pm-EXPID

Summary:

PlateMaker data.

Naming Convention:

pm-EXPID.fits, where EXPID is the zero-padded 8-digit exposure ID.

Regex:

pm-[0-9]{8}\.fits

File Type:

FITS, 1 MB

Contents

Number	EXTNAME	Type	Contents
HDU0	PM	IMAGE	Header Keywords
HDU1	PMGSTARS	BINTABLE	Guide stars
HDU2	PMGWCS	BINTABLE	Guider WCS
HDU3	PMFIDPOS	BINTABLE	Predicted fiducial postitons
HDU4	PMPOSPOS	BINTABLE	Predicted fiber positions
HDU5	PMCNTPOS	BINTABLE	Predicted center-of-travel positions
HDU6	PMFIBMAP	BINTABLE	Positions after calibration

FITS Header Units

HDU0

EXTNAME = PM

The data contents are a dummy payload that should not be used. The most important header keywords are:

• CENTER: Apparent telescope coordinates needed to place field center at center of the focal plane.

• GCENTER: Pointing corrections after computing astrometric solution.

• GHEXROT: Absolute hexapod rotation and rate after computing astrometric solution. Rate is not used.

• PMNFSADC: Absolute ADC angles.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	1	int	length of data axis 1
DEVICE	GUIDE8	str	Device/controller name
UNIT	8	int	Unit number/letter
UNITTYPE	GUIDE	str	Image Sources/Component
MODULE	GUIDE	str	Image Sources/Component
EXPID	182039	int	Exposure number
EXPFRAME	0	int	Frame number
FRAMES	1	int	Number of Frames in Archive
TILEID	4361	int	DESI Tile ID
FIBASSGN	/data/tiles/SVN_tiles/004/fiberassign-004361.fits.gz	str	Fiber assign
FLAVOR	SCIENCE	str	Observation type
SEQUENCE	DESI	str	OCS Sequence name
OBJECT	start_loop	str	Object name
PURPOSE	Main Survey	str	Purpose of observing night
PROGRAM	DARK	str	Program name
PROPID	2020B-5000	str	Proposal ID
OBSERVER	Rodrigo Calderon, Khaled Said	str	Names of observers
LEAD	Martin Landriau	str	Lead observer
INSTRUME	DESI	str	Instrument name
OBSERVAT	KPNO	str	Observatory name
OBS-LAT	31.96403	str	[deg] Observatory latitude
OBS-LONG	-111.59989	str	[deg] Observatory east longitude
OBS-ELEV	2097.0	float	[m] Observatory elevation
TELESCOP	KPNO 4.0-m telescope	str	Telescope name
CORRCTOR	