metadata tree with annotated exemple

Francois Bonnarel bonnarel at alinda.u-strasbg.fr
Thu Apr 17 16:34:34 PDT 2003


                  Metadata tree Some documentation for a metadata-tree 
                         ====================================== 
                  Mark Allen and François Bonnarel Version 0.1

Introduction
============
Browsing and visualization of image datasets will be an
important part of Virtual Observatory operations. Such
datasets may range from a small set of images stored on
a local disk, to the terabyte collections of modern
surveys made accessible via various Web Services. Standardized
and scalable descriptions of image metadata will be required to
enable dataset browsing, selection and visualization.

The Metadata Tree that was developed for the AVO 1st year
demonstration represents a prototype implementation of a
scalable, hierarchical metadata description (in VOTABLE/XML)
of an image dataset. This component of the AVO prototype was built as
a customization of the Load feature of the Aladin sky atlas,
and was designed specifically for the GOODS dataset. Using a
VOTABLE description, it displays a tree view of the data available
within a specified region (or range of parameters), allows display
of fields-of-view outlines, and provides feedback between the tree
and visualization window. The metadata description includes the
location and retrieval parameters for the data, in the case of
GOODS this was basically a http-get template for the GOODS data server
at the CDS.

Following user feedback on the Metadata Tree component of the
AVO prototype it was decided to implement a generalized Metadata
Tree function in the public version of the Aladin sky atlas
(version 1.5 ?). This allows description of other datasets (local or
remote) in the same way as was done for the GOODS dataset, so
that they have similar functionality within Aladin.

This document outlines how to define a VOTABLE description
of a dataset for use with Aladin.


Relationship to the IDHA Data Model
===================================
The metadata description of the GOODS data used for the AVO
demo was based on a generic description of astronomical data
being developed by the IDHA data model project. The goal of the
IDHA data model project is to describe the information content
of image archives and datasets. In the IDHA data model the
metadata are coded as objects, with logical links between them.
The graph of the IDHA data model is shown at 
http://alinda.u-strasbg.fr/IDHA/lastmodel.

While the use of the data model is not required to generate
the VOTABLE for a general dataset, it is instructive to see how
the general form of the VOTABLE description relates to the data
model graph. Various tree structures may be extracted from the model
graph. In general this is done by starting at a node, and following
various links, avoiding reverse and circular links. In the case of
GOODS, the tree was chosen with a hierarchy organized in terms of:

ObservingProgram - ObservingGroups - ProcessedObservations

This can be described as one "view of the data model",
but it is also possible to use the model to define trees with
different hierarchies, and different starting points. For example
by starting from ProcessedObservation one may generate a tree
that has branches describing the instrument used, and the observing 
conditions etc.


VOTABLE description of a dataset
================================

Here we describe in detail how to structure a VOTABLE description
of a dataset for use with the Aladin Metadata Tree. VOTABLE has the
capability of describing not only flat table structures, but can also
describe a hierarchical tree. The Metadata Tree is expressed in VOTABLE by
recursive use of the <RESOURCE> element. Each <RESOURCE>
element represents a node of the tree. The children of the nodes appear
as new <RESOURCE> elements included in the previous one.

NODES
-----------
In this description we make use of three different kinds of nodes:
"ObservingProgram", "Observation_Group", and "ProcessedObservation".
These relate to parts of the data model with the same name.

"ObservingProgram" nodes are intended to be the root nodes. Several root
nodes may occur in a single document.

"Observation_Group" nodes are the children of "ObservingProgram" nodes,
or other "Observation_Group" nodes. These nodes are intended to be the
main way of subsetting the dataset into a hierarchy.

"ProcessedObservation" nodes are children of the "Observation_Group"
nodes and are intended to contain the description of a subset of the
image metadata that will be useful to display, for example field
centre coordinates and sizes. This is intended for information relevant
to an Astronomer.

"StorageMapping" nodes are linked to the "ProcessedObservation". They are
intended to contain detailed metadata about the images that are required
for using the images in an interface.


