CcdVisit

Metadata about the nine individual CCD images for each Visit in the DP1 LSSTComCam dataset.

Columns

name datatype description unit nullable ivoa:ucd tap:column_index tap:principal votable:arraysize votable:xtype length precision
physical_filter char ID of physical filter, the filter associated with a particular instrument. true 0 * 32
band char Name of the band used to take the visit where this source was measured. Abstract filter that is not associated with a particular instrument. true 1 * 1
ra double Right Ascension of Ccd center. deg true 1
dec double Declination of Ccd center. deg true 1
pixelScale float Measured detector pixel scale. arcsec/pixel true 0
zenithDistance float Zenith distance at observation mid-point. deg true 1
expTime double Spatially-averaged duration of visit, accurate to 10ms. s true 1
zeroPoint float Zero-point for the Ccd, estimated at Ccd center. mag true 0
psfSigma float PSF model second-moments determinant radius (center of chip) pixel true 1
skyBg float Average sky background. adu true 0
skyNoise float RMS noise of the sky background. adu true 0
astromOffsetMean double Mean offset of astrometric calibration matches (arcsec) arcsec true 0
astromOffsetStd double Standard deviation of offsets of astrometric calibration matches (arcsec) arcsec true 0
nPsfStar int Number of stars used for PSF model true 0
psfStarDeltaE1Median double Median E1 residual (starE1 - psfE1) for psf stars true 0
psfStarDeltaE2Median double Median E2 residual (starE2 - psfE2) for psf stars true 0
psfStarDeltaE1Scatter double Scatter (via MAD) of E1 residual (starE1 - psfE1) for psf stars true 0
psfStarDeltaE2Scatter double Scatter (via MAD) of E2 residual (starE2 - psfE2) for psf stars true 0
psfStarDeltaSizeMedian double Median size residual (starSize - psfSize) for psf stars (pixel) pixel true 0
psfStarDeltaSizeScatter double Scatter (via MAD) of size residual (starSize - psfSize) for stars (pixel) pixel true 0
psfStarScaledDeltaSizeScatter double Scatter (via MAD) of size residual scaled by median size squared true 0
psfTraceRadiusDelta double Delta (max - min) of model psf trace radius values evaluated on a grid of unmasked pixels (pixel) pixel true 0
psfApFluxDelta double Delta (max - min) of model psf aperture flux (with aperture radius of max(2, 3*psfSigma)) values evaluated on a grid of unmasked pixels true 0
psfApCorrSigmaScaledDelta double Delta (max - min) of psf flux aperture correction factors scaled (divided) by the psfSigma evaluated on a grid of unmasked pixels true 0
maxDistToNearestPsf double Maximum distance of an unmasked pixel to its nearest model psf star (pixel) pixel true 0
ccdVisitId long Primary key (unique identifier). true 0
visitId primary key foreign key indexed long Reference to the corresponding entry in the Visit table. true meta.id.parent;obs 2 1
detector primary key indexed long Detector ID. A detector associated with a particular instrument (not an observation of that detector). true 1
seeing double Mean measured FWHM of the PSF. arcsec true 1
skyRotation double Sky rotation angle. deg true 0
expMidpt timestamp Midpoint time for exposure at the fiducial center of the focal plane array. TAI, accurate to 10ms. true 6 0 * timestamp 6
expMidptMJD double Midpoint time for exposure at the fiducial center of the focal plane array in MJD. TAI, accurate to 10ms. d true time.epoch;obs.exposure 5 1
obsStart timestamp Start of the visit, TAI, accurate to 10ms. true 0 * timestamp 6
obsStartMJD double Start of the exposure in MJD, TAI, accurate to 10ms. d true time.start;obs.exposure 7 0
darkTime double Average dark current accumulation time, accurate to 10ms. s true 0
xSize long Number of columns in the image. pixel true 0
ySize long Number of rows in the image. pixel true 0
llcra double Right Ascension of lower left corner. deg true 0
llcdec double Declination of lower left corner. deg true 0
ulcra double Right Ascension of upper left corner. deg true 0
ulcdec double Declination of upper left corner. deg true 0
urcra double Right Ascension of upper right corner. deg true 0
urcdec double Declination of upper right corner. deg true 0
lrcra double Right Ascension of lower right corner. deg true 0
lrcdec double Declination of lower right corner. deg true 0
effTime double Effective time metric s true 0
effTimePsfSigmaScale double Effective time metric -- PSF size component true 0
effTimeSkyBgScale double Effective time metric -- Sky background component true 0
effTimeZeroPointScale double Effective time metric -- Throughput component true 0
magLim double 5-sigma limiting magnitude mag true 1

Indexes

Index Definition Description
idx_CcdVisit_visitId visitId Non-unique index on visitId column; accelerates retrieval of data for all detectors for a visit
idx_CcdVisit_visitId_detector visitId, detector Unique index on visit and detector columns in CcdVisit table

Constraints

Constraint Type Definition Description
fk_CcdVisit_Visit ForeignKey
Columns: visitId
References: Visit.visit
 Link a Visit to the CCD-level images it contains