PDS_VERSION_ID     = PDS3
RECORD_TYPE        = STREAM
OBJECT             = TEXT
  PUBLICATION_DATE = 2019-06-01
  NOTE             = "aareadme.txt describes this volume"
END_OBJECT         = TEXT
END


The Venus Climate Orbiter IR2 Calibrated Data Archive
==============================================================================


Introduction
============

   This document provides an overview of the Venus Climate Orbiter (VCO, also
   known as PLANET-C and AKATSUKI) 2-micron Camera (IR2) calibrated data
   archive, including a description of the directory structure. Additional
   documents included in this data set provide more details, especially the
   'dataset.cat' data set description and the various directory-specific
   '/*/*info.txt' files.

   This data set contains image data taken by IR2 onboard the Venus Climate
   Orbiter spacecraft. See the file 'ir2inst.cat' in the '/catalog' directory
   for a description of the IR2 instrument, and the file 'mission.cat' for a
   description of the Venus Climate Orbiter mission and the file 'vcohost.cat'
   for a description of the Venus Climate Orbiter spacecraft.


File Formats
============

   All '*.txt' documents and other meta information files such as
   descriptions, PDS object definitions, and detached PDS labels 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 macOS operating systems.

   The 'index.tab' file is ASCII text table made of fixed-byte records. The
   detailed format specification for this file can be found in the file
   'index.lbl'. The file 'indxinfo.txt' provides additional information.

   Data product files '*.fit' are FITS format files that are mostly conformed
   to FITS Standard Version 4.0.

   The '*.html' files in the '/browse' directory are hypertext markup language
   (HTML 5.2) files and can be read with a web browser.

   All data files in the archive have detached PDS labels. The PDS label
   provides descriptive information about the associated file. The PDS label
   is an object-oriented structure consisting of sets of 'keyword=value'
   declarations. 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 where to find the object. For all detached labels, the location
   contains the name of the file containing the object. For most labels the
   location consists only of the name of the file being referenced, but for
   the label files corresponding to data product files, it also includes a
   byte offset indicating how far into the file to read before the data itself
   begins. (Each data product file has a variable-length header.) along with
   the starting record or byte number, if there is more than one object in the
   file.

   For example:

      ^PRIMARY_HEADER     = ("ir2_20160507_060824_202_l2b_v10.fit", 1)
      ^IR2_LEVEL2B_HEADER = ("ir2_20160507_060824_202_l2b_v10.fit", 2)
      ^IR2_LEVEL2B_IMAGE  = ("ir2_20160507_060824_202_l2b_v10.fit", 10)

   The first indicates that the header of the primary HDU of FITS file is
   located in the file 'ir2_20160507_060824_202_l2b_v10.fit', beginning at the
   1st record of the file (counting from one). The second indicates that the
   header of the HDU of FITS file for Level 2b image can be also found in the
   same file, beginning at the 2nd record of the file (counting from one). The
   third indicates that the image of the HDU of FITS file for Level 2b image
   can be found in the same file, beginning at the 10th record of the file
   (counting from one).


Naming scheme of orbit number string subdirectories
===================================================

   In '/data' and '/browse' directories, there are subdirectories with orbit
   number string as its name. The orbit number string is defined as 'PVVVV'
   format, where 'P' indicates period before the successful orbit insertion
   ('c', the first character of 'cruise') or after the successful orbit
   insertion, i.e., orbiting phase ('r', the first character of 'revolution').
   'VVVV' indicates orbit number that is represented by zero-padded 4 digits.
   For the period before the successful orbit insertion, we assign the orbit
   number '0000', therefore, the orbit number string is 'c0000'. For orbiting
   phase, the orbit number begins from '0001', and it is incremented when the
   spacecraft passes the periapsis. So we'll have the orbit number strings,
   'c0000', 'r0001', 'r0002', and so on. The orbit numbers for the VCO
   spacecraft are defined in '/extras/orbnum/vco_vVV.orb' of the
   'VCO-V-SPICE-6-V1.0' data set, where VV is the version number of the orbit
   number file.


Volume Contents
===============

   Files on this volume are organized into a set of subdirectories below the
   top-level directory. The following table shows the structure and content of
   these directories. In this table, directory names are enclosed in square
   brackets ([]). See the '*info.txt' files in each directory for specific
   information on the files in the directory, including naming schemes.