NODE ATTRIBUTES
-------------------------------

The attributes of a node are defined within the <TABLE> part of the
<RESOURCE> element.  Each attribute of the model class is
coded as a <FIELD> in the <RESOURCE>.
The use of these attributes is necessary to enable the full functionality
of the Metadata Tree within Aladin. The tree will however minimally
function provided the main node definitions are included.
We now provide a list of the attributes we are using, and define them
as recommended or optional.
A tree with all the recommended attributes will be called an IDHA metadata tree 
(Image Data Hierarchical Access tree)
  
For ObservingProgram, the <FIELDS> or attributes are:

* Name (recommended),     the ObservingProgram name.
* Organisation(optional), the name of Organisation(s) performing Observing Program
* Begin(optional),        the Begin date of the survey
* End(optional),          the End date of Observing program
* SpectralDomain(recommended), the General spectral domain (Optical X-ray ...)

For Observation_Group, the <FIELDS> or attributes we have are:

* Selection_Criterion(recommended), for the Sampled parameter.
  A sampled parameter can be any attribute of any class of the data model
  considered useful. For example: Filter name (or filter range), 
  epoch of observation, Polarizer state, etc ...
* Selection-Range(recommended) , the Constraint on the sampled parameter
(Inside the Observation_Group resource we can find any resource describing
one aspect of the ObservingConfiguration on which the selection has been
made: in our annotated exemple, it is the case for the filter resource)

For Processed Observation, the <FIELDS> or attributes we have are:

* Observation_Name(recommended) , the name of the Observation
* ReferenceNumber (optional), an internal or reference number of the Observation
* Size_alpha (recommended), the Bounding box size including the observation 
                            in Right Ascension
* Size_delta (recommended), the Bounding box size including the observation 
                            in Declination
* PixelSize (recommended),  the Pixel size measured in sky units.Actual unit
                            (arsec,arcmin,deg)is given in the FIELD definition.
* Origin (optionnal),       the Organism who provided the data.
* OriginalCoding (optional), the image format provided 
* AvailableCodings (optional), for the possible codings of these data in request
* alpha(recommended),         the RA Position of center
* delta(recommended),         the DEC Position of center
* Position Angle,          the Position Angle of the Observation Y axis East of 
                              North

The meaning of all the attributes will be clarified by an
annotated example, which will be available soon.


DATA LOCATION
----------------------------------------------------

The data location parameters are set within the StorageMapping 
<RESOURCE> element. The attribute (<FIELD>) is Location, 
the value of which can be a file path, an URL or a GLU mark. 
The file path is intended for referring to local files only.
Each file path must be preceded by  "file:"
URL and Glu Marks are intended to provide access to remote files. 
Glu marks are prececed by "glu:" The Glu marks allow for inclusion
of parametrized URL templates. To enable this facility the service 
needs to be registered in a GLU database.



 


______________________________________________________________________
Annotated exemple

<?xml version="1.0"?>
<!DOCTYPE VOTABLE SYSTEM "http://us-vo.org/xml/VOTable.dtd">
<VOTABLE ID="v1.0">
 <DEFINITIONS>
 <COOSYS ID="J2000" system="eq_FK5" equinox="2000"/>
 </DEFINITIONS>
<!-- The info elements recall the request that we are answering...-->
 <INFO ID="position" value="53.116290 -27.808750"/>
 <INFO ID="radius" value="0.250000deg" />
 <INFO ID="type"  value="ObservingProgram,band,ProcessedObservation">
<!-- The ObservingProgram resource is the root node of our tree-->
<!-- Several Observing Programs resources can be appended in the same document...-->

