N 
Name  Schema Table  Database  Description  Type  Length  Unit  Default Value  Unified Content Descriptor 
name 
[nspid]FSstars 
WSA NonSurvey 
reference name of field 
varchar 
16 

NONE 
???? 
name 
[nspid]Filter 
WSA NonSurvey 
The name of the filter, eg. "MKO J", "WFCAM Y" etc. 
varchar 
16 


NOTE 
name 
[nspid]RequiredMosaic 
WSA NonSurvey 
Name of the mosaiced product 
varchar 
64 


?? 
name 
[nspid]RequiredStack 
WSA NonSurvey 
Name of the stacked product 
varchar 
64 


?? 
name 
[nspid]Survey 
WSA NonSurvey 
The short name for the survey 
varchar 
128 


?? 
nbhAperMag3 
[nspid]Source 
WSA NonSurvey 
Default point source Nbh aperture corrected mag (2.0 arcsec aperture diameter) If in doubt use this flux estimator 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhAperMag3Err 
[nspid]Source 
WSA NonSurvey 
Error in default point source Nbh mag (2.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhAperMag4 
[nspid]Source 
WSA NonSurvey 
Point source Nbh aperture corrected mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhAperMag4Err 
[nspid]Source 
WSA NonSurvey 
Error in point source Nbh mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhAperMag6 
[nspid]Source 
WSA NonSurvey 
Point source Nbh aperture corrected mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhAperMag6Err 
[nspid]Source 
WSA NonSurvey 
Error in point source Nbh mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhaStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c0 from FerreiraLopes & Cross 2017, Eq. 18, in fit to astrometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhaStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c0 from FerreiraLopes & Cross 2017, Eq. 18, in fit to photometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhbestAper 
[nspid]Variability 
WSA NonSurvey 
Best aperture (16) for photometric statistics in the Nbh band 
int 
4 

9999 

Aperture magnitude (16) which gives the lowest RMS for the object. All apertures have the appropriate aperture correction. This can give better values in crowded regions than aperMag3 (see Irwin et al. 2007, MNRAS, 375, 1449) 
nbhbStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c1 from FerreiraLopes & Cross 2017, Eq. 18, in fit to astrometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhbStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c1 from FerreiraLopes & Cross 2017, Eq. 18, in fit to photometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhchiSqAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Goodness of fit of Strateva function to astrometric data in Nbh band 
real 
4 

0.9999995e9 
stat.fit.goodness 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhchiSqpd 
[nspid]Variability 
WSA NonSurvey 
Chi square (per degree of freedom) fit to data (mean and expected rms) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhchiSqPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Goodness of fit of Strateva function to photometric data in Nbh band 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhClass 
[nspid]Source 
WSA NonSurvey 
discrete image classification flag in Nbh 
smallint 
2 

9999 
CLASS_MISC 
nbhClassStat 
[nspid]Source 
WSA NonSurvey 
N(0,1) stellarnessofprofile statistic in Nbh 
real 
4 

0.9999995e9 
STAT_PROP 
nbhcStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c2 from FerreiraLopes & Cross 2017, Eq. 18, in fit to astrometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhcStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c2 from FerreiraLopes & Cross 2017, Eq. 18, in fit to photometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhDeblend 
[nspid]Source 
WSA NonSurvey 
placeholder flag indicating parent/child relation in Nbh 
int 
4 

99999999 
CODE_MISC 
This CASU pipeline processing source extraction flag is a placeholder only, and is always set to zero in all passbands in the merged source lists. If you need to know when a particular image detection is a component of a deblend or not, test bit 4 of attribute ppErrBits (see corresponding glossary entry) which is set by WFAU's postprocessing software based on testing the areal profiles aprof28 (these are set by CASU to 1 for deblended components, or positive values for nondeblended detections). We encode this in an information bit of ppErrBits for convenience when querying the merged source tables. 
nbhdStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c3 from FerreiraLopes & Cross 2017, Eq. 18, in fit to astrometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhdStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Parameter, c0 from FerreiraLopes & Cross 2017, Eq. 18, in fit to photometric rms vs magnitude in Nbh band. 
real 
4 

0.9999995e9 
stat.fit.param 
The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhEll 
[nspid]Source 
WSA NonSurvey 
1b/a, where a/b=semimajor/minor axes in Nbh 
real 
4 

0.9999995e9 
PHYS_ELLIPTICITY 
nbheNum 
[nspid]MergeLog 
WSA NonSurvey 
the extension number of this Nbh frame 
tinyint 
1 


