Access to Astronomical Catalogues

B/hst               HST Archived Exposures Catalog         (STScI, 2007)
The Archived Exposures Catalog from the HST (Hubble Space Telescope)
     STScI Team
    <Space Telescope Science Institute (1990-2007)>
ADC_Keywords: Observatory log

Mission_Name: HST


Description:
    This catalogue is a copy of the Archived Exposures Catalog (AEC)
    compiled from the Hubble Space Telescope Data Archive database, with
    an indication about the existence of scientific images or spectra.
    It provides a summary of completed HST science observations.

    This catalogue contains also WFPC2 observations stacked into
    associations which usage is recommended for a large fraction of the
    WFPC2 images (see details in the "WFPC2 Associations" section below).

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
launch.dat       198    40008   First period from launch (1990Apr) to 1993Dec
sm93.dat         198    46137   Period between 1993Dec to 1997Feb
sm97.dat         198   271761   Since 1997Feb, until 2004May (Version 2005-Mar)
sm02.dat         198   151599   Servicing Mission `02 (Version 2007-Dec)
wfpc2.dat        180    15343  *HST WFPC2 associations, Version 1.

Note on wfpc2.dat:
    This table includes all WFPC2 observations released before 1 September
    2002, combined into "associations" to give deeper, cosmic-ray free,
    and astrometrically corrected images; details about this new archive
    are given in the "WFPC2 Associations" section below.


See also:
    http://archive.stsci.edu/hst/index.html : Hubble Data Archive Home Page
    http://archive.stsci.edu/hst/aec.html : Archived Exposures Catalog Page
    http://cadcwww.hia.nrc.ca/wfpc2/ : CADC home page for the WFPC2 Associations
    http://cadcwww.hia.nrc.ca/hst/science_help.html : HST Help Page


WFPC2 Associations:
    The Canadian Astronomical Data Center (CADC), the Space Telescope
    European Coordination Facility (ST-ECF) and the Multimission Archive
    at STScI (MAST) are pleased to make available combined images from the
    Wide Field Planetary Camera 2 of the Hubble Space Telescope. These
    combined images are the products of the basic registration and
    averaging of related sets of WFPC2 images, referred to as
    associations, that is usually performed by archival researchers after
    the retrieval of individual images. As of November 2002, over 15,000
    combined images have been created from associations of nearly 50,000
    individual WFPC2 images. This product of many person-years of
    development at CADC and ST-ECF form a set of high-quality astronomical
    data that should be useful for a wide range of investigations. They
    also provide better previews of a given field than the individual
    WFPC2 images. More details about the WFPC2 are given in the paper
    "Enhanced WFPC2 Associations" by Alberto Micol and Daniel Durand
    in the ST-ECF Newsletter of January 2002, p. 14.

    This initial release (November 8, 2002) of the WFPC2 Associations
    Science Products should be viewed as a "shared-risk" product release
    and users should consult the Data Quality assessement information that
    is available on the WFPC2 Associations page at
    http://cadcwww.hia.nrc.ca/wfpc2/

    A second release is planned for 2004 where more extensive
    documentation will be provided, including a refereed publication
    describing the processing methods and results.

    An acknowledgement of the usage of the WFPC2 Associations would also
    be appreciated in your publication, as being obtained "from the CADC":
      "Guest User, Canadian Astronomy Data Centre, which is operated by
      the Herzberg Institute of Astrophysics, National Research Council
      of Canada."
Byte-by-byte Description of file: launch.dat sm*.dat

