PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = " 2008-02-04, T. Moreau (GFI), initial release" RECORD_TYPE = STREAM RELEASE_ID = 0001 REVISION_ID = 0000 SPACECRAFT_NAME = "VENUS EXPRESS" INSTRUMENT_HOST_ID = VEX INSTRUMENT_ID = ASPERA4 MISSION_NAME = "VENUS EXPRESS" DATA_SET_ID = "VEX-V/SW-ASPERA-2-EXT1-NPD-V1.0" OBJECT = TEXT PUBLICATION_DATE = 2008-09-01 NOTE = "AAREADME.TXT describes the data set VEX-V/SW-ASPERA-2-EXT1-NPD-V1.0" END_OBJECT = TEXT END 1. Introduction This dataset contains data from the Neutral Particle Detector (NPD) component of the ASPERA-4 instrument from the Venus Express mission between the dates of start and end of the extended mission phase 1. The NPD instrument provides measurements of the ENA flux, resolving velocity in the energy range 0.1 - 10 keV and mass (H and 0) with a coarse angular resolution. The general scientific objectives of ASPERA-4 are to study the solar wind and atmosphere interaction, and to characterize the plasma and neutral gas environment in the near-Venus space through energetic neutral atom (ENA) imaging and in-situ plasma measurements. The specific science measurements to carry out these goals are: 1. Integral ENA fluxes in the energy range of 0.1 to 60 keV. Neutral Particle Imager (NPI) 2. Mass/energy resolved neutral hydrogen and oxygen atom spectra in the energy range of 0.1 to 10 keV. Neutral Particle Detector (NPD) 3. Ion energy/mass/angle resolved spectra in the energy range of 0.01 to 36 keV/q for the main ion components H+, H2+, He+, O+, and for the group of molecular ions 20 < M/q < ~80; with 4pi steradian coverage. Ion Mass Analyzer (IMA) 4. Electron spectra in energy range of 10 eV to 20 keV, with up to 4pi steradian coverage. However, due to spacecraft blockage, 4pi coverage is never really achieved. Electron Spectrometer (ELS) The ASPERA-4 archived data sets contain data measurements necessary to satisfy the scientific goals and objectives. The DATASET.CAT file found in the CATALOG directory provides the Neutral Particle Detector (NPD) raw (cnts/accum) data set description. This dataset also contains documentation which describe the ASPERA-4 experiment, including the acquisition, processing, and quality of the ASPERA-4 data. Supporting documentation and label files confirm to the Planetary Data System (PDS) Standards, Version 3.6, Jet Propulsion Laboratory (JPL) document JPL D-7669. Look in the DOCUMENT directory for the following: Instrument Description Document VE-ASP-TN-060402.PDF - Provides detailed information about the ASPERA-4 experiment, instrumentation, and data measurements. Provides also ASPERA-4 information concerning pre-flight testing and flight performance. BARABASHP3.PDF - Provides a full scope of the ASPERA-4 science objectives and detailed information about the experiment. Geometry Document VE-ASP-TN-060402.PDF - Provides sensor numbering and frames information for each of the ASPERA-4 sensors. Provides also ASPERA-4 frames and geometry information. Calibration Documents VE-ASP-TN-060402.PDF - Provides calibration information and report for the Neutral Particle Detector (NPD) instrument. For more information and detail concerning the organization and contents of the ASPERA-4 data sets, refer to the ASPERA-4 Experiment to Archive Interface Control Document (EAICD) found in the DOCUMENT directory (VEX_ASP_CESR_EAICD_V1_4). 2. Disk Format This section is not applicable since the data are stored only electronically. 3. File Formats Text files and label files contain a maximum of 80-byte row-length records, with a carriage return character CR (ASCII 13) and a line feed character LF (ASCII 10) in the last bytes. This allows the files to be read by the MacOS, DOS, Unix, and VMS operating systems. For the catalogue files, the length is 72 including CR/LF, which means 70 characters. All data files are described by PDS labels, either embedded at the beginning of the file or detached. If detached, the PDS label file has the same name as the data file it describes, with the extension .LBL; for example, the file INDEX.TAB is accompanied by the detached label file INDEX.LBL in the same directory. Data files are formatted so that they may be read directly into many database management systems on various computers. All fields are separated by blanks, and character fields are enclosed in double quotation marks ("). Character fields and numeric fields are right justified. The "start byte" and "bytes" values listed in the labels do not include the blanks between fields or the quotation marks surrounding character fields. The records are fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. PDS labels are object-oriented. The object to which the label refers (e.g. IMAGE, TABLE, etc.) is denoted by a statement of the form ^object = location in which the carat character (^, also called a pointer in this context) indicates that the object starts at the given location. 