NUMBER 
nbhErrBits 
[nspid]Source 
WSA NonSurvey 
processing warning/error bitwise flags in Nbh 
int 
4 

99999999 
CODE_MISC 
Apparently not actually an error bit flag, but a count of the number of zero confidence pixels in the default (2 arcsec diameter) aperture. 
nbhEta 
[nspid]Source 
WSA NonSurvey 
Offset of Nbh detection from master position (+north/south) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_DEC_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
nbhexpML 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Expected magnitude limit of frameSet in this in Nbh band. 
real 
4 

0.9999995e9 

The expected magnitude limit of an intermediate stack, based on the total exposure time. expML=Filter.oneSecML+1.25*log10(totalExpTime). Since different intermediate stacks can have different exposure times, the totalExpTime is the minimum, as long as the number of stacks with this minimum make up 10% of the total. This is a more conservative treatment than just taking the mean or median total exposure time. 
nbhExpRms 
[nspid]Variability 
WSA NonSurvey 
Rms calculated from polynomial fit to modal RMS as a function of magnitude in Nbh band 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhGausig 
[nspid]Source 
WSA NonSurvey 
RMS of axes of ellipse fit in Nbh 
real 
4 
pixels 
0.9999995e9 
MORPH_PARAM 
nbhHallMag 
[nspid]Source 
WSA NonSurvey 
Total point source Nbh mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhHallMagErr 
[nspid]Source 
WSA NonSurvey 
Error in total point source Nbh mag 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhIntRms 
[nspid]Variability 
WSA NonSurvey 
Intrinsic rms in Nbhband 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhisDefAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Use a default model for the astrometric noise in Nbh band. 
tinyint 
1 

0 
meta.code 
nbhisDefPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Use a default model for the photometric noise in Nbh band. 
tinyint 
1 

0 

nbhMagMAD 
[nspid]Variability 
WSA NonSurvey 
Median Absolute Deviation of Nbh magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhMagRms 
[nspid]Variability 
WSA NonSurvey 
rms of Nbh magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhmaxCadence 
[nspid]Variability 
WSA NonSurvey 
maximum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhMaxMag 
[nspid]Variability 
WSA NonSurvey 
Maximum magnitude in Nbh band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhmeanMag 
[nspid]Variability 
WSA NonSurvey 
Mean Nbh magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhmedCadence 
[nspid]Variability 
WSA NonSurvey 
median gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhmedianMag 
[nspid]Variability 
WSA NonSurvey 
Median Nbh magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhmfID 
[nspid]MergeLog 
WSA NonSurvey 
the UID of the relevant Nbh multiframe 
bigint 
8 


ID_FRAME 
nbhminCadence 
[nspid]Variability 
WSA NonSurvey 
minimum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhMinMag 
[nspid]Variability 
WSA NonSurvey 
Minimum magnitude in Nbh band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhndof 
[nspid]Variability 
WSA NonSurvey 
Number of degrees of freedom for chisquare 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhnDofAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Number of degrees of freedom of astrometric fit in Nbh band. 
smallint 
2 

9999 
stat.fit.dof;stat.param 
The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbhnDofPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Number of degrees of freedom of photometric fit in Nbh band. 
smallint 
2 

9999 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbhnFlaggedObs 
[nspid]Variability 
WSA NonSurvey 
Number of detections in Nbh band flagged as potentially spurious by u10b11Detection.ppErrBits 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhnFlaggedObs 
[nspid]Variability 
WSA NonSurvey 
Number of detections in Nbh band flagged as potentially spurious by u12ak3Detection.ppErrBits 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhnGoodObs 
[nspid]Variability 
WSA NonSurvey 
Number of good detections in Nbh band 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhNgt3sig 
[nspid]Variability 
WSA NonSurvey 
Number of good detections in Nbhband that are more than 3 sigma deviations (nbhAperMagN < (nbhMeanMag3*nbhMagRms) 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhnMissingObs 
[nspid]Variability 
WSA NonSurvey 
Number of Nbh band frames that this object should have been detected on and was not 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhPA 
[nspid]Source 
WSA NonSurvey 
ellipse fit celestial orientation in Nbh 
real 
4 
Degrees 
0.9999995e9 
POS_POSANG 
nbhPetroMag 
[nspid]Source 
WSA NonSurvey 
Extended source Nbh mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhPetroMagErr 
[nspid]Source 
WSA NonSurvey 
Error in extended source Nbh mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhppErrBits 
[nspid]Source 
WSA NonSurvey 
additional WFAU postprocessing error bits in Nbh 
int 
4 

