Vis Stacked Frame Product¶
Metadata¶
Data product name |
DpdVisStackedFrame |
Data product custodian |
VIS |
Name of the Schema file |
|
Processing Element(s) creating/using the data product |
VIS_science_xml_out |
Processing function using the data product |
Proposed for inclusion in EAS/SAS¶
Yes
Data product elements¶
Header |
object of type sys:genericHeader |
Data |
object of type vis:visStackedFrame |
QualityFlags |
object of type dqc:sqfPlaceHolder |
Parameters |
object of type ppr:genericKeyValueParameters |
Detailed description of the data product¶
The VIS PF provides stacked images which individual VIS dither is combined using SWarp. If an exposure is invalid during the processing with ‘Header.AutomatedValidationStatus=INVALID’, it will be excluded from the stacks.
The Stackedframe product consisting of 3 FITS files by exposure:
Stacked VIS image,
Weight MAP
Stack PSF
Since PF-18, exposure are background substracted before being combined. Therefore, no background map is not provided.
The background substraction can be desactivate in the Vis Configuration File Product for special processing. A background map is then produced in this special case.
Calibrated VIS stacked image¶
The calibrated stacked image is a single extension FITS file containing the Science image.
By default, the option COMBINE TYPE=CLIPPED is used (D. Gruen et al 2014).
The tangent point (Calabretta & Greisen 2002) of the output image is computed by SWarp software with the option “CENTER_TYPE all”. Therefore, the size of this image and its tangent point is for the moment not pre-defined, and can vary based on the coverage of the input dithers. The output tangent point is approximately equal to the geometric average of the tangent point of the input images.
The fluxes in each pixel of the SCI extension are rescaled to have a zero point of 23.9 AB magnitudes with an effective exposure time of 1s.
The input data products (SCI, RMS, and FLG) are resampled to constant pixel scale over the focal plane of 0.1” / pixel.
The input images are background subtracted using the background of the Vis Calibrated Quad Frame Product.
Name of file:
EUC_VIS_SWL_STK-000-000000-0000000__[YYYYMMDDThhmmss.s]Z.fits.gz
where the date is the production date.
Note
This definition is a change introduced by PF-18. Before this version, stack image was a multiple extension FITS with 3 extensions : Science, RMS map, Flag map. The description of this extension is kept for documentation.
The old RMS and FLG extension definision was:
RMS: As for the calibrated VIS individual images, the RMS map contains standard deviation at each pixel in the corresponding Science image, expressed as the absolute standard deviation.
FLG: For the stacked images, the value of the Flagmap is 0 for good data, 1 otherwise. Flags are stored as eight-bit unsigned integers.
Data Header¶
Primary Header |
|
|---|---|
SIMPLE |
file does conform to FITS standard |
BITPIX |
number of bits per data pixel |
NAXIS |
number of data axes |
EXTEND |
FITS dataset may contain extensions |
EQUINOX |
Mean equinox |
RADESYS |
Astrometric system |
CTYPE1 |
WCS projection type for this axis |
CUNIT1 |
Axis unit |
CRVAL1 |
World coordinate on this axis |
CRPIX1 |
Reference pixel on this axis |
CD1_1 |
Linear projection matrix |
CD1_2 |
Linear projection matrix |
CTYPE2 |
WCS projection type for this axis |
CUNIT2 |
Axis unit |
CRVAL2 |