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. For example, ^IMAGE_HEADER = ("F02.IMG",1) ^IMAGE = ("F02.IMG",3) indicates that the IMAGE object begins at record 3 of the file F02.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 ^object = ("filename.ext") ^object = ("filename.ext",n) ^object = ("[dirlist]filename.ext",n) ^object = ("filename.ext",n ) ^object = ("[dirlist]filename.ext",n ) where n is the starting record or byte number of the object, counting from the beginning of the file (record 1, byte 1). indicates that the number given is in units of bytes. filename is the upper-case file name, before the decimal point. ext is the upper-case file name, after the decimal point. dirlist is a period-delimited path-list of parent directories, in upper case, that specifies the object file directory. The list begins on directory level below the root directory of the CD-ROM. '[dirlist]' may be omitted when the object being described is located either in the same directory as the detached label or in a sub-directory named 'LABEL', located one level below the CD-ROM root directory. 4. CD-ROM Contents The files on this volumes are organized in one top-level directory with several subdirectories. The following table shows the structure and content of these directories. In the table, directory names are enclosed in square brackets ([]), upper-case letters indicate an actual directory or file name, and lower-case letters indicate the general form of a set of directory or file names. FILE CONTENTS Top-level directory | |-AAREADME.TXT This text file. | |-ERRATA.TXT Optional file summarizing the known errors. | |-VOLDESC.CAT A description of the contents of this | volume in a PDS format readable by both | human and computers. | | |- [CATALOG] A directory containing files that provide | | a top-level understanding of the mission, | | spacecraft, instruments, and data sets. | | | |-CATINFO.TXT A description of the contents of this | | directory. | | | |-DATASET.CAT ASPERA-4 NPD data set information for the PDS | | catalog. | | | |-INST.CAT ASPERA-4 experiment information for the PDS | | catalog. | | | |-INSTHOST.CAT ASPERA-4 experiment host (i.e.,spacecraft) | | information for the PDS catalog. | | | |-MISSION.CAT Venus Express mission information for the PDS | | catalog. | | | |-PERSON.CAT Personnel information for the PDS catalog | | (Team and PDS personnel responsible for | | generating the archive). | | | |-REF.CAT References mentioned in other *.CAT files. | | | |-RELEASE.CAT Catalog file for the different releases | | | |-SOFTWARE.CAT Software information for the PDS catalog. | | (No software provided) | | | |-TARGET.CAT Target information for the PDS catalog. | | |-[DATA] A directory containing VEX/ASPERA-4 EL | | instrument data files with associated labels | | | |-[TIME PERIOD] Sub-divided into time period directories. | | |-[LABEL] A directory containing include files .FMT | | | |-LABINFO.TXT A description of the contents of this | | directory. | | | |-XXXX.FMT All .FMT files referenced by a pointer within | | each PDS label file | | |-[GEOMETRY] A directory that contains basic cruise | | information | | | |-GEOMINFO.TXT A description of the contents of this | | directory. | | | |-ORB_XXXX.LBL The label for the corresponding ORB_XXXX.TAB | | file | | | |-ORB_XXXX.TAB Spacecraft orbit/attitude calculated for | | several time period | | | |-ORB.FMT ORB.FMT file referenced by a pointer within | | each ORB_XXXX.LBL file | |-[DOCUMENT] A directory that contains documentation | | to help the user understand and use the | | archive data. | | | |-DOCINFO.TXT A description of the contents of this | | directory. | | | |-VEX_ASP_CESR_EAICD_V1_4.LBL | | The label for the Experimenter to Archive ICD. | | | |-VEX_ASP_CESR_EAICD_V1_4.PDF | | The Adobe PDF file of the experimenter to | | Archive ICD | | | |-VE-ASP-TN-060402.LBL The label for the VEX/ASPERA-4 instrument | | manual Issue 1.1 | | | |-VE-ASP-TN-060402.PDF The Adobe