoooXXBTR
| | | | ----- IooooonnnBTR.IMG
| | ----- ODTIEv_xxxx
| | | ----- ODTIEVOL.CAT
| | | ----- IoooXXEDR
| | | | ----- IooooonnnEDR.QUB
| | | | ----- TLM.FMT
| | | ----- RoooXXEDR
| | | | ----- RooooonnnEDR.QUB
| | | | ----- TLM.FMT
| | | ----- SoooXXEDR
| | | | ----- SooooonnnEDR.QUB
| | | | ----- TLM.FMT
| | ----- ODTIRv_xxxx
| | | ----- ODTIRVOL.CAT
| | | ----- IoooXXRDR
| | | | ----- IooooonnnRDR.QUB
| | | ----- RoooXXRDR
| | | | ----- RooooonnnRDR.QUB
| | ----- ODTVBv_xxxx
| | | ----- ODTVBVOL.CAT
| | | ----- VoooXXABR
| | | | ----- VooooonnnABR.IMG
| | ----- ODTVEv_xxxx
| | | ----- ODTVEVOL.CAT
| | | ----- VoooXXEDR
| | | | ----- VooooonnnEDR.QUB
| | ----- ODTVRv_xxxx
| | | ----- ODTVRVOL.CAT
| | | ----- VoooXXRDR
| | | | ----- VooooonnnRDR.QUB
| ----- DOCUMENT
| | ----- ARCHSIS.HTM
| | ----- ARCHSIS.LBL
| | ----- ARCHSIS.PDF
| | ----- DOCINFO.TXT
| | ----- ODY_ORIENT_POINT.TXT
| | ----- SDPSIS_HTM
| | | ----- SDPSIS.HTM
| | | ----- SDPSIS_IMG00x.GIF
| | ----- SDPSIS.LBL
| | ----- SDPSIS.PDF
| ----- GEOMETRY
| | ----- BROWSE
| | |
----- BWS2INFO.TXT
| | | ----- IoooXXBWS2
| | | | ----- Iooooonnn.png
| | ----- BROWSE_DCS
| | | ----- DCSINFO.TXT
| | | ----- IoooXXDCS
| | | | ----- IooooonnnDCS.png
| | ----- GEOINFO.TXT
| | ----- GEOMETRY_HTM
|
| | ----- GEOM_IMG00x.GIF
| | | ----- GEOMETRY.HTM
| | ----- GEOMETRY.LBL
| | ----- GEOMETRY.PDF
| | ----- ODTIGv_xxxx
| | | ----- ODTIGVOL.CAT
| | | ----- IoooXXGEO
| | | | ----- Iooooonnnggg.LBL
| |
| | ----- Iooooonnnggg.CUB.gz
| | ----- ODTIPv_xxxx
| | | ----- ODTIPVOL.CAT
| | | ----- IoooXXPBT
| | | | ----- IooooonnnPBT.IMG
| | ----- ODTVGv_xxxx
| | | ----- ODTVGVOL.CAT
| | | ----- VoooXXGEO
| | | | ----- Vooooonnnggg.LBL
| | | | ----- Vooooonnnggg.CUB
| ----- INDEX
| | ----- CMIDX_IRDCS.LBL
| | ----- CMIDX_IRDCS.TAB
| | ----- CMIDX_ODTIB.LBL
| | ----- CMIDX_ODTIB.TAB
| | ----- CMIDX_ODTIE.LBL
| | ----- CMIDX_ODTIE.TAB
| | ----- CMIDX_ODTIG.LBL
| | ----- CMIDX_ODTIG.TAB
| | ----- CMIDX_ODTIP.LBL
| | ----- CMIDX_ODTIP.TAB
| | ----- CMIDX_ODTIR.LBL
| | ----- CMIDX_ODTIR.TAB
| | ----- CMIDX_ODTVB.LBL
| | ----- CMIDX_ODTVB.TAB
| | ----- CMIDX_ODTVE.LBL
| | ----- CMIDX_ODTVE.TAB
| | ----- CMIDX_ODTVG.LBL
| | ----- CMIDX_ODTVG.TAB
| | ----- CMIDX_ODTVR.LBL
| | ----- CMIDX_ODTVR.TAB
| | ----- INDEX_IRDCS.LBL
| | ----- INDEX_IRDCS.TAB
| | ----- INDEX_ODTIB.LBL
| | ----- INDEX_ODTIB.TAB
| | ----- INDEX_ODTIE.LBL
| | ----- INDEX_ODTIE.TAB
| | ----- INDEX_ODTIG.LBL
| | ----- INDEX_ODTIG.TAB
| | ----- INDEX_ODTIP.LBL
| | ----- INDEX_ODTIP.TAB
| | ----- INDEX_ODTIR.LBL
| | ----- INDEX_ODTIR.TAB
| | ----- INDEX_ODTVB.LBL
| | ----- INDEX_ODTVB.TAB
| | ----- INDEX_ODTVE.LBL
| | ----- INDEX_ODTVE.TAB
| | ----- INDEX_ODTVG.LBL
| | ----- INDEX_ODTVG.TAB
| | ----- INDEX_ODTVR.LBL
| | ----- INDEX_ODTVR.TAB
| | ----- THMIDX_IR.LBL
| | ----- THMIDX_IR.TAB
| | ----- THMIDX_VIS.LBL
| | ----- THMIDX_VIS.TAB
| | ----- INDXINFO.TXT
| ----- SOFTWARE
| | ----- DOC
| | | ----- NASAVIEW.TXT
| | ----- SOFTINFO.TXT
| | ----- SRC
| | | ----- MD5_QUBE.PL
| | | ----- SRCINFO.TXT
6. Whom to Contact for Information
For questions concerning this data set:
PDS -
Electronic mail address: pdsmgr@usgs.gov
7. Cognizant Persons
THM-EDR
and THM-RDR data were provided by Philip R. Christensen, THEMIS Principal
Investigator, with assistance from
Eric Eliason, Patricia Garcia, and Ray Arvidson at Planetary Data System Nodes assisted in the design of the archive volumes.