 <RESOURCE name="ObservingProgram"  >
  <INFO ID="OPtype" value="survey"/>
  <!-- A resource has a table section which contains the specific attributes-->
  <!-- of the corresponding IDHA model object-->
  <TABLE ID="ObservingProgram">
    <DESCRIPTION>
      This is a few resource information for the
      ObservingProgram 
    </DESCRIPTION>
    <!-- Each field in this table is associated with an attribute of-->
    <!-- the model object  associated with the current resource "ObservingProgram"-->
    <FIELD ID="Name" name="Name" datatype="char" ucd="ID_SURVEY">
      <DESCRIPTION> ObservingProgram Name </DESCRIPTION>
    </FIELD>
    <FIELD ID="Organisation" name="Organisation" datatype="char" ucd="CURATOR">
      <DESCRIPTION> Name of Organisation(s) 
          performing Observing Program
      </DESCRIPTION>
    </FIELD>
    <FIELD ID="Begin" name="beginning_date" datatype="char">
     <DESCRIPTION> Begin date of the survey
     </DESCRIPTION>
    </FIELD>
    <FIELD ID="End" name="end date" datatype="char">
     <DESCRIPTION> End date of Observing program
     </DESCRIPTION>
    </FIELD>
    <FIELD ID="SpectralDomain" name="SpectralCoverageName" datatype="char">
     <DESCRIPTION> General spectral domain (Optical X-ray ...)
     </DESCRIPTION>
    </FIELD>
    <!-- The data elements can contain as many lines we have instances of the-->
    <!-- current class. However if the current instance has children in-->
    <!-- the tree: in that case we will only write one line, include the--> 
    <!-- children as new resources and then write later in the VOTABLE a -->
    <!-- new ressource with  the same name and another table-->
    <DATA><TABLEDATA>
      <TR><TD>GOODS-WFI</TD><TD>ESO</TD><TD>01/01/2002</TD><TD>31/12/2002</TD><TD>Optical</TD></TR>
    </TABLEDATA></DATA>
  </TABLE>
     <!-- We start a new resource (here Observation_Group) before closing the-->
     <!--  previous one.-->
     <RESOURCE name="Observation_Group" >
      <!-- The value attribute of the info element gives here the list-->
      <!-- of constrained attributes-->
     <INFO name ="OGtype" value="filter,epoch"/>
       <TABLE ID="Observation_Group">
        <DESCRIPTION> This is a subset of images 
          belonging to a survey, an experiment, 
          and organised according to the same 
          common criterion. e.g. exemple of 
          criterion: color or wavelength, 
          polarimetry, etc... exemple of 
          Observation_Group: POSSII band J, 
          DENIS band K, etc.. 
        </DESCRIPTION>
        