0 
CODE_MISC 
Postprocessing error quality bit flags assigned (NB: from UKIDSS DR2 release onwards) in the WSA curation procedure for survey data. From least to most significant byte in the 4byte integer attribute byte 0 (bits 0 to 7) corresponds to information on generally innocuous conditions that are nonetheless potentially significant as regards the integrity of that detection; byte 1 (bits 8 to 15) corresponds to warnings; byte 2 (bits 16 to 23) corresponds to important warnings; and finally byte 3 (bits 24 to 31) corresponds to severe warnings: Byte  Bit  Detection quality issue  Threshold or bit mask  Applies to     Decimal  Hexadecimal   0  4  Deblended  16  0x00000010  All VDFS catalogues  0  6  Bad pixel(s) in default aperture  64  0x00000040  All VDFS catalogues  1  15  Source in poor flat field region  32768  0x00008000  All but mosaics  2  16  Close to saturated  65536  0x00010000  All VDFS catalogues (though deeps excluded prior to DR8)  2  17  Photometric calibration probably subject to systematic error  131072  0x00020000  GPS only  2  19  Possible crosstalk artefact/contamination  524288  0x00080000  All but GPS  2  22  Lies within a dither offset of the stacked frame boundary  4194304  0x00400000  All but mosaics  In this way, the higher the error quality bit flag value, the more likely it is that the detection is spurious. The decimal threshold (column 4) gives the minimum value of the quality flag for a detection having the given condition (since other bits in the flag may be set also; the corresponding hexadecimal value, where each digit corresponds to 4 bits in the flag, can be easier to compute when writing SQL queries to test for a given condition). For example, to exclude all K band sources in the LAS having any error quality condition other than informational ones, include a predicate ... AND kppErrBits ≤ 255. See the SQL Cookbook and other online pages for further information. 
nbhprobVar 
[nspid]Variability 
WSA NonSurvey 
Probability of variable from chisquare (and other data) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhPsfMag 
[nspid]Source 
WSA NonSurvey 
Point source profilefitted Nbh mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhPsfMagErr 
[nspid]Source 
WSA NonSurvey 
Error in point source profilefitted Nbh mag 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhSeqNum 
[nspid]Source 
WSA NonSurvey 
the running number of the Nbh detection 
int 
4 

99999999 
ID_NUMBER 
nbhSerMag2D 
[nspid]Source 
WSA NonSurvey 
Extended source Nbh mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbhSerMag2DErr 
[nspid]Source 
WSA NonSurvey 
Error in extended source Nbh mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbhskewness 
[nspid]Variability 
WSA NonSurvey 
Skewness in Nbh band (see Sesar et al. 2007) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhtotalPeriod 
[nspid]Variability 
WSA NonSurvey 
total period of observations (last obsfirst obs) 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbhVarClass 
[nspid]Variability 
WSA NonSurvey 
Classification of variability in this band 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbhXi 
[nspid]Source 
WSA NonSurvey 
Offset of Nbh detection from master position (+east/west) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_RA_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
nbjAperMag1 
[nspid]SynopticSource 
WSA NonSurvey 
Extended source Nbj aperture corrected mag (0.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag1Err 
[nspid]SynopticSource 
WSA NonSurvey 
Error in extended source Nbj mag (0.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjAperMag2 
[nspid]SynopticSource 
WSA NonSurvey 
Extended source Nbj aperture corrected mag (1.4 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag2Err 
[nspid]SynopticSource 
WSA NonSurvey 
Error in extended source Nbj mag (1.4 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjAperMag3 
[nspid]Source 
WSA NonSurvey 
Default point/extended source Nbj aperture corrected mag (2.0 arcsec aperture diameter) If in doubt use this flux estimator 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag3 
[nspid]SynopticSource 
WSA NonSurvey 
Default point/extended source Nbj aperture corrected mag (2.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag3Err 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Error in default point/extended source Nbj mag (2.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjAperMag4 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Extended source Nbj aperture corrected mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag4Err 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Error in extended source Nbj mag (2.8 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjAperMag5 
[nspid]SynopticSource 
WSA NonSurvey 
Extended source Nbj aperture corrected mag (4.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag5Err 
[nspid]SynopticSource 
WSA NonSurvey 
Error in extended source Nbj mag (4.0 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjAperMag6 
[nspid]Source 
WSA NonSurvey 
Extended source Nbj aperture corrected mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjAperMag6Err 
[nspid]Source 
WSA NonSurvey 
Error in extended source Nbj mag (5.7 arcsec aperture diameter) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjaStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, a, in fit to astrometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbjaStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, a, in fit to photometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbjbestAper 
[nspid]Variability 
WSA NonSurvey 
Best aperture (16) for photometric statistics in the Nbj band 
int 
4 