World coordinate on this axis |
CRPIX2 |
Reference pixel on this axis |
CD2_1 |
Linear projection matrix |
CD2_2 |
Linear projection matrix |
EXPTIME |
Maximum equivalent exposure time (s) |
GAIN |
Maximum equivalent gain (e-/ADU) |
SATURATE |
Saturation Level (ADU) |
SOFTNAME |
The software that processed those data |
SOFTVERS |
Version of the software |
SOFTDATE |
Release date of the software |
SOFTAUTH |
Maintainer of the software |
SOFTINST |
Institute |
AUTHOR |
Who ran the software |
ORIGIN |
Where it was done |
DATE |
When it was started (GMT) |
COMBINET |
COMBINE_TYPE config parameter for SWarp |
RESAMPT1 |
RESAMPLING_TYPE config parameter |
CENTERT1 |
CENTER_TYPE config parameter |
PSCALET1 |
PIXELSCALE_TYPE config parameter |
RESAMPT2 |
RESAMPLING_TYPE config parameter |
CENTERT2 |
CENTER_TYPE config parameter |
PSCALET2 |
PIXELSCALE_TYPE config parameter |
OBS_ID |
OSS_obsid |
DITHOBS |
OSS_inObsId |
EXPNUM |
Exposure Id in dither |
MAGZEROP |
zero-point |
PHOT_ERR |
self calibration photometric error |
PHOTIRMS |
self calibration mag dispersion RMS |
APERCORR |
self calibration aperture correction MAG_50pix |
APCORRMS |
self calibration aperture correction rms error |
Extension Header |
|
|---|---|
XTENSION |
Image extension |
BITPIX |
number of bits per data pixel |
NAXIS |
number of data axes |
NAXIS1 |
Number of pixels along this axis |
NAXIS2 |
Number of pixels along this axis |
PCOUNT |
number of parameters |
GCOUNT |
number of groups |
EXTEND |
This file may contain FITS extensions |
EQUINOX |
Mean equinox |
RADESYS |
Astrometric system |
CTYPE1 |
WCS projection type for this axis |
CUNIT1 |
Axis unit |
CRVAL1 |
World coordinate on this axis |
CRPIX1 |
Reference pixel on this axis |
CD1_1 |
Linear projection matrix |
CD1_2 |
Linear projection matrix |
CTYPE2 |
WCS projection type for this axis |
CUNIT2 |
Axis unit |
CRVAL2 |
World coordinate on this axis |
CRPIX2 |
Reference pixel on this axis |
CD2_1 |
Linear projection matrix |
CD2_2 |
Linear projection matrix |
EXPTIME |
Maximum equivalent exposure time (s) |
GAIN |
Maximum equivalent gain (e-/ADU) |
SATURATE |
Saturation Level (ADU) |
SOFTNAME |
The software that processed those data |
SOFTVERS |
Version of the software |
SOFTDATE |
Release date of the software |
SOFTAUTH |
Maintainer of the software |
SOFTINST |
Institute |
AUTHOR |
Who ran the software |
ORIGIN |
Where it was done |
DATE |
When it was started (GMT) |
COMBINET |
COMBINE_TYPE config parameter for SWarp |
RESAMPT1 |
RESAMPLING_TYPE config parameter |
CENTERT1 |
CENTER_TYPE config parameter |
PSCALET1 |
PIXELSCALE_TYPE config parameter |
RESAMPT2 |
RESAMPLING_TYPE config parameter |
CENTERT2 |
CENTER_TYPE config parameter |
PSCALET2 |
PIXELSCALE_TYPE config parameter |
OBS_ID |
OSS_obsid |
DITHOBS |
OSS_inObsId |
EXPNUM |
Exposure Id in dither |
MAGZEROP |
zero-point |
PHOT_ERR |
self calibration photometric error |
PHOTIRMS |
self calibration mag dispersion RMS |
APERCORR |
self calibration aperture correction MAG_50pix |
APCORRMS |
self calibration aperture correction rms error |
EXTNAME |
Data type (SCI, RMS, or FLG) |
Weight Map¶
The weight map is the output weight produced by SWarp. It is the stack weight of the individual exposure. See the SWarp manual for more details.
Name of file:
EUC_VIS_SWL-WGT-000-000000-0000000__[YYYYMMDDThhmmss.s]Z.fits.gz
where the date is the production date.
Data Header¶
Primary Header |
|
|---|---|
SIMPLE |
This is a FITS file |
BITPIX |
|
NAXIS |
|
NAXIS1 |
Number of pixels along this axis |
NAXIS2 |
Number of pixels along this axis |
EXTEND |
This file may contain FITS extensions |
EQUINOX |
Mean equinox |
RADESYS |
Astrometric system |
CTYPE1 |
WCS projection type for this axis |
CUNIT1 |
Axis unit |
CRVAL1 |
World coordinate on this axis |
CRPIX1 |
Reference pixel on this axis |
CD1_1 |
Linear projection matrix |
CD1_2 |
Linear projection matrix |
CTYPE2 |
WCS projection type for this axis |
CUNIT2 |
Axis unit |
CRVAL2 |
World coordinate on this axis |
CRPIX2 |
Reference pixel on this axis |
CD2_1 |
Linear projection matrix |
CD2_2 |
Linear projection matrix |
EXPTIME |
Maximum equivalent exposure time (s) |
GAIN |
Maximum equivalent gain (e-/ADU) |
SATURATE |
Saturation Level (ADU) |
SOFTNAME |
The software that processed those data |
SOFTVERS |
Version of the software |
SOFTDATE |
Release date of the software |
SOFTAUTH |
Maintainer of the software |
SOFTINST |
Institute |
AUTHOR |
Who ran the software |
ORIGIN |
Where it was done |
DATE |
When it was started (GMT) |
COMBINET |
COMBINE_TYPE config parameter for SWarp |
RESAMPT1 |
RESAMPLING_TYPE config parameter |
CENTERT1 |
CENTER_TYPE config parameter |
PSCALET1 |
PIXELSCALE_TYPE config parameter |
RESAMPT2 |
RESAMPLING_TYPE config parameter |
CENTERT2 |
CENTER_TYPE config parameter |
PSCALET2 |
PIXELSCALE_TYPE config parameter |
Stack PSF¶
The PSF computation is done in the same way as Vis PSF Model Product on the stack image. In result the PSF file is a grid image of 9 by 9 PSF which correspond to the check image snapshot of PSFEx.
Data Header¶
SIMPLE |
|
BITPIX |
|
NAXIS |
|
NAXIS1 |
BYTES PER ROW |
NAXIS2 |
NUMBER OF ROWS |
CD1_1 |
pixel scale in deg |
CD1_2 |
pixel scale in deg |
CD2_1 |
pixel scale in deg |
CD2_2 |
pixel scale in deg |
TELESCOP |
|
INSTRUME |
|
PIXSIZE |
pixel size in microns |
ECPSIZE |
nominal Euclid pixel size in microns |
OVERSAMP |
oversampling factor for this PSF |
Background Map¶
Note
In DR1 and after the background is always subtracted before the stacking. Therefore this product is not available in DR1.
As it can be available if a special processing is done, the description is kept.
The background map delivered corespond to the background map from SExtractor.
When the background is removed before the stacking, the background map is not produce.
Primary Header |
|
|---|---|
SIMPLE |
This is a FITS file |
BITPIX |
|
NAXIS |
|
NAXIS1 |
Number of pixels along this axis |
NAXIS2 |
Number of pixels along this axis |
EXTEND |
This file may contain FITS extensions |
EQUINOX |
Mean equinox |
RADESYS |
Astrometric system |
CTYPE1 |
WCS projection type for this axis |
CUNIT1 |
Axis unit |
CRVAL1 |
World coordinate on this axis |
CRPIX1 |
Reference pixel on this axis |
CD1_1 |
Linear projection matrix |
CD1_2 |
Linear projection matrix |
CTYPE2 |
WCS projection type for this axis |
CUNIT2 |
Axis unit |
CRVAL2 |
World coordinate on this axis |
CRPIX2 |
Reference pixel on this axis |
CD2_1 |
Linear projection matrix |
CD2_2 |
Linear projection matrix |
EXPTIME |
Maximum equivalent exposure time (s) |
GAIN |
Maximum equivalent gain (e-/ADU) |
SATURATE |
Saturation Level (ADU) |
SOFTNAME |
The software that processed those data |
SOFTVERS |
Version of the software |
SOFTDATE |
Release date of the software |
SOFTAUTH |
Maintainer of the software |
SOFTINST |
Institute |
AUTHOR |
Who ran the software |
ORIGIN |
Where it was done |
DATE |
When it was started (GMT) |
COMBINET |
COMBINE_TYPE config parameter for SWarp |
RESAMPT1 |
RESAMPLING_TYPE config parameter |
CENTERT1 |
CENTER_TYPE config parameter |
PSCALET1 |
PIXELSCALE_TYPE config parameter |
RESAMPT2 |
RESAMPLING_TYPE config parameter |
CENTERT2 |
CENTER_TYPE config parameter |
PSCALET2 |
PIXELSCALE_TYPE config parameter |
OBS_ID |
|
DITHOBS |
|
EXPNUM |
|
MAGZEROP |
zero-point |
PHOT_ERR |
self calibration photometric error |
PHOTIRMS |
self calibration mag dispersion RMS |
APERCORR |
self calibration aperture correction MAG_50pix |
APCORRMS |
self calibration aperture correction rms error |