        <FIELD ID="Selection_Criterion" name="Selection_Criterion" datatype="char">
          <DESCRIPTION> Sampled Parameter
          </DESCRIPTION>
        </FIELD>
        <FIELD ID="Selection-Range" name="Selection-Range" datatype="char">
           <DESCRIPTION> Constraint on sampled parameter
           </DESCRIPTION>
        </FIELD>
        <!-- the first field gives the constrained parameter-->
        <!-- the second one is the constraint. a simple value-->
        <!-- like here is for a match to this value-->
        <!-- The observing group here is the conjonction of-->
        <!-- the filter and the epoch restrictions.-->
        <!-- It is possible to add other criteria as new lines in this table-->
        <!-- It is also possible to have criteria in another order-->
        <!-- Observation_Groups with the same constraint on the first -->
        <!-- criterium will be  grouped in the same node by the metadata tree-->
        <!-- browser.One can have as many levels of grouping in the Metadata -->
        <!-- tree than we have lines in the table -->
        <DATA><TABLEDATA>
          <TR><TD>"filter"</TD><TD>ICLWP</TD></TR>
          <TR><TD>"epoch"</TD><TD>epoch1</TD></TR>
        </TABLEDATA></DATA>
       </TABLE>
       <!-- The filter ressource included in the Observation_Group-->
       <!-- gives details on the Filter characteristics for the-->
       <!-- filter(s) used for the current band-->
         <RESOURCE name="Filter">
           <TABLE ID="Filter">
            <DESCRIPTION> 
                Description of the filter characteristics
            </DESCRIPTION>
            <FIELD ID="Minimal_wavelength" name="Minimal_wavelength" datatype="float" precision="F7" width="11" ucd="SPECT_WAVELENGTH" unit = "um">
              <DESCRIPTION> Minimal wavelength of the filter bandpath
              </DESCRIPTION>
            </FIELD>
            <FIELD ID="Maximal_wavelength" name="Maximal_wavelength" datatype="float" precision="F7" width="11" ucd="SPECT_WAVELENGTH" unit = "um">
               <DESCRIPTION> Maximal wavelength of the filter bandpath
               </DESCRIPTION>
            </FIELD>
            <FIELD ID="Effective_wavelength" name="Effective_wavelength" datatype="float" precision="F7" width="11" ucd="SPECT_WAVELENGTH " unit = "um">
               <DESCRIPTION> Effective wavelength of the filter bandpath
               </DESCRIPTION>
            </FIELD>
            <FIELD ID="Identifier" name="Identifier" datatype="char" ucd="ID_FILTER">
               <DESCRIPTION> Reference ID of the filter, according to the Instruments settings.
               </DESCRIPTION>
            </FIELD>
            <FIELD ID="Filter_Name" name="Filter_Name" datatype="char" ucd="ID_FILTER">
               <DESCRIPTION> Usual name of the band observed (ex: 2MASS K,SERC J,..)
               </DESCRIPTION>
            </FIELD>
            <DATA><TABLEDATA>
              <TR><TD>0.783000</TD><TD>1.001000</TD><TD></TD><TD>ICLWP</TD><TD></TD></TR>
            </TABLEDATA></DATA>
           </TABLE>
         </RESOURCE>
         <!-- The ProcessedObservation Resource also included-->
         <!-- in the Observation_Group-->
         <!-- describes each of the observations in the group -->
         <!-- included in the cone search-->
         <RESOURCE name="ProcessedObservation">
            <TABLE ID="ProcessedObservation">
              <DESCRIPTION>
                 This resource describes list of processed observations 
              </DESCRIPTION>
              <FIELD ID="Observation_Name" name="Observation_Name" datatype="char" ucd="ID_IMAGE">
                <DESCRIPTION>
                 "Name of the Observation" 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="ReferenceNumber" name="ReferenceNumber" datatype="char" ucd="ID_IMAGE">
                <DESCRIPTION>
                  "Reference Number of the Image" 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="Size_alpha" name="Size_alpha" datatype="float" precision="7" width="11" unit="deg" ucd="INST_DET_SIZE">
                <DESCRIPTION>
                   Observation range in alpha (angular) 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="Size_delta" name="Size_delta" datatype="float" precision="F7" width="11" unit="deg" ucd="INST_DET_SIZE">
                <DESCRIPTION>