9999 

Aperture magnitude (16) which gives the lowest RMS for the object. All apertures have the appropriate aperture correction. This can give better values in crowded regions than aperMag3 (see Irwin et al. 2007, MNRAS, 375, 1449) 
nbjbStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, b, in fit to astrometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbjbStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, b, in fit to photometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbjchiSqAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Goodness of fit of Strateva function to astrometric data in Nbj band 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbjchiSqpd 
[nspid]Variability 
WSA NonSurvey 
Chi square (per degree of freedom) fit to data (mean and expected rms) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjchiSqPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Goodness of fit of Strateva function to photometric data in Nbj band 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbjClass 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
discrete image classification flag in Nbj 
smallint 
2 

9999 
CLASS_MISC 
nbjClassStat 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
N(0,1) stellarnessofprofile statistic in Nbj 
real 
4 

0.9999995e9 
STAT_PROP 
nbjcStratAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, c, in fit to astrometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbjcStratPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Strateva parameter, c, in fit to photometric rms vs magnitude in Nbj band, see Sesar et al. 2007. 
real 
4 

0.9999995e9 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbjDeblend 
[nspid]Source 
WSA NonSurvey 
placeholder flag indicating parent/child relation in Nbj 
int 
4 

99999999 
CODE_MISC 
This CASU pipeline processing source extraction flag is a placeholder only, and is always set to zero in all passbands in the merged source lists. If you need to know when a particular image detection is a component of a deblend or not, test bit 4 of attribute ppErrBits (see corresponding glossary entry) which is set by WFAU's postprocessing software based on testing the areal profiles aprof28 (these are set by CASU to 1 for deblended components, or positive values for nondeblended detections). We encode this in an information bit of ppErrBits for convenience when querying the merged source tables. 
nbjDeblend 
[nspid]SynopticSource 
WSA NonSurvey 
placeholder flag indicating parent/child relation in Nbj 
int 
4 

99999999 
CODE_MISC 
nbjEll 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
1b/a, where a/b=semimajor/minor axes in Nbj 
real 
4 

0.9999995e9 
PHYS_ELLIPTICITY 
nbjeNum 
[nspid]MergeLog, [nspid]SynopticMergeLog 
WSA NonSurvey 
the extension number of this Nbj frame 
tinyint 
1 


NUMBER 
nbjErrBits 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
processing warning/error bitwise flags in Nbj 
int 
4 

99999999 
CODE_MISC 
Apparently not actually an error bit flag, but a count of the number of zero confidence pixels in the default (2 arcsec diameter) aperture. 
nbjEta 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Offset of Nbj detection from master position (+north/south) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_DEC_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
nbjexpML 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Expected magnitude limit of frameSet in this in Nbj band. 
real 
4 

0.9999995e9 

The expected magnitude limit of an intermediate stack, based on the total exposure time. expML=Filter.oneSecML+1.25*log10(totalExpTime). Since different intermediate stacks can have different exposure times, the totalExpTime is the minimum, as long as the number of stacks with this minimum make up 10% of the total. This is a more conservative treatment than just taking the mean or median total exposure time. 
nbjExpRms 
[nspid]Variability 
WSA NonSurvey 
Rms calculated from polynomial fit to modal RMS as a function of magnitude in Nbj band 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjGausig 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
RMS of axes of ellipse fit in Nbj 
real 
4 
pixels 
0.9999995e9 
MORPH_PARAM 
nbjHallMag 
[nspid]Source 
WSA NonSurvey 
Total point source Nbj mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjHallMagErr 
[nspid]Source 
WSA NonSurvey 
Error in total point source Nbj mag 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjIntRms 
[nspid]Variability 
WSA NonSurvey 
Intrinsic rms in Nbjband 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjisDefAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Use a default model for the astrometric noise in Nbj band. 
tinyint 
1 

0 

nbjisDefPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Use a default model for the photometric noise in Nbj band. 
tinyint 
1 