   [top-level-directory]
   |
   |-- aareadme.txt           This file.
   |
   |-- errata.txt             Comments and errata on this volume.
   |
   |-- voldesc.cat            Description of the contents of this volume.
   |
   |--[browse]                Directory containing JPEG files created from
   |  |                       files in the 'data' directory for browsing.
   |  |
   |  |-- browinfo.txt        Description of files in the 'browse' directory.
   |  |
   |  +--[l2b]                Subdirectory for level 2b (l2b) data.
   |     |
   |     |-- list.html        HTML file including hyperlinks to HTML files in
   |     |                    each orbit number string subdirectory.
   |     |
   |     |-- list.lbl         The corresponding detached PDS label file.
   |     |
   |     +--[PVVVV]           A series of subdirectories organized by orbit
   |        |                 number string.
   |        |
   |        |-- list_*.html   HTML file that enumerates JPEG files in this
   |        |                 directory.
   |        |
   |        |-- *.jpg         A JPEG file created from corresponding image in
   |        |                 the 'data/l2b' directory.
   |        |
   |        +-- *.lbl         The corresponding detached PDS label file.
   |
   |--[calib]                 Directory containing the calibration files.
   |  |
   |  |-- calinfo.txt         Description of files in the 'calib' directory.
   |  |
   |  |-- *.fit               A calibration file used in the processing of
   |  |                       data in the 'data' directory in FITS format.
   |  |
   |  +-- *.lbl               The corresponding detached PDS label file.
   |
   |--[catalog]               Directory containing PDS catalog objects.
   |  |
   |  |-- catinfo.txt         Description of files in the 'catalog' directory.
   |  |
   |  |-- dataset.cat         Description of the data set.
   |  |
   |  |-- ir2inst.cat         Description of the instrument.
   |  |
   |  |-- ir2ref.cat          List of instrument-specific publications
   |  |                       mentioned in 'ir2inst.cat' file.
   |  |
   |  |-- mission.cat         Description of the mission.
   |  |
   |  |-- person.cat          References for personnel who created this
   |  |                       volume.
   |  |
   |  |-- ref.cat             List of mission-wide publications mentioned in
   |  |                       '*.cat' files.
   |  |
   |  |-- target_dust.cat     Description of the target, cosmic dust.
   |  |
   |  |-- target_earth.cat    Description of the target, the Earth.
   |  |
   |  |-- target_sun.cat      Description of the target, the Sun.
   |  |
   |  |-- target_venus.cat    Description of the target, Venus.
   |  |
   |  +-- vcohost.cat         Description of the spacecraft.
   |
   |--[data]                  Directory containing data files and PDS labels
   |  |                       describing the contents of those files.
   |  |
   |  +--[l2b]                Subdirectory for level 2b (l2b) data.
   |     |
   |     +--[PVVVV]           A series of subdirectories organized by orbit
   |        |                 number string.
   |        |
   |        |-- *.fit         A data product file in FITS format.
   |        |
   |        +-- *.lbl         The corresponding detached PDS label file.
   |
   |--[document]              Directory containing volume related documents.
   |  |
   |  |-- docinfo.txt         Description of files in the 'document'
   |  |                       directory.
   |  |
   |  |-- ir2cal.txt          Description of calibration procedure.
   |  |
   |  |-- imagecoord.txt      Description of image coordinate used in this
   |  |                       data set and relationship with indexes of data
   |  |                       stored in FITS files.
   |  |
   |  |-- onlabels.txt        Description of PDS labels for this data set.
   |  |
   |  |-- vco_fits_dic_vVV.*  FITS Header keyword dictionary file for Venus
   |  |                       Climate Orbiter and corresponding detached PDS
   |  |                       label file.
   |  |
   |  |-- vco_obsprg_vVV.*    Description of observation programs (sequence of
   |  |                       image acquisition) and corresponding detached
   |  |                       PDS label file.
   |  |
   |  +--[ft]                 Directory containing filter transmission data
   |     |                    files.
   |     |
   |     |-- ftinfo.txt       Description of files in the 'document/ft'
   |     |                    directory.
   |     |
   |     |-- ft_ir2_*.tab     Filter transmission data files.
   |     |
   |     +-- ft_ir2_*.lbl     PDS label for each filter transmission data
   |                          file.
   |
   +--[index]                 Directory containing index files.
      |
      |-- indxinfo.txt        Description of files in the 'index' directory.
      |
      |-- checksum.tab        Table of MD5 checksums for files in this data
      |                       set.
      |
      |-- checksum.lbl        PDS label for 'checksum.tab' file.
      |
      |-- index.tab           Index table of the data on this volume.
      |
      +-- index.lbl           PDS label for 'index.tab' file.


Whom to Contact for Information
===============================

   Institute of Space and Astronautical Science (ISAS),
   Japan Aerospace Exploration Agency (JAXA)
   3-1-1 Yoshinodai, Chuo-ku, Sagamihara-shi,
   Kanagawa 252-5210, Japan
   WWW Site: http://darts.isas.jaxa.jp/about.html.en
   Electronic mail address: darts-admin@ml.isas.jaxa.jp


Cognizant Persons
=================

   This archive was designed and produced by Shin-ya Murakami,
   Yukio Yamamoto, and Kevin McGouldrick.