                   Observation range in delta (angular) 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="PixelSize" name="Angular Pixel Size"  datatype="float" unit ="deg">
                <DESCRIPTION>
                   Pixel size measured in sky units
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="Origin" name="Origin" datatype="char">
                 <DESCRIPTION>
                   Data provider references
                 </DESCRIPTION>
              </FIELD>
              <FIELD ID="OriginalCoding" name="OriginalCoding" datatype="char">
                 <DESCRIPTION>
                   Image coding provided by the data producer
                 </DESCRIPTION>
              </FIELD>
              <FIELD ID="AvailableCodings" name="AvailableCodings" datatype="char">
                 <DESCRIPTION>
                  Codings which may be  produced on the fly
                 </DESCRIPTION>
              </FIELD>
              <FIELD ID="alpha" name="CentralPoint_RA" ucd="POS_EQ_RA_MAIN"  datatype="float" precision="F7" width="11" unit="deg">
                <DESCRIPTION>
                    Position of center	
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="delta" name="CentralPoint_DEC" ucd="POS_EQ_DEC_MAIN"  datatype="float" precision="F7" width="11" unit="deg">
                <DESCRIPTION>
                    Position of center	
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="date" name="DateAndTime"  datatype="char">
                <DESCRIPTION>
                    Observation date
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="AP" name="Position Angle"  datatype="float" precision="F7"  width="11" unit="deg">
                <DESCRIPTION>
                   Position Angle of the Y axis
                </DESCRIPTION>
              </FIELD>
             <DATA><TABLEDATA>
             <!-- Here we generally find several lines,  one by observation-->
               <TR><TD>DEEP2C-FI</TD><TD></TD><TD>0.655380</TD><TD>0.688248</TD><TD>0.000066</TD><TD>ESO</TD><TD>FITS</TD><TD>FITS</TD><TD>53.119485</TD><TD>-27.803630</TD><TD>1999-11-05</TD><TD>0.001375</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
         <!-- The storage Mapping ressource contains as many lines as the-->
         <!-- previous "Processed Observation" one It gives implementation-->
         <!-- details for the Observation. -->
         <!-- the link between records is made by the common Observation_Name-->
         <!-- field (here the Observation_Name field appears as a reference -->
         <!-- to the field defined in the "processedObservation" ressource-->
         <RESOURCE name="StorageMapping">
            <TABLE ID="StorageMapping">
              <DESCRIPTION>
                 This resource describes list of processed observations 
              </DESCRIPTION>
              <FIELD ref="Observation_Name" >
              </FIELD>
              <FIELD ID="Cutout" name="Organisation"  datatype="char">
                <DESCRIPTION>
                    Status of cutout availability 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="number" name="NumberOfPatches"  datatype="int">
                <DESCRIPTION>
                     Number of subimages
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="size" name="Maximum size"  datatype="int">
                <DESCRIPTION>
                   Maximum size 
                </DESCRIPTION>
              </FIELD>
              <FIELD ID="Location" name="Location" datatype="char">
                 <DESCRIPTION>
                     File location
                 </DESCRIPTION>
              </FIELD> 
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FI</TD><TD>CUTOUTS</TD><TD>25</TD><TD>2048</TD><TD>file:/GOODS/DEEP2C-FI.fits</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
     </RESOURCE>
     <RESOURCE name="Observation_Group" >
     <INFO name ="OGtype" value="filter,epoch"/>
       <TABLE ref="Observation_Group">
        <DATA><TABLEDATA>
          <TR><TD>"filter"</TD><TD>RC162</TD></TR>
          <TR><TD>"epoch"</TD><TD>epoch1</TD></TR>
        </TABLEDATA></DATA>
       </TABLE>
         <RESOURCE name="Filter" >
           <TABLE ref="Filter">
            <DATA><TABLEDATA>
              <TR><TD>0.571000</TD><TD>0.731000</TD><TD></TD><TD>RC162</TD><TD></TD></TR>
            </TABLEDATA></DATA>
           </TABLE>
         </RESOURCE>