Byte-by-byte Description of file: launch.dat sm*.dat

   Bytes Format Units   Label     Explanations

   1- 30  A30   ---     Target    Target Name, as given by the proposer
  32- 33  I2    h       RAh       Right Ascension J2000 (hours)
  35- 36  I2    min     RAm       Right Ascension J2000 (minutes)
  38- 42  F5.2  s       RAs       [0,60] Right Ascension J2000 (seconds)
      44  A1    ---     DE-       Declination J2000 (sign)
  45- 46  I2    deg     DEd       Declination J2000 (degrees)
  48- 49  I2    arcmin  DEm       Declination J2000 (minutes)
  51- 54  F4.1  arcsec  DEs       [0,60] Declination J2000 (seconds)
  56- 61  F6.2  deg     v3       *V3 roll angle during observation
  63- 68  A6    ---     fov      *The field of view configuration
  70- 84  A15   ---     config   *Instrument configuration
  86-100  A15   ---     Mode      Instrument operating mode
 102-113  A12   ---     Aper     *Apertures used
 115-129  A15   ---     Spec     *Spectral elements used.
 131-135  I5    0.1nm   wave     *"Central" wavelength of the observation
     137  A1    ---     flagC    *[TF] Flag indicating corrective optics
 139-143  I5    s       expTime   Length of exposure (in seconds)
 145-149  I5    ---     propID    Proposal ID.
 151-159  A9    ---     Dataset   Dataset name, uniquely identifies the data
                                        for a given exposure.
 161-164  I4    yr     ObsDate.Y *? Observation starting time (year)
 166-167  I2    "month" ObsDate.M  [1,12]? Observation starting time (month)
 169-170  I2    d      ObsDate.D  [1,31]? Observation starting time (day)
 172-173  I2    h      ObsDate.h  [0,24[? Observation starting time (hour)
     174  A1    ---     ---       [:] Separator
 175-176  I2    min    ObsDate.m  [0,60[? Observation starting time (minute)
 179-182  I4    yr     RelDate.Y  Release Date (year)
 184-185  I2    "month" RelDate.M  [1,12] Release Date (month)
 187-188  I2    d      RelDate.D  [1,31] Release Date (day of month)
 190-191  I2    h      RelDate.h  [0,24[ Release Date (hour)
     192  A1    ---     ---       [:] Separator
 193-194  I2    min    RelDate.m  [0,60[ Release Date (minute)
     196  A1    ---     Sp        [S] Existence of Spectrum Preview
     197  A1    ---     Im        [I] Existence of Image Preview
     198  A1    ---     Im1       [1] Existence of a second preview

Note on v3:
     The roll angle is the angle between the telescope axis and the
     line of sight.
Note on fov:
     "LAUNCH" for the first period from launch (1990Apr) to 1993Dec
     "SM93"   for the period between 1993Dec to 1997Feb
     "SM97"   since 1997Feb.
Note on config:
     The basic instruments are:
     FGS   = Fine Guide Sensor (astrometer, interferometer)
     FOC   = Faint Object Camera (imager), see details at
             http://www.stsci.edu/ftp/instrument_news/FOC/topfoc.html
     FOS   = Faint Object Spectrograph, see details at
             http://www.stsci.edu/ftp/instrument_news/FOS/topfos.html
     HRS   = High Resolution Spectrograph
     HSP   = High Speed Photometer
     NIC   = NICMOS (Near Infrared Camera and MultiObject Spectrometer,
                imager, spectrometer)
             http://www.stsci.edu/instruments/nicmos/topnicmos.html
     PC    = Planetary Camera (imager, see WFPC / WFPC2)
     STIS  = Space Telescope Imaging Spectrograph, see
             http://www.stsci.edu/cgi-bin/stis?cat=core
     WFC   = Wide-Field Planetary Camera 1 from April 1990 to November 1993,
             see http://www.stsci.edu/ftp/instrument_news/WFPC/wfpc1_top.html
     WFPC2 = Wide-Field Planetary Camera Version 2 since November 1993, see
             http://www.stsci.edu/instruments/wfpc2/wfpc2_top.html
     ACS   = Advance Camera for Surveys, since March 2002, see
             http://www.stsci.edu/hst/acs/
Note on Aper:
     Multiple apertures are delimited by semicolons
Note on Spec:
     The designation depends on the instrument used.
     The most common values start by:
     E: Echelle spectrographs
     F: Filters, followed by the mean wavelength (in nm or 10nm
        depending on the instrument), and the indication of the
        passband width as W(wide), M(medium), N(narrow)
     G: Gratings
     P: Polarimeters, prisms, pupils
Note on wave:
     The central wavelength, in Angstroms, of the observation. For images,
     this is the central wavelength of the filter used, while for spectra,
     it is midpoint of the wavelength range of the spectrum.
Note on ObsDate.Y:
     A few observations (mostly in the "launch" file) have no associated
     observation date.
Note on flagC:
     Flag indicating corrective optics were used (i.e., COSTAR, WFPC2)
     as True or False.


