alerce_tap.ztf_divo://x-unregistred/alerce_tap/multisurvey_lowercase/ztf_dataqualityALeRCE (Automatic Learning for the Rapid Classification of Events)ALeRCE Teamhttps://tap.alerce.online/favicon.png2026-04-11T22:13:50ZALeRCE Team

Beauchef 851, Edificio Norte, piso 6. Santiago, Chile.

alerce.broker@gmail.comastronomy, objectssurveystransientstime-series Detailed data quality metrics for ZTF detections including image position, PSF-fit quality (chi-square, FWHM), SExtractor properties, pixel statistics, photometric calibration parameters, and signal-to-noise measurements.http://tap.alerce.online/tableinfo/alerce_tap.ztf_dataqualityalerce_tap Multi-survey astronomical object catalog containing astrometric and statistical information from multiple surveys. This table provides aggregated properties for astronomical objects including position, detection statistics, and temporal coverage.alerce_tap.ztf_dataquality Detailed data quality metrics for ZTF detections including image position, PSF-fit quality (chi-square, FWHM), SExtractor properties, pixel statistics, photometric calibration parameters, and signal-to-noise measurements.oidUnique identifier for this objectmeta.id;srclongindexedprimarymeasurement_idUnique identifier for the subtraction candidatemeta.idlongindexedprimaryxposX-image position of candidate on CCDpixpos.cartesian.xfloatnullableyposY-image position of candidate on CCDpixpos.cartesian.yfloatnullablechipsfReduced chi-square for PSF-fitstat.fit.goodnessfloatnullableskyLocal sky background estimate [DN]instr.skyLevelfloatnullablefwhmFull Width Half Maximum assuming a Gaussian core, from SExtractorpixinstr.obsty.seeingfloatnullableclasstarStar/Galaxy classification score from SExtractorsrc.class.starGalaxyfloatnullablemindtoedgeDistance to nearest edge in imagepixphys.angSizefloatnullableseeratioRatio: difffwhm / fwhmstat.fit.goodnessfloatnullableaimageWindowed profile RMS along major axis from SExtractorpixphys.angSize.smajAxisfloatnullablebimageWindowed profile RMS along minor axis from SExtractorpixphys.angSize.sminAxisfloatnullableaimageratRatio: aimage / fwhmarith.ratiofloatnullablebimageratRatio: bimage / fwhmarith.ratiofloatnullablennegNumber of negative pixels in a 5 x 5 pixel stampmeta.numberintnullablenbadNumber of prior-tagged bad pixels in a 5 x 5 pixel stampmeta.numberintnullablesumratRatio: sum(pixels) / sum(abs(pixels)) in a 5 x 5 pixel stamp where stamp is first median-filtered to mitigate outliersarith.ratiofloatnullablescorrPeak-pixel signal-to-noise ratio in point source matched-filtered detection imagestat.correlationdoublenullabledsnrmsRatio: D/stddev(D) on event position where D = difference imagestat.stdevfloatnullablessnrmsRatio: S/stddev(S) on event position where S = image of convolution: D (x) PSF(D)stat.stdevfloatnullablemagzpsciMagnitude zero point for photometry estimatesmagphot.calibfloatnullablemagzpsciuncMagnitude zero point uncertainty (in magzpsci)magstat.error;phot.calibfloatnullablemagzpscirmsRMS (deviation from average) in all differences between instrumental photometry and matched photometric calibrators from science image processingmagstat.stdev;phot.calibfloatnullablenmatchesNumber of PS1 photometric calibrators used to calibrate science image from science image processingmeta.numberintnullableclrcoeffColor coefficient from linear fit from photometric calibration of science imagearith.factorfloatnullableclrcouncColor coefficient uncertainty from linear fit (corresponding to clrcoeff)stat.error;arith.factorfloatnullablezpclrcovCovariance in magzpsci and clrcoeff from science image processing [mag^2]stat.covariancefloatnullablezpmedMagnitude zero point from median of all differences between instrumental photometry and matched photometric calibrators from science image processingmagphot.calib;stat.medianfloatnullableclrmedMedian color of all PS1 photometric calibrators used from science image processing: for filter (fid) = 1, 2, 3, PS1 color used = g-r, g-r, r-i respectivelystat.medianfloatnullableclrrmsRMS color (deviation from average) of all PS1 photometric calibrators used from science image processingstat.stdevfloatnullableexptimeIntegration time of camera exposurestime.duration;obs.exposurefloatnullablecreated_dateDate record was createdtime.creationcharnullable