         <RESOURCE name="ProcessedObservation">
            <TABLE ref="ProcessedObservation">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FR</TD><TD></TD><TD>0.630168</TD><TD>0.641256</TD><TD>0.000066</TD><TD>ESO</TD><TD>FITS</TD><TD>FITS</TD><TD>53.107341</TD><TD>-27.793466</TD><TD>2000-10-26</TD><TD>0.007780</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
         <RESOURCE name="StorageMapping">
            <TABLE ref="StorageMapping">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FR</TD><TD>CUTOUTS</TD><TD>25</TD><TD>2048</TD><TD
>/GOODS/DEEP2C-FR.fits</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
     </RESOURCE>
     <RESOURCE name="Observation_Group" >
     <INFO name ="OGtype" value="filter,epoch"/>
       <TABLE ref="Observation_Group">
        <DATA><TABLEDATA>
          <TR><TD>"filter"</TD><TD>V89</TD></TR>
          <TR><TD>"epoch"</TD><TD>epoch1</TD></TR>
        </TABLEDATA></DATA>
       </TABLE>
         <RESOURCE name="Filter" >
           <TABLE ref="Filter">
            <DATA><TABLEDATA>
              <TR><TD>0.495000</TD><TD>0.585000</TD><TD></TD><TD>V89</TD><TD></TD></TR>
            </TABLEDATA></DATA>
           </TABLE>
         </RESOURCE>
         <RESOURCE name="ProcessedObservation">
            <TABLE ref="ProcessedObservation">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FV</TD><TD></TD><TD>0.634854</TD><TD>0.620532</TD><TD>0.000066</TD><TD>ESO</TD><TD>FITS</TD><TD>FITS</TD><TD>53.109618</TD><TD>-27.802574</TD><TD>2000-10-26</TD><TD>0.006580</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
         <RESOURCE name="StorageMapping">
            <TABLE ref="StorageMapping">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FV</TD><TD>CUTOUTS</TD><TD>25</TD><TD>2048</TD><TD
>/GOODS/DEEP2C-FV.fits</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
     </RESOURCE>
     <RESOURCE name="Observation_Group" >
     <INFO name ="OGtype" value="filter,epoch"/>
       <TABLE ref="Observation_Group">
        <DATA><TABLEDATA>
          <TR><TD>"filter"</TD><TD>U38</TD></TR>
          <TR><TD>"epoch"</TD><TD>epoch1</TD></TR>
        </TABLEDATA></DATA>
       </TABLE>
         <RESOURCE name="Filter" >
           <TABLE ref="Filter">
            <DATA><TABLEDATA>
              <TR><TD>0.344000</TD><TD>0.382000</TD><TD></TD><TD>U38</TD><TD></TD></TR>
            </TABLEDATA></DATA>
           </TABLE>
         </RESOURCE>
         <RESOURCE name="ProcessedObservation">
            <TABLE ref="ProcessedObservation">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FU</TD><TD></TD><TD>0.625284</TD><TD>0.639474</TD><TD>0.000066</TD><TD>ESO</TD><TD>FITS</TD><TD>FITS</TD><TD>53.105229</TD><TD>-27.797327</TD><TD>2000-10-26</TD><TD>0.008895</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
         <RESOURCE name="StorageMapping">
            <TABLE ref="StorageMapping">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FU</TD><TD>CUTOUTS</TD><TD>25</TD><TD>2048</TD><TD
>/GOODS/DEEP2C-FU.fits</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
     </RESOURCE>
     <RESOURCE name="Observation_Group" >
     <INFO name ="OGtype" value="filter,epoch"/>
       <TABLE ref="Observation_Group">
        <DATA><TABLEDATA>
          <TR><TD>"filter"</TD><TD>B99</TD></TR>
          <TR><TD>"epoch"</TD><TD>epoch1</TD></TR>
        </TABLEDATA></DATA>
       </TABLE>
         <RESOURCE name="Filter" >
           <TABLE ref="Filter">
            <DATA><TABLEDATA>
              <TR><TD>0.406000</TD><TD>0.506000</TD><TD></TD><TD>B99</TD><TD></TD></TR>
            </TABLEDATA></DATA>
           </TABLE>
         </RESOURCE>
         <RESOURCE name="ProcessedObservation">
            <TABLE ref="ProcessedObservation">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FB</TD><TD></TD><TD>0.601986</TD><TD>0.554598</TD><TD>0.000066</TD><TD>ESO</TD><TD>FITS</TD><TD>FITS</TD><TD>53.120442</TD><TD>-27.808151</TD><TD>2000-10-26</TD><TD>0.000870</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
         <RESOURCE name="StorageMapping">
            <TABLE ref="StorageMapping">
             <DATA><TABLEDATA>
               <TR><TD>DEEP2C-FB</TD><TD>CUTOUTS</TD><TD>25</TD><TD>2048</TD><TD
>/GOODS/DEEP2C-FB.fits</TD></TR>
             </TABLEDATA></DATA>
            </TABLE>
         </RESOURCE>
     </RESOURCE>
 </RESOURCE>
</VOTABLE>