Byte-by-byte Description of file: wfpc2.dat

   Bytes Format Units   Label     Explanations

   1-  4  I4    ---     propID    Proposal ID og the Association
   6- 14  A9    ---     AssocID   Association ID (filename)
  16- 23  F8.4  deg     RAdeg     Right Ascension (J2000)
  25- 32  F8.4  deg     DEdeg     Declination (J2000)
  34- 42  I9    s       ObsStart  Date of First shutter open action
                                   (in DMF = seconds since 01-Jan-1980)
  44- 52  I9    s       ObsEnd    Date of Last shutter close action
                                    (in DMF = seconds since 01-Jan-1980)
  54- 61  F8.1  s       ExpTime   Total exposure time for this association
  63- 71  I9    s       Creation  Date (DMF time = seconds since 01-Jan-1980)
                                    of the generation of this association
  73- 81  I9    s       RelDate   Release date for the association
                                    (DMF time since 01-Jan-1980)
  83- 89  A7    ---     FGSlock  *Indicate the quality of the guiding
  91- 96  F6.2  deg     v3       *V3 roll angle during observation
  98-127  A30   ---     Target    Target Name, as given by the proposer
 129-143  A15   ---     Filter    Filter (s) used for the Association
 145-148  I4    0.1nm   Bw        ? Filter bandwidth in Angstroems
 150-154  I5    0.1nm   wave      ? "Central" wavelength of the observation
 157-169  A13   ---     ExpQual   Exposure quality
                                   (INDETERMINATE, INTERRUPTED, NORMAL)
 171-174  A4    ---     fov       Configuration of field of view (SM-1 or SM-2)
 176-178  I3    ---     Nmem      Number of members for this association
     180  I1    ---     Atyp     *Association type

Note on FGSlock: the values are
    FINE (use of guide stars),
    GYROS (use of the gyroscopes)
    FINE/GY (mixed mode), or
    UNKNOWN
Note on v3:
    The roll angle is the angle between the telescope axis and the
    line of sight.
Note on Atyp:
    The association number has the following meaning:
  blank or
     0: a single exposure, not a real association
     1: the members' offsets from the leader of the association
        (defined to be the first deepest exposure) were all derived
        from WCS information.
     2: The members' offsets from the leader of the association were
        all derived from jitter information.
     3: The members' offsets from the leader of the association were
        partly derived from WCS and partly from jitter information.
     4: The members' offsets from the leader of the association were
        all measured by cross-correlation.
     5: The members' offsets from the leader of the association were
        partly derived from cross-correlation and partly from WCS
        information.
     6: The members' offsets from the leader of the association were partly
        derived from cross-correlation and partly from jitter information.
     7: The members' offsets from the leader of the association were partly
        derived from WCS, partly from jitter, and partly from
        cross-correlation information.


History:
    The file is monthly updated from HST files.
    The WFPC2 Associations (wfpc2.dat) was kindly supplied by CADC
        in October 2003.

Acknowledgements:
  It is a pleasure to thank Robert Hanisch 
  for the access and installation of the data files,
  and Daniel Durand  for the details about
  the previews and the WFPC2 Associations.
(End)                                     Francois Ochsenbein [CDS]  06-Sep-2007