Data set metadata examples

These are attempts to describe some of the DataSets mentioned in the Brown Dwarf and Deep Field science cases (see the BrownDwarfMetadataList in BrownDwarfRegistryRequirements and the metadata list in DeepFieldSurveysRegistryRequirements using a draft [[http://wiki.astrogrid.org/bin/view/Astrogrid/DataServiceSchema][Data Service Schema]]. This is a Registry level description, to be supplemented by the DataSets own UCDs in the header and columns.

NB some things I have calculated and these values are only for illustration - refer to the references above to do anything real! In any case the values are generous limits to avoid excluding borderline DataSets.

Both these DataSets are really suites of data sets containg both catalogues and images.

2MASS

CONTENT
"content"               string       
"facility"              "Mt. Hopkins, AZ", "CTIO, Chile" 
"instrument"            "three-channel camera, each channel consisting of a 256x256 array of HgCdTe detectors"  should have a short name? 
"format"                "VOTable", "ascii", "FITS"
"briefsummary"
"[[http://www.ipac.caltech.edu/2mass/releases/allsky/doc/sec1_1.html][html link]]"
"tablenrows"            "1000"      This is the size of Vizier catalogue - only a partial release?
"tablencols"            "43"        This is the size of Vizier catalogue - only a partial release?
"tablesize"             "" tbd (bytes)
"ndimdatasetsizemin"    "512 x 1024"    (pixels x pixels)
"ndimdatasetsizemax"    "512 x 698"     (pixels x pixels)
"nndimdatasets"         "4,121,439"     
"type"                  "archive", "survey", "catalogue"
"subjectkeyword"        "Null"

COVERAGE
"coverage"              string   
"wavelengthrange"       "ir"
"wavelengthshort"       decimal         (metres)
"wavelengthlong"        decimal         (metres)
"ramin"                 0               (degrees)
"ramax"                 360             (degrees)
"decmin"                -90             (degrees)
"decmax"                +90             (degrees)
"sensitvity"            "16.8"          (J mag)
                        "16.1"          (H mag)
                        "15.3"          (K mag)
 This is their lower limit, only complete to 1 mag brighter.  Or for simplicity just use: 
"sensitivity"           "1e-3"          (Jy)
"startdate"             "2450601"       (JD) 
"enddate"               "2451969"       (JD) 
"angularfraction"       "0.99998"       (dimensionless fraction)
"spectralfraction"      "tbd"           (dimensionless fraction)
"temporalfraction"      "0.5"           (dimensionless fraction) 
probably meaningless and should be NaN for a survey unless regions were systematically repeatedly scanned
"sourcedensity"         "11417"         (counts per square degree)

RESOLUTION
"resolution"            string         
"angularresolution"     "2"             (arcsec)
"spectralresolution"    "tbd"           (dimensionless fraction)
"temporalresolution"    "tbd"           (sec)

DATAQUALITY
"dataquality"           string          (see elements following)*
"astrometryerror"       "0.3"           (arcsec)  I think this is a lower limit, unclear if it includes all systematic errors
"photometryerror"       "0.01"          (dimensionless fraction) 
"timingerror"           "tbd"           (dec)

MERLIN+VLA HDF(N)

CONTENT
"content"               string          (see elements following)
"facility"              "JBO", "NRAO"
"instrument"            "MERLIN", "VLA"
"format"                "VOTable", "ascii", "FITS"
"briefsummary"
"[[http://vizier.u-strasbg.fr/viz-bin/Cat?B/avo.rad][html link]]"
"tablenrows"            "92"  
"tablencols"            "32"  Counting each element of RA and DEC separately 
"tablesize"             "tbd"           (bytes)         
"ndimdatasetsizemin"    "1024 x 1024"   (pixels x pixels)
"ndimdatasetsizemax"    "8096 x 8096"   (pixels x pixels)
"nndimdatasets"         "66"            
"type"                  "survey", "catalogue"
"subjectkeyword"        "Galaxies"


COVERAGE
"coverage"              string   
"wavelengthrange"       "radio"
"wavelengthshort"       "0.209"         (metres)
"wavelengthlong"        "0.220"         (metres)
"ramin"                 "189.172"       (degrees)
"ramax"                 "189.239"       (degrees)
"decmin"                "62.145"        (degrees)
"decmax"                "62.288"        (degrees)
"sensitvity"            "27e-6"         (Jansky)
"startdate"             "2450389"       (JD) 
"enddate"               "2450569"       (JD) 
"angularfraction"       "1.0"           (dimensionless fraction)
"spectralfraction"      "0.625"         (dimensionless fraction)
"temporalfraction"      "0.11"          (dimensionless fraction)
"sourcedensity"         "4500"          (counts per square degree)


RESOLUTION
"resolution"            string 
"angularresolution"     "0.2"           (arcsec)
"spectralresolution"    "0.35e-3"       (dimensionless fraction)
"temporalresolution"    "NaN"           (sec)

DATAQUALITY
"dataquality"           string          
"astrometryerror"       "0.05"          (arcsec)
"photometryerror"       "4e-6"          (Jy)
"timingerror"            "NaN"          (sec)

-- AnitaRichards - 09 May 2003