0 

nbjMagMAD 
[nspid]Variability 
WSA NonSurvey 
Median Absolute Deviation of Nbj magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjMagRms 
[nspid]Variability 
WSA NonSurvey 
rms of Nbj magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjmaxCadence 
[nspid]Variability 
WSA NonSurvey 
maximum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjMaxMag 
[nspid]Variability 
WSA NonSurvey 
Maximum magnitude in Nbj band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjmeanMag 
[nspid]Variability 
WSA NonSurvey 
Mean Nbj magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjmedCadence 
[nspid]Variability 
WSA NonSurvey 
median gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjmedianMag 
[nspid]Variability 
WSA NonSurvey 
Median Nbj magnitude 
real 
4 
mag 
0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjmfID 
[nspid]MergeLog, [nspid]SynopticMergeLog 
WSA NonSurvey 
the UID of the relevant Nbj multiframe 
bigint 
8 


ID_FRAME 
nbjminCadence 
[nspid]Variability 
WSA NonSurvey 
minimum gap between observations 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjMinMag 
[nspid]Variability 
WSA NonSurvey 
Minimum magnitude in Nbj band, of good detections 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjmjExt 
[nspid]Source 
WSA NonSurvey 
Extended source colour NbjJ (using aperMag3) 
real 
4 
mag 
0.9999995e9 
PHOT_COLOR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
nbjmjExtErr 
[nspid]Source 
WSA NonSurvey 
Error on extended source colour NbjJ 
real 
4 
mag 
0.9999995e9 
ERROR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
nbjmjPnt 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Point source colour NbjJ (using aperMag3) 
real 
4 
mag 
0.9999995e9 
PHOT_COLOR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
nbjmjPntErr 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Error on point source colour NbjJ 
real 
4 
mag 
0.9999995e9 
ERROR 
Default colours from pairs of adjacent passbands within a given set (e.g. YJ, JH and HK for YJHK) are recorded in the merged source table for ease of querying and speedy querying via indexing of these attributes. Presently, the pointsource colours and extended source colours are computed from the aperture corrected AperMag3 fixed 2 arcsec aperture diameter measures (for consistent measurement across all passbands) and generally good signaltonoise. At some point in the future, this may be changed such that pointsource colours will be computed from the PSFfitted measures and extended source colours computed from the 2d Sersic model profile fits. 
nbjndof 
[nspid]Variability 
WSA NonSurvey 
Number of degrees of freedom for chisquare 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjnDofAst 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Number of degrees of freedom of astrometric fit in Nbj band. 
smallint 
2 

9999 

The best fit solution to the expected RMS position around the mean for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. 
nbjnDofPht 
[nspid]VarFrameSetInfo 
WSA NonSurvey 
Number of degrees of freedom of photometric fit in Nbj band. 
smallint 
2 

9999 

The best fit solution to the expected RMS brightness (in magnitudes) for all objects in the frameset. Objects were binned in ranges of magnitude and the median RMS (after clipping out variable objects using the medianabsolute deviation) was calculated. The Strateva function $\zeta(m)>=a+b\,10^{0.4m}+c\,10^{0.8m}$ was fit, where $\zeta(m)$ is the expected RMS as a function of magnitude. The chisquared and number of degrees of freedom are also calculated. This technique was used in Sesar et al. 2007, AJ, 134, 2236. 
nbjnFlaggedObs 
[nspid]Variability 
WSA NonSurvey 
Number of detections in Nbj band flagged as potentially spurious by calDetection.ppErrBits 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjnGoodObs 
[nspid]Variability 
WSA NonSurvey 
Number of good detections in Nbj band 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjNgt3sig 
[nspid]Variability 
WSA NonSurvey 
Number of good detections in Nbjband that are more than 3 sigma deviations 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjnMissingObs 
[nspid]Variability 
WSA NonSurvey 
Number of Nbj band frames that this object should have been detected on and was not 
int 
4 

0 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjPA 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
ellipse fit celestial orientation in Nbj 
real 
4 
Degrees 
0.9999995e9 
POS_POSANG 
nbjPetroMag 
[nspid]Source 
WSA NonSurvey 
Extended source Nbj mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjPetroMagErr 
[nspid]Source 
WSA NonSurvey 
Error in extended source Nbj mag (Petrosian) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjppErrBits 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
additional WFAU postprocessing error bits in Nbj 
int 
4 