-------------------------------------------------------------------------------

Some original metadata for that = FITS HEADER for the blue image
SIMPLE  =                    T          / file does conform to FITS standard
BITPIX  =                  -32          / number of bits per data pixel
NAXIS   =                    2          / number of data axes
NAXIS1  =                 9121          / length of data axis 1
NAXIS2  =                 8403          / length of data axis 2
MJD-OBS =       51843.31944900          / Obs start 2000-10-26T07:40:00.383 (day
ORIGIN  = 'EIS     '                    / ESO Imaging Survey
RA      =            53.439926          / 03:33:45.5 RA (J2000) at start (deg)
DEC     =            -27.80982          / -27:48:35 DEC (J2000) at start (deg)
DATE    = '2000-10-26T07:42:49'         / UT date and time when file was written
DATE-OBS= '2000-10-26T07:40:00.383'     / UT date and time of observation at sta
LST     =            19023.266          / 05:17:03.27 LST at start (sec)
UTC     =            27599.977          / 07:39:59.98 UTC at start (sec)
RADECSYS= 'FK5     '                    / Coordinate reference frame
OBJECT  = 'deep2c_FB'                   / Object name.
CRVAL1  =            53.122059          / [deg] X reference coordinate value
CRVAL2  =             -27.8132          / [deg] Y reference coordinate value
CTYPE1  = 'RA---COE'                    / Type of Sky projection
CTYPE2  = 'DEC--COE'                    / Sky projection.
CD1_1   = -6.60000000000000E-05         / [deg/pixel] Matrix rotation
CD1_2   =                  -0.          / [deg/pixel] Matrix rotation
CD2_1   =                  -0.          / [deg/pixel] Matrix rotation
CD2_2   = 6.60000000000000E-05          / [deg/pixel] Matrix rotation
TELESCOP= 'ESO-2.2 '                    / Telescope name.
INSTRUME= 'WFI     '                    / Instrument name.
EQUINOX =                2000.          / [year] Projection reference.
HANGLE  =     2.6027026000E+01          / [deg] Hour angle. Sud = 0.
FILTER  = 'B99     '                    / Filter.
RON     =     4.5000000000E+00          / [e-] Read Out Noise.
CRPIX1  =                4536.          / [pixel] X reference pixel
CRPIX2  =                4125.          / [pixel] Y reference pixel
JDAY    =    2451843.826081000          / [day] Jday of observation.
AIRMASS =    1.101322000000000          / [1/cos(zenith_distance)] Airmass.
EXPTIME =     1.00000000000000          / [sec] Exposure time.
EPOCH   =     2000.81781300000          / [year]
FLXSCALE=         1.0000000000          / Relative Flux Scale
GAIN    =     49093.6940510000          / [e-/ADU] Gain.
TOT-EXPT=             24546.85          / [sec] Total cumulative exposure
TOT-IMAG=                   30          / Total number of stacked images
PROJP1  =     -2.781320000E+01          / COE
PROJP2  = 0.00000000000000E+00          / COE
ZP      =             24.29485          / zero point
ZP_ERR  =                0.029          / error in the zero point
SEE_IMA =                 1.02          / seeing measured in the image
P_ID    =                   24          / EIS Product ID
DPR_TYPE= 'SCIENCE '                    / Type of image data
COMMENT --------------------------------------------------------
COMMENT This FITS file is part of the ESO Imaging Survey (EIS)
COMMENT data release or has been produced by one of the EIS
COMMENT on-line servers. The data is under copyright of ESO.
COMMENT In using this data for the preparation of scientific or
COMMENT other publications proper acknowledgement should be
COMMENT given to ESO and the EIS project.
COMMENT
COMMENT c) European Southern Observatory, 2001
COMMENT --------------------------------------------------------
COMMENT --------------------------------------------------------
COMMENT This FITS file is part of the ESO Imaging Survey (EIS)
COMMENT data release or has been produced by one of the EIS
COMMENT on-line servers. The data is under copyright of ESO.
COMMENT In using this data for the preparation of scientific or
COMMENT other publications proper acknowledgement should be
COMMENT given to ESO and the EIS project.
COMMENT
COMMENT c) European Southern Observatory, 2001
COMMENT --------------------------------------------------------
COMMENT FTU-1.43/2001-03-05T14:49:25/split.ftt
HISTORY FTU-1.43/2001-03-05/ADD: DPR_TYPE
HISTORY FTU-1.43/2001-03-05/ADD: DPR_TYPE





=====================================================================
Francois   Bonnarel               Observatoire Astronomique de Strasbourg
CDS (Centre de donnees          11, rue de l'Universite
astronomiques de Strasbourg)    F--67000 Strasbourg (France)

Tel: +33-(0)3 90 24 24 11       WWW: http://cdsweb.u-strasbg.fr/people/fb.html
Fax: +33-(0)3 90 24 24 25       E-mail: bonnarel at astro.u-strasbg.fr
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