| E | 
|---|
| Name | Schema Table | Database | Description | Type | Length | Unit | Default Value | Unified Content Descriptor | 
|---|
 | ell | [nspid]Detection | WSA NonSurvey | 1-b/a, where a/b=semi-major/minor axes {catalogue TType keyword: Ellipticity} ellipticity = 1.0-σ_a/σ_b
 | real | 4 |  |  | PHYS_ELLIPTICITY | 
 | ell | [nspid]Detection | WSA NonSurvey | 1-b/a, where a/b=semi-major/minor axes {catalogue TType keyword: Ellipticity} | real | 4 |  |  | PHYS_ELLIPTICITY | 
 | endCol | [nspid]MultiframeDetector | WSA NonSurvey | End column of array readout {image extension keyword: RDOUT_X2} | smallint | 2 |  |  | NUMBER | 
 | endDate | [nspid]AstrCalVers, [nspid]PreviousSpatialMap, [nspid]PreviousStdStarInfo | WSA NonSurvey | MJD of the end time for this version of the calibration | float | 8 | Julian days |  | TIME_DATE | 
 | endDate | [nspid]PhotCalVers | WSA NonSurvey | Date time of end time for this version of the calibration (MM-DD-YYYY) | datetime | 8 | MM-DD-YYYY | 12-31-9999 | TIME_DATE | 
 | endRow | [nspid]MultiframeDetector | WSA NonSurvey | End row of array readout {image extension keyword: RDOUT_Y2} | smallint | 2 |  |  | NUMBER | 
 | epoch | [nspid]FSstars | WSA NonSurvey | The epoch of columns ra and dec | real | 4 | years | -0.9999995e9 |  | 
 | epoch | [nspid]Source | WSA NonSurvey | Epoch of position measurement | float | 8 | Years | -0.9999995e9 | TIME_EPOCH | 
 | equinox | [nspid]Multiframe | WSA NonSurvey | Equinox of object position {image primary HDU keyword: EQUINOX} | real | 4 | years | -0.9999995e9 | TIME_EQUINOX | 
 | errBits | [nspid]Detection | WSA NonSurvey | processing warning/error bitwise flags {catalogue TType keyword: Error_bit_flag} | int | 4 |  |  | CODE_MISC | 
 | eta | [nspid]CurrentAstrometry, [nspid]PreviousAstrometry | WSA NonSurvey | SDSS system spherical co-ordinate 2 of device centre | float | 8 | Degrees |  | POS | 
 | eta | [nspid]Detection, [nspid]Source | WSA NonSurvey | SDSS system spherical co-ordinate 2 | float | 8 | Degrees |  | POS | 
 | expTime | [nspid]Multiframe | WSA NonSurvey | Integration time per exposure {image primary HDU keyword: EXP_TIME} | real | 4 | seconds | -0.9999995e9 | TIME_EXPTIME | 
 | extinction | [nspid]Multiframe | WSA NonSurvey | Extinction coefficient {image primary HDU keyword: EXTINCT} | real | 4 | mag | -0.9999995e9 |  | 
 | extinctionCat | [nspid]MultiframeDetector | WSA NonSurvey | Extinction coefficient for the catalogue data {catalogue extension keyword:  EXTINCT} | real | 4 | mags | -0.9999995e9 | ?? | 
| For WFCAM these are currently set to a constant clear night level, which within the current measuring error is the same for all passbands.  Note that the frame-by-frame derived ZP from 2MASS automatically corrects for extinction variations, assuming they are uniform across the field of view. | 
 | extinctionExt | [nspid]MultiframeDetector | WSA NonSurvey | Extinction coefficient of the detector {image extension keyword: EXTINCT} | real | 4 | mags | -0.9999995e9 | ?? | 
| For WFCAM these are currently set to a constant clear night level, which within the current measuring error is the same for all passbands.  Note that the frame-by-frame derived ZP from 2MASS automatically corrects for extinction variations, assuming they are uniform across the field of view. | 
 | extNum | [nspid]CurrentAstrometry, [nspid]Detection, [nspid]MultiframeDetector, [nspid]PreviousAstrometry, [nspid]PreviousMFDZP | WSA NonSurvey | the extension number of this frame | tinyint | 1 |  |  | NUMBER | 
 | extractTool | [nspid]RequiredMosaic, [nspid]RequiredStack | WSA NonSurvey | Name of extraction tool to be used | varchar | 8 |  | 'CASU' | ?? | 
 | extTableID | [nspid]ExternalSurveyTable, [nspid]RequiredNeighbours | WSA NonSurvey | the unique table ID | int | 4 |  |  | ID_MAIN | 
 | extTableName | [nspid]ExternalSurveyTable | WSA NonSurvey | the name of the table | varchar | 256 |  |  | ID_TABLE |