0 
CODE_MISC 
Postprocessing error quality bit flags assigned (NB: from UKIDSS DR2 release onwards) in the WSA curation procedure for survey data. From least to most significant byte in the 4byte integer attribute byte 0 (bits 0 to 7) corresponds to information on generally innocuous conditions that are nonetheless potentially significant as regards the integrity of that detection; byte 1 (bits 8 to 15) corresponds to warnings; byte 2 (bits 16 to 23) corresponds to important warnings; and finally byte 3 (bits 24 to 31) corresponds to severe warnings: Byte  Bit  Detection quality issue  Threshold or bit mask  Applies to     Decimal  Hexadecimal   0  4  Deblended  16  0x00000010  All VDFS catalogues  0  6  Bad pixel(s) in default aperture  64  0x00000040  All VDFS catalogues  1  15  Source in poor flat field region  32768  0x00008000  All but mosaics  2  16  Close to saturated  65536  0x00010000  All VDFS catalogues (though deeps excluded prior to DR8)  2  17  Photometric calibration probably subject to systematic error  131072  0x00020000  GPS only  2  19  Possible crosstalk artefact/contamination  524288  0x00080000  All but GPS  2  22  Lies within a dither offset of the stacked frame boundary  4194304  0x00400000  All but mosaics  In this way, the higher the error quality bit flag value, the more likely it is that the detection is spurious. The decimal threshold (column 4) gives the minimum value of the quality flag for a detection having the given condition (since other bits in the flag may be set also; the corresponding hexadecimal value, where each digit corresponds to 4 bits in the flag, can be easier to compute when writing SQL queries to test for a given condition). For example, to exclude all K band sources in the LAS having any error quality condition other than informational ones, include a predicate ... AND kppErrBits ≤ 255. See the SQL Cookbook and other online pages for further information. 
nbjprobVar 
[nspid]Variability 
WSA NonSurvey 
Probability of variable from chisquare (and other data) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjPsfMag 
[nspid]Source 
WSA NonSurvey 
Point source profilefitted Nbj mag 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjPsfMagErr 
[nspid]Source 
WSA NonSurvey 
Error in point source profilefitted Nbj mag 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjSeqNum 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
the running number of the Nbj detection 
int 
4 

99999999 
ID_NUMBER 
nbjSerMag2D 
[nspid]Source 
WSA NonSurvey 
Extended source Nbj mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
PHOT_MAG 
nbjSerMag2DErr 
[nspid]Source 
WSA NonSurvey 
Error in extended source Nbj mag (profilefitted) 
real 
4 
mag 
0.9999995e9 
ERROR 
nbjskewness 
[nspid]Variability 
WSA NonSurvey 
Skewness in Nbj band (see Sesar et al. 2007) 
real 
4 

0.9999995e9 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjtotalPeriod 
[nspid]Variability 
WSA NonSurvey 
total period of observations (last obsfirst obs) 
real 
4 
days 
0.9999995e9 

The observations are classified as good, flagged or missing. Flagged observations are ones where the object has a ppErrBit flag. Missing observations are observations of the part of the sky that include the position of the object, but had no detection. All the statistics are calculated from good observations. The cadence parameters give the minimum, median and maximum time between observations, which is useful to know if the data could be used to find a particular type of variable. 
nbjVarClass 
[nspid]Variability 
WSA NonSurvey 
Classification of variability in this band 
smallint 
2 

9999 

The photometry is calculated for good observations in the best aperture. The mean, rms, median, median absolute deviation, minMag and maxMag are quite standard. The skewness is calculated as in Sesar et al. 2007, AJ, 134, 2236. The number of good detections that are more than 3 standard deviations can indicate a distribution with many outliers. In each frameset, the mean and rms are used to derive a fit to the expected rms as a function of magnitude. The parameters for the fit are stored in VarFrameSetInfo and the value for the source is in expRms. This is subtracted from the rms in quadrature to get the intrinsic rms: the variability of the object beyond the noise in the system. The chisquared is calculated, assuming a nonvariable object which has the noise from the expectedrms and mean calculated as above. The probVar statistic assumes a chisquared distribution with the correct number of degrees of freedom. The varClass statistic is 1, if the probVar>0.9 and intrinsicRMS/expectedRMS>3. 
nbjXi 
[nspid]Source, [nspid]SynopticSource 
WSA NonSurvey 
Offset of Nbj detection from master position (+east/west) 
real 
4 
arcsec 
0.9999995e9 
POS_EQ_RA_OFF 
When associating individual passband detections into merged sources, a generous (in terms of the positional uncertainties) pairing radius of 2.0 (UKIDSS LAS and GPS; UHS; also nonsurvey programmes) or 1.0 (UKIDSS GPS, DXS and UDS) arcseconds is used, the higher value enabling pairing of moving sources when epoch separations may be several years. Such a large association criterion can of course lead to spurious pairings in the merged sources lists (although note that between passband pairs, handshake pairing is done: both passbands must agree that the candidate pair is their nearest neighbour for the pair to propagate through into the merged source table). In order to help filter spurious pairings out, and assuming that large positional offsets between the different passband detections are not expected (e.g. because of source motion, or larger than usual positional uncertainties) then the attributes Xi and Eta can be used to filter any pairings with suspiciously large offsets in one or more bands. For example, for a clean sample of QSOs from the LAS, you might wish to insist that the offsets in the selected sample are all below 1 arcsecond: simply add WHERE clauses into the SQL sample selection script to exclude all Xi and Eta values larger than the threshold you want. NB: the master position is the position of the detection in the shortest passband in the set, rather than the ra/dec of the source as stored in source attributes of the same name. The former is used in the pairing process, while the latter is generally the optimally weighted mean position from an astrometric solution or other combinatorial process of all individual detection positions across the available passbands. 
nDof 
[nspid]SatelliteOrbits 
WSA NonSurvey 
Number of degrees of freedom of fit 
int 
4 



