LAST Data Products/pipeline I / Headers

This page describes the FITS image headers of LAST data products.

Header keywords

Here we provide descriptions of special header keywords. Group corresponds to the general topic or theme that keywords belong to, and Tables indicate in which tables the keyword is present (R-Raw; E-Epoch, V-Visit; ...)

Group	Tables	Key	Units	Description
FITS structure	REV	SIMPLE	bool	Indicates that the file conforms to the FITS standard.
FITS structure	REV	BITPIX	bit	Number of bits per data pixel. Negative values indicate floating-point data.
FITS structure	REV	NAXIS		Number of data axes in the image.
FITS structure	REV	NAXIS1	pixel	Length of image axis 1.
FITS structure	REV	NAXIS2	pixel	Length of image axis 2.
FITS structure	REV	EXTEND	bool	Indicates that the FITS file may contain extensions.
FITS structure	REV	LONGSTRN	string	Long-string convention used for FITS header values continued over multiple cards.
FITS checksum	EV	CHECKSUM	string	FITS header/data checksum keyword.
FITS checksum	EV	DATASUM	string	FITS data checksum keyword.
File info	REV	FILENAME	string	Name of the FITS file.
File info	REV	CRDATE	UTC	UTC date and time when the file was created.
Project info	REV	PROJNAME	string	LAST project/system name.
Project info	REV	FULLPROJ	string	Full LAST project/node/mount/camera identifier (e.g., 'LAST.01.08.03').
Project info	REV	NODENUMB		LAST node number.
Project info	REV	TIMEZONE	h	Observatory/local time-zone offset.
Project info	REV	MOUNTNUM		Mount number.
Software	REV	GITASTRP	string	Git version or branch identifier of the astronomy processing/control software.
Software	REV	GIT_CAMR	string	Git version or branch identifier of the camera-control software.
Software	REV	GITFOCUS	string	Git version or branch identifier of the focus-control software.
Software	EV	PIPEVER	string	Pipeline version or Git identifier.
Observatory	REV	OBSLON	deg	Longitude of the observatory.
Observatory	REV	OBSLAT	deg	Latitude of the observatory.
Observatory	REV	OBSALT	m	Height of the observatory above sea level.
Environment	REV	MNTTEMP	deg C	Temperature measured by the mount sensors.
Time	REV	JD_START	JD	Julian day of the command starting the series of exposures (i.e., in a visit this corresponds to a time before the start of the first saved image).
Time	EV	JD	JD	Julian day at exposure start.
Time	EV	MIDJD	JD	Julian day of mid-exposure, or weighted mean observation time for coadds.
Time	V	MINJD	JD	Mid-exposure Julian day of the first coadded observation.
Time	V	MAXJD	JD	Mid-exposure Julian day of the last coadded observation.
Time	REV	DATE-OBS	UTC	UTC date and time at exposure start.
Time	EV	TIME	string	Exposure time string used in file and directory naming.
Time	REV	LST	deg	Local sidereal time at exposure start.
Pointing	REV	RA	deg	J2000 right ascension for image center. For raw image, this is the best guess including telescope offset, for processed data this is the solved RA, Dec of the image center.
Pointing	REV	DEC	deg	J2000 declination (like RA).
Pointing	REV	EQUINOX	yr	Equinox of the coordinate system.
Pointing	REV	M_RA	deg	Mount physical/apparent pointing right ascension.
Pointing	REV	M_HA	deg	Mount physical/apparent pointing hour angle.
Pointing	REV	M_DEC	deg	Mount physical/apparent pointing declination.
Pointing	REV	M_AZ	deg	Mount physical/apparent pointing azimuth.
Pointing	REV	M_ALT	deg	Mount physical/apparent pointing altitude.
Pointing	REV	M_JRA	deg	Mount center J2000 right ascension
Pointing	REV	M_JDEC	deg	Mount center J2000 declination.
Pointing	REV	M_ARA	deg	Mount apparent equinox-of-date right ascension.
Pointing	REV	M_AHA	deg	Mount apparent equinox-of-date hour angle.
Pointing	REV	M_ADEC	deg	Mount apparent equinox-of-date declination.
Pointing	REV	M_ADRA	deg	Mount apparent right ascension including distortion correction (pointing model).