PDF file of the VEX/ASPERA-4 | | instrument manual Issue 1.1 | | | |-BARABASHP3.LBL The label for the ESA_SP-1295 paper. | | | |-BARABASHP3.PDF The Adobe PDF file of the VEX/ASPERA-4 | | scientific objectives and instrument | | description. Paper published at ESA Science | | publication, ESA_SP-1295,2007. | | | |-ASPERA4-L1-061016.LBL The label for the L1 VEX/ASPERA-4 data | | description | | | |-ASPERA4-L1-061016.PDF The Adobe PDF file of the L1 VEX/ASPERA-4 data | | description | | | |-ASPERA4_DESC.TXT Description of the ASPERA-4 instruments | | flying onboard the Venus Express spacecraft | | | |-ASPERA4_DESC.LBL PDS label for the instrument description | | file | | | |-VEX_POINTING_MODE_DESC.LBL | | The label for the description of the | | pointing mode conventions | | | |-VEX_POINTING_MODE_DESC.TXT | | Text file describing the pointing mode | | conventions | | | |-VEX_ORIENTATION_DESC.LBL | | The label for the description of the | | spacecraft orientation | | | |-VEX_ORIENTATION_DESC.TXT | | Text file describing the spacecraft | | orientation | | | |-VEX_SCIENCE_CASE_ID_DESC.LBL | | The label for the description of the science | | case of VEX | | | |-VEX_SCIENCE_CASE_ID_DESC.TXT | | Text file describing the science case of VEX | | | |-VEX-SCIOPS-TN-050.LBL | | The label for the VEX mission calendar file | | | |-VEX-SCIOPS-TN-050.PDF | | The Adobe PDF file of the VEX mission | | calendar Issue 1.0 | | | |-VEX_RSSD_LI_009.LBL | | The label for the VEX mission subphases | | index table | | | |-VEX_RSSD_LI_009.TAB | | The index table of the VEX mission subphases | | Issue 2.0. This table is mentioned in EAICD. | | | |-OBSERVATION_TYPE_DESC.LBL | | The label for the description of the | | observation types of VEX | | | |-OBSERVATION_TYPE_DESC.TXT | | Text file describing the observation types | | of VEX | | | |-GRIGORIEV_NPD_REPORT.LBL | | The label for the NPD calibrations reports | | | |-GRIGORIEV_NPD_REPORT.PDF | | The Adobe PDF file of the NPD calibrations | | reports | | |-[INDEX] A directory containing index files which | | describe products published so far or on | | this volume. | | | |-GEO_VENUS.LBL A PDS detached label that describes | | GEO_VENUS.TAB | | | |-GEO_VENUS.TAB The geometrical index file | | | |-INDEX.LBL A PDS detached label that describes | | INDEX.TAB. | | | |-INDEX.TAB A table listing all data products on this | | volume. | | | |-INDXINFO.TXT A description of the contents of this | | directory. | 5. Recommended CD-ROM Drives and Driver Software This section is not applicable since the data are stored only electronically. 6. Errata and Disclaimer A cumulative list of anomalies and errors will be maintained in the file ERRATA.TXT at the root directory of this volume. This file will not be available if no errors are known. Although considerable care has gone into making this volume, errors are both possible and likely. Users of the data are advised to exercise the same caution as they would when dealing with any other unknown data set. Reports of errors or difficulties would be appreciated. Please contact one of the persons listed herein. 7. Whom to Contact for Information VEX Project Scientist: H. Svedhem email: Hakan.Svedhem@esa.int phone: (31) 71 565 3370 fax: (31) 71 565 4697 smail: Postbus 299, 2200 AG Noordwijk, NL VEX Archive Manager: J.J. Zender e-mail: jzender@rssd.esa.int phone: (31) 71 565 4919 fax: (31) 71 565 4697 smail: Postbus 290, 2200 AG Noordwijk, NL VEX Archive Scientist: D. Heather e-mail: dheather@rssd.esa.int phone: (31) 71 565 3388 fax: (31) 71 565 4697 smail: Keplerlaan 1, Postbus 299, 2200 AG Noordwijk, NL VEX Archive Scientist: M. Barthelemy e-mail: Maud.Barthelemy@sciops.esa.int phone: (34) 91 813 1248 fax: (34) 91 813 1139 smail: P.O. Box - Apdo. de correos 50727, 28080 Madrid, Spain For any PSA related issues: PSA Helpdesk: psahelp@rssd.esa.int ASPERA-4 PI: Dr. Stas Barabash Swedish Institute of Space Physics (IRF), Kiruna, Sweden email: stas@irf.se Co-PI: Dr. Jean-Andre Sauvaud Centre d'Etude Spatiale des Rayonnements (CESR), Toulouse, France email: Jean-Andre.Sauvaud@cesr.fr NASA PDS Archivist: Mr. Steve Joy UCLA-IGPP Los Angeles, CA, 90095-1567 email: sjoy@igpp.ucla.edu ASPERA-4 Operation Manager: Mr. Futaana Yoshifumi Swedish Institute of Space Physics (IRF), Kiruna, Sweden email: futaana@irf.se ASPERA-4 Operations and Data Engineer: Mr. Leif Kalla Swedish Institute of Space Physics (IRF), Kiruna, Sweden email: leif@irf.se