neighboursSchema 
[nspid]Programme 
WSA NonSurvey 
Script file that describes the neighbour tables schema for this programme 
varchar 
64 


?? 
neighbourTable 
[nspid]RequiredNeighbours 
WSA NonSurvey 
the name of the neighbour join table 
varchar 
256 


ID_TABLE 
newBrframe 
[nspid]MergeLog, [nspid]SynopticMergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newFeiiframe 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newFrameSet 
[nspid]JHKmergeLog, [nspid]JKmergeLog, [nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]YJHKmergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
Flag used internally by curation applications 
tinyint 
1 


CODE_MISC 
newH2_1frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newH2_2frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newH2frame 
[nspid]JHKmergeLog, [nspid]MergeLog, [nspid]SynopticMergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newHframe 
[nspid]JHKmergeLog, [nspid]JKmergeLog, [nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]YJHKmergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newJ_1frame 
[nspid]MergeLog, [nspid]YJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newJ_2frame 
[nspid]MergeLog, [nspid]YJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newJ_3frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newJ_4frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newJframe 
[nspid]JHKmergeLog, [nspid]JKmergeLog, [nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newK_1frame 
[nspid]JHKmergeLog, [nspid]MergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newK_2frame 
[nspid]JHKmergeLog, [nspid]MergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newKframe 
[nspid]JKmergeLog, [nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]YJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newlyIngested 
[nspid]Multiframe 
WSA NonSurvey 
Curation flag for internal use only (0=no, 1=yes) 
tinyint 
1 

1 
?? 
newNbhframe 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newNbjframe 
[nspid]MergeLog, [nspid]SynopticMergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newY_1frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newY_2frame 
[nspid]MergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newYframe 
[nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]YJHKmergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
newZframe 
[nspid]MergeLog, [nspid]SynopticMergeLog, [nspid]ZYJHKmergeLog 
WSA NonSurvey 
new/old flag (1/0) of this detector image 
tinyint 
1 


CODE_MISC 
nFoc 
[nspid]Multiframe 
WSA NonSurvey 
Number of positions in focus scan {image primary HDU keyword: NFOC} 
smallint 
2 

9999 
meta.number 
nFocScan 
[nspid]Multiframe 
WSA NonSurvey 
Number of focus scans in focus test {image primary HDU keyword: NFOCSCAN} 
smallint 
2 

9999 
meta.number 
nFrames 
[nspid]ExtendedSource, [nspid]GcsPointSource, [nspid]GpsPointSource, [nspid]JHKsource, [nspid]LasPointSource, [nspid]PointSource, [nspid]Source, [nspid]YJHKsource, [nspid]ZYJHKsource 
WSA NonSurvey 
No. of frames used for this proper motion measurement 
tinyint 
1 

0 
NUMBER 
nFrames 
[nspid]Variability 
WSA NonSurvey 
Number of frames with good detections used to calculate astrometric fits 
int 
4 

0 
NUMBER 
The Variability table contains statistics from the set of observations of each source. At present, the mean ra and dec and the error in two tangential directions are calculated. The "ra" direction is defined as tangential to both the radial direction and the cartesian zaxis and the "dec" direction is defined as both the radial direction and the "ra" direction. Since the current model is just the mean and standard deviation of the data, then the chisquared of the fit=1. Data from good frames across all bands go into the astrometric model determination. This will include bands in nonsynoptic filters: the one observation in these bands can help. In future releases a fit will be made to the rms data as a function of magnitude in each band, as has already happened for photometric data and a motion model that incorporates proper motion (and possibly parallax) will be used. The motion model is a parameter in the VarFrameSetInfo table. 
nightZPCat 
[nspid]MultiframeDetector 
WSA NonSurvey 
Average photometric zero point for night {catalogue extension keyword: NIGHTZPT} 
real 
4 
mags 
0.9999995e9 
?? 
nightZPCat 
[nspid]PreviousMFDZP 
WSA NonSurvey 
Average photometric zero point for night 
real 
4 
mags 
0.9999995e9 
?? 
nightZPErrCat 
[nspid]MultiframeDetector 
WSA NonSurvey 
Photometric zero point sigma for night {catalogue extension keyword: NIGHTZRR} <0.05 mags for a good night 
real 
4 
mags 
0.9999995e9 
?? 
nightZPErrCat 
[nspid]PreviousMFDZP 
WSA NonSurvey 
Photometric zero point sigma for night <0.05 mags for a good night 
real 
4 
mags 
0.9999995e9 
?? 
nightZPNum 
[nspid]MultiframeDetector 
WSA NonSurvey 
Number of ZP in band used to calculate nightZPCat {catalogue extension keyword: NIGHTNUM} 
int 
4 
mags 
99999999 
?? 
nightZPNum 
[nspid]PreviousMFDZP 
WSA NonSurvey 
Number of ZP in band used to calculate nightZPCat 
int 
4 
mags 
99999999 
?? 
njitter 
[nspid]Multiframe 
WSA NonSurvey 
Number of positions in telescope pattern {image primary HDU keyword: NJITTER} 
smallint 
2 

9999 
meta.number 
nonperp 
[nspid]AstrometricInfo 
WSA NonSurvey 
Nonperpendicularity of axes 
float 
8 
degrees 
0.9999995e9 
?? 
nonperp 
[nspid]AstrometricInfo 
WSA NonSurvey 
Nonperpendicularity of axes 
float 
8 
radians 
0.9999995e9 
?? 
nPass 
[nspid]RequiredFilters 
WSA NonSurvey 
the number of passes that will be made 
smallint 
2 


NUMBER 
nPix 
[nspid]SatelliteDetection 
WSA NonSurvey 
No. of pixels above threshold 
int 
4 
pixels 

NUMBER 
nTrails 
[nspid]SatelliteOrbits 
WSA NonSurvey 
Number of satellite trails used to compute the orbit 
int 
4 



numAxes 
[nspid]MultiframeDetector 
WSA NonSurvey 
Number of data axes; eg. 2 
tinyint 
1 


meta.number 
numberStk 
[nspid]RequiredStack 
WSA NonSurvey 
Number of intermediate stacks. If default, stack all good quality stacks 
int 
4 

99999999 

numDetectors 
[nspid]Multiframe 
WSA NonSurvey 
The number of "detectors" (=image extensions in FITS file) 
tinyint 
1 


?? 
numExp 
[nspid]Multiframe 
WSA NonSurvey 
Number of exposures in integration {image primary HDU keyword: NEXP} 
smallint 
2 

9999 
meta.number 
numInts 
[nspid]Multiframe 
WSA NonSurvey 
Number of integrations in observation {image primary HDU keyword: NINT} 
smallint 
2 


meta.number 
numReads 
[nspid]Multiframe 
WSA NonSurvey 
Number of reads per exposure {image primary HDU keyword: NREADS} 
smallint 
2 

9999 
meta.number 
numRms 
[nspid]CurrentAstrometry, [nspid]PreviousAstrometry 
WSA NonSurvey 
No. of astrometric standards used in fit {image extension keyword: NUMBRMS} 
int 
4 

99999999 
stat.fit.param 
numZPCat 
[nspid]MultiframeDetector 
WSA NonSurvey 
Number of standards used in determining photZPCat and photZPCatErr {catalogue extension keyword: NUMZPT} 
int 
4 

99999999 

numZPCat 
[nspid]PreviousMFDZP 
WSA NonSurvey 
Number of standards used in determining photZP and photZPErr 
int 
4 

99999999 

nuStep 
[nspid]Multiframe 
WSA NonSurvey 
Number of positions in microstep pattern {image primary HDU keyword: NUSTEP} 
smallint 
2 

9999 
meta.number 
nustep 
[nspid]RequiredMosaic, [nspid]RequiredStack 
WSA NonSurvey 
Amount of microstepping 
tinyint 
1 


?? 