Vis Master Flat Frame Product¶
Data product name¶
DpdVisMasterFlatFrame
Data product custodian¶
Name of the Schema file¶
euc-vis-MasterFlatFrame.xsdData product elements¶
- Header:
object of type sys:genericHeader
- Data:
object of type vis:visMasterFlatFrame
- QualityFlags:
object of type dqc:sqfPlaceHolder
- Parameters:
object of type ppr:genericKeyValueParameters
Schema documentation tag¶
Documentation for data product element DpdVisMasterFlatFrame:
Master Flat Calibration Pipeline result, using a series of flat calibration exposures to calculate a MasterFlat to be used in other ou-vis pipelines.
Documentation for data product element Header:
The generic header of the product.
Processing Element(s) creating/using the data product¶
Final data product of the Master Flat Calibraiton pipeline
Processing function using the data product¶
VIS – Used by PRNU Correction tasks in several pipelines: (ProcessField, LargeFlat, BrighterFatter)
Detailed description of the data product¶
Master Flat Calibration Pipeline result, using a series of flat calibration exposures to calculate a MasterFlat to be used in other ou-vis pipelines.
The product produces a Flagmap fits file same size as the Master PRNU whereby each pixel is a standard bit. The Master PRNU will set the bits for flagging hot and cold pixels. The Flagmap data format is defined in the data model here and is described in human-readable format here.
The product produces a LED Profile fits file same size as the Master PRNU, which quantifies the Illumination of the quadrant by the calibration unit LED.
Each pixel in a CCD has slightly different levels of response to light, due to manufacturing irregularities. The PRNU of a pixel is defined here as the level of responsiveness relative to its nearby neighbours, where the average is 1.0. The nearest neighbours have the highest weighting in this average. This weighting is implicit in the use of surface fitting to remove larger scale variations. Those variations include sky background, calibration LED illumination and shutter effects.
The PRNU model is stored as a 2-D image, not including prescan or overscan areas. PRNU is calibrated using a set of PRNU exposures, illuminated by an LED in the Calibration Unit which sits in front of the focal plane. FLat exposures have different fluence levels and used for different purposes in other pipelines.
When PRNU product is used during Correction, is a multiplicative effect, so the application of a correction involves simply dividing an image by the PRNU model.
The final product will be 144 extensions based on the quadrants with the EXTNAME noted as the CCDID, 2048x2066 pixels in ADU units.
Detailed Algorithm information can be viewed from tech note: https://euclid.roe.ac.uk/dmsf/files/16476/view
Primary Header:
SIMPLE |
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BITPIX |
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NAXIS |
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EXTEND |
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OBSTYPE |
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ToFill |
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N_CCD |
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ToFill |
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EXPTIME |
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Commanded integration time in seconds, e.g. 565.0 |
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DATAUNIT |
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ToFill |
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RA |
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Commanded FPA pointing right ascension (deg) |
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DEC |
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Commanded FPA pointing declination (deg) |
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INSTRUME |
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VIS instrument |
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SEQID |
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VIS sequences as defined in EUCL-IFS-ICD-6-002 VIS Data ICD |
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ORIENTAT |
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ToFill |
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DATE |
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UT date when this file was created |
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DATE-OBS |
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UTC Date of observation (start), e.g. ‘2014-03-15T09:30:09.313’ |
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VERSION |
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END |
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Extension Header:
XTENSION |
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BITPIX |
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NAXIS |
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NAXIS1 |
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NAXIS2 |
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PCOUNT |
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GCOUNT |
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TIMESYS |
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Time scale of the time-related keywords |
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DATE |
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UT date when this file was created |
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MJDATE |
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MJD start time, e.g. 56731.39594113 |
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WCSAXES |
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Number of coordinate axes |
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CRPIX1 |
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Reference pixel x coordinate |
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CRPIX2 |
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Reference pixel y coordinate |
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CRVAL1 |
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Right ascension at ref pixel |
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CRVAL2 |
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Declination at ref pixel |
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CTYPE1 |
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Coordinamte 1 type |
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CTYPE2 |
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Coordinamte 2 type |
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RA |
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Commanded FPA pointing right ascension (deg) |
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DEC |
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Commanded FPA pointing declination (deg) |
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CD1_1 |
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Translation matrix element |
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CD1_2 |
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Translation matrix element |
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CD2_1 |
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Translation matrix element |
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CD2_2 |
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Translation matrix element |
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EXTNAME |
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Format: CCD row-CCD column.quadrant id, e.g. 2.3-H |
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INSTRUME |
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VIS instrument |
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EXPTIME |
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Commanded integration time in seconds, e.g. 565.0 |
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DETECTOR |
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ToFill |
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GAIN |
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Maximum equivalent gain (e-/ADU) |
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RDNOISE |
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Read out Noise |
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QE |
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Quantum Efficiency |
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DC |
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ToFill |
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PIXSIZE |
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ToFill |
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PIXSCALE |
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ToFill |
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CCDID |
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e.g. Detector ID and quad, e.g. 1-1.H’ … ‘6-6.E’ |
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QUADID |
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e.g. Quadrant ID, e.g. ‘E’, ‘F’, ‘G’ or ‘H’ |
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PRESCANX |
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number of serial prescan pixels, e.g 51 |
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OVRSCANX |
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number of serial overscan pixels, e.g 20 |
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DETSEC |
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ToFill |
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ASEC |
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ToFill |
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DSEC |
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ToFill |
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TSEC |
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ToFill |
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BSEC |
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ToFill |
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CSEC |
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ToFill |
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MAXLIN |
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ToFill |
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SATURATE |
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Saturation Level (ADU) |
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NON_LIN |
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ToFill |
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RON_STD |
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ToFill |
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BIAS_LVL |
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Bias Level |
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ADC_MAX |
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ToFill |
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PC1_1 |
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Coordinate transformation matrix element |
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PC1_2 |
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Coordinate transformation matrix element |
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PC2_1 |
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Coordinate transformation matrix element |
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PC2_2 |
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Coordinate transformation matrix element |
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CDELT1 |
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[deg] Coordinate increment at reference |
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CDELT2 |
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[deg] Coordinate increment at reference |
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CUNIT1 |
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Physical units of CRVAL1 |
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CUNIT2 |
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Physical units of CRVAL2 |
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LONPOLE |
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[deg] Native longitude of celestial pol |
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LATPOLE |
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[deg] Native latitude of celestial pole |
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RADESYS |
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Astrometric system |
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DATE-OBS |
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UTC Date of observation (start), e.g. ‘2014-03-15T09:30:09.313’ |
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CHECKSUM |
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HDU checksum updated 2018-11-15T12:07:22 |
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DATASUM |
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data unit checksum updated 2018-11-15T12:07:22 |
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NBIAS |
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Number of Bias Frames |
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COMBMETH |
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Combination Method Used |
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NORMMETH |
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Normalisation Method |
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END |
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