Pointing	REV	M_ADHA	deg	Mount apparent hour angle including distortion correction (pointing model).
Pointing	REV	M_ADDEC	deg	Mount apparent declination including distortion correction (pointing model).
Pointing	REV	AIRMASS		Hardie airmass at the time of observation.
Tracking	REV	TRK_RA	arcsec s $^{-1}$	Tracking speed in right ascension.
Tracking	REV	TRK_DEC	arcsec s $^{-1}$	Tracking speed in declination.
Focus	REV	FOCUS	step	Current focuser position.
Focus	REV	PRVFOCUS	step	Previous focuser position.
Image info	REV	IMTYPE	string	Image type, e.g., science image.
Image info	REV	OBJECT	string	Target or object name.
Image info	REV	FILTER	string	Filter used for the exposure.
Image info	REV	COUNTER		Exposure or frame counter.
Image info	REV	EXPTIME	s	Exposure time.
Image info	V	MEXPTIME	s	Mean exposure time of images from which the coadd image was composed.
Image scaling	REV	BZERO		FITS data offset used for scaling stored pixel values.
Image scaling	REV	BSCALE		FITS data scale factor applied to stored pixel values.
Camera	REV	EXPMODE	string	Camera exposure mode.
Camera	REV	GAIN	$e^{-}$ /ADU	Detector gain. Exact units should be verified from the camera configuration.
Camera	REV	READNOI	$e^{-}$	Detector read noise. Exact units should be verified from the camera configuration.
Camera	REV	DARKCUR	$ADU$ $s^{-1}$ pix $^{-1}$	Detector dark current. Exact units should be verified from the camera configuration.
Camera	REV	SATURVAL	ADU	Saturation value.
Camera	REV	NONLIN	ADU	Approximate non-linearity threshold.
Camera	REV	BINX	pixel	Detector binning factor along the X axis.
Camera	REV	BINY	pixel	Detector binning factor along the Y axis.
Camera	REV	CAMNUM		Camera number.
Camera	REV	CAMNAME	string	Camera name or camera identifier.
Camera	REV	CAMTEMP	deg C	Camera sensor temperature.
Camera	REV	CAMCOOL	percent	Camera cooling power.
Camera	REV	CAMMODE		Camera readout mode.
Camera	REV	CAMGAIN		Camera gain setting.
Camera	REV	CAMOFFS	ADU	Camera offset level.
Pipeline	EV	LEVEL	string	Data product processing level.
Pipeline	EV	SUBLEVEL	string	Processing sub-level of the data product.
Pipeline	EV	VERSION	string	Data product version.
Identification	EV	ID_RAW	string	Unique identifier of the raw image. Note that this doesn't included in the raw image header.
Identification	EV	ID_DARK	string	Unique identifier of the dark calibration image.
Identification	EV	ID_FLAT	string	Unique identifier of the flat-field calibration image.
Identification	EV	ID_PROC	string	Unique identifier of the processed image (for visit coadd, this is available but meaningless).
Identification	V	ID_COADD	string	Unique identifier of the coadded image.
Identification	V	ID_PROCF	string	ID of the first processed image in the visit coadd.
Identification	V	ID_PROCL	string	ID of the last processed image in the visit coadd.
Identification	EV	CCDID		CCD identifier.
Identification	EV	SUBDIR	string	Subdirectory name associated with the visit.
Identification	EV	FIELDID	string	Field or target identifier.
Identification	EV	DIRDAY	day	Day component of the data directory date.
Identification	EV	DIRMON	month	Month component of the data directory date.
Identification	EV	DIRYEAR	yr	Year component of the data directory date.
Image region	EV	CROPID		Crop identifier.
Image region	EV	LIGHTSEC	pixel	Section of the original image used as the light-sensitive image region.
Image region	EV	OVERSCAN	pixel	Section of the original image corresponding to the overscan region.
Image region	EV	CCDSEC	pixel	Pixel section of the CCD represented in this image.
Image region	EV	ORIGSEC	pixel	Pixel section in the original full-frame image corresponding to this cropped image.
Image region	EV	ORIGUSEC	pixel	Pixel section in the original full-frame image corresponding to the unique (i.e., no overlap) region of this cropped image.
Image region	EV	UNIQSEC	pixel	Pixel section of the unique (non overlapping) part of this cropped image (corresponding to ORIGUSEC).
Calibration	EV	BIAS_IM	string	Bias or dark calibration image used in processing.
Calibration	EV	FLAT_IM	string	Flat-field calibration image used in processing.
Calibration	EV	ORIGGAIN	$e^{-}$ /ADU	Original detector gain used before or during calibration. Exact units should be verified.
Background	EV	MEANBCK	$e^{-}$	Mean background level.
Background	EV	MEDBCK	$e^{-}$	Median background level.
Background	EV	STDBCK	$e^{-}$	Standard deviation of the background level.
Background	EV	MINBCK	$e^{-}$	Minimum estimated background level.
Background	EV	MAXBCK	$e^{-}$	Maximum estimated background level.
Variance	EV	MEANVAR	$e^{-}$ $^2$	Mean variance estimate.
Variance	EV	MEDVAR	$e^{-}$ $^2$	Median variance estimate.
Sources	EV	N_STARS		Number of stars found and measured in the image.
Matched	EV	M_CHI2D		Median of the best-fit chi-square of all sources in the image.
Matched	EV	RP_MRMS	mag	Minimum (asymptotic) RMS of relative photometry over all epochs in visit.
Matched	EV	RP_MMRMS	mag	Magnitude of the minimum (asymptotic) RMS of relative photometry over all epochs in visit.
Astrometry	EV	AST_NSRC		Number of astrometric sources.
Astrometry	EV	AST_ARMS	arcsec	Astrometric asymptotic RMS.
Astrometry	EV	AST_ERRM	arcsec	Astrometric error on the mean.
WCS	EV	CTYPE1	string	WCS projection type for image axis 1.
WCS	EV	CTYPE2	string	WCS projection type for image axis 2.
WCS	EV	WCSAXES		Number of WCS axes.
WCS	EV	RADESYS	string	Astrometric reference system.
WCS	EV	LONPOLE	deg	Native longitude of the celestial pole.
WCS	EV	LATPOLE	deg	Native latitude of the celestial pole.
WCS	EV	CUNIT1	string	World-coordinate unit for axis 1.
WCS	EV	CUNIT2	string	World-coordinate unit for axis 2.
WCS	EV	CRPIX1	pixel	Reference pixel coordinate on image axis 1.
WCS	EV	CRPIX2	pixel	Reference pixel coordinate on image axis 2.
WCS	EV	CRVAL1	deg	World coordinate at the reference pixel for axis 1.
WCS	EV	CRVAL2	deg	World coordinate at the reference pixel for axis 2.
WCS	EV	CD%d_%d	deg pix $^{-1}$	Linear WCS transformation matrix element.
WCS	EV	PIXSCALE	arcsec pix $^{-1}$	Pixel scale.
WCS	EV	ROTAT	deg	Image rotation angle.
WCS distortion	EV	PV%d_%d		TPV astrometric distortion coefficient. The first index is the WCS axis and the second index is the TPV polynomial coefficient index.
Image corners	EV	RA%d	deg	Right ascension of image corner %d.
Image corners	EV	DEC%d	deg	Declination of image corner %d.
Image corners	EV	RAU%d	deg	Right ascension of unique image-region corner %d.
Image corners	EV	DECU%d	deg	Declination of unique image-region corner %d.
PSF info	EV	FWHM	arcsec	FWHM measured by the radial cumulative sum of the PSF flux crossing half the total flux, i.e., effective radius of half the energy.
PSF info	EV	PSF_FITN		Normalization of Gaussian fit, where the PSF is normalized to unity.
PSF info	EV	PSF_FITA	arcsec	$\sigma$-width of the semi-major axis of the best-fit Gaussian.
PSF info	EV	PSF_FITB	arcsec	$\sigma$-width of the semi-minor axis of the best-fit Gaussian.
PSF info	EV	PSF_FITT	deg	Rotation angle of the best-fit 2D Gaussian measured counterclockwise from the X-axis.
PSF info	EV	PSF_NST		Number of stars used for PSF estimation.
PSF info	EV	PSF_NPK		Number of detected peaks in the PSF.
PSF info	EV	PSF_PKR		Ratio between the highest peak in the PSF and the second highest peak.
PSF info	EV	PSF_DPK	pixel	Distance between the two highest peaks in the PSF.
Pixels	EV	UPIX_PAR		Healpix unique identifier (partition: NSide= $2^3$).
Pixels	EV	UPIX_LOW		Healpix unique identifier (low: NSide= $2^8$).
Pixels	EV	UPIX_HIG		Healpix unique identifier (high: NSide= $2^{16}$).
Shape diagnostics	EV	MED_X2	pix $^2$	Median second moment, over all stars, in the X direction.
Shape diagnostics	EV	MED_Y2	pix $^2$	Median second moment, over all stars, in the Y direction.
Shape diagnostics	EV	MED_XY	pix $^2$	Median cross second moment, over all stars.
Photometry	EV	MAG_95Q	mag	95th-percentile magnitude of selected sources.
Legacy Photometry	EV	PH_ZP	mag	Photometric zero point, based on legacy fitting method.
Legacy Photometry	EV	PH_COL1	mag	First-order photometric color term (legacy)
Legacy Photometry	EV	PH_MEDC	mag	Median color of sources used for photometric calibration.
Legacy Photometry	EV	PH_RMS	mag	RMS scatter of the photometric calibration residuals.
Legacy Photometry	EV	PH_NSRC		Number of sources used for photometric calibration.
Legacy Photometry	EV	PH_MAGSY	string	Magnitude system used for photometric calibration.
Photometry	EV	LIMMAG	mag	Limiting magnitude.
Photometry	EV	BACKMAG	mag arcsec $^{-2}$	Background surface brightness.
Photometry	EV	PH_MAGT	string	Magnitude type (e.g., MAG_APER_3) used for photometric calibration.
Photometry	EV	PH_MAGTE	string	Magnitude-error column or type used for photometric calibration.
Aperture correction	EV	APCOR_A%d	mag	Aperture-correction coefficient or fitted parameter %d.
Aperture correction	EV	APCOR_PS	mag	Aperture correction associated with the PSF magnitude or PSF-to-aperture offset.
Aperture correction	EV	APCOR_N		Number of sources used to estimate the aperture correction.
Coaddition	EV	NCOADD		Number of coadded images.
Coaddition	EV	COADDOP	string	Coaddition method.
Coaddition	EV	AVNCOADD		Mean number of last-step coadded images per pixel.
Coaddition	EV	MINCOADD		Minimum number of last-step coadded images per pixel.
Moving object	EV	GM_RATEX	pix s $^{-1}$	Global fitted motion rate along the X/image-axis direction. Exact units should be verified.
Moving object	EV	GM_STDX	pix	Standard deviation or uncertainty of the fitted motion in the X/image-axis direction. Exact units should be verified.
Moving object	EV	GM_RATEY	pix s $^{-1}$	Global fitted motion rate along the Y/image-axis direction. Exact units should be verified.
Moving object	EV	GM_STDY	pix	Standard deviation or uncertainty of the fitted motion in the Y/image-axis direction. Exact units should be verified.
Photometric transmission	EV	PT_RMS	mag	RMS residual of the photometric-transmission fit.
Photometric transmission	EV	PT_ARMS	mag	Asymptotic RMS of the photometric-transmission fit.
Photometric transmission	EV	PT_CHI2		Chi-square statistic of the photometric-transmission fit.
Photometric transmission	EV	PT_DOF		Degrees of freedom of the photometric-transmission fit.
Photometric transmission	EV	PT_NCALI		Number of calibrating sources used in the photometric-transmission fit.
Photometric transmission	EV	PT_SUCC	bool	Indicates whether the photometric-transmission fit succeeded.
Photometric transmission	EV	PT_AREF	string	Reference atmosphere or atmospheric model used by the photometric-transmission fit.
Photometric transmission	EV	PT_SPEC	string	Reference spectral/catalogue source used by the photometric-transmission fit.
Photometric transmission	EV	PT_%d_N	string	Name of photometric-transmission model component %d.
Photometric transmission	EV	PT_%d_V%d		Value of parameter %d for photometric-transmission model component %d.
Photometric transmission	EV	PT_%d_F%d	bool/int	Flag indicating if parameter %d of photometric-transmission model component %d was held fixed (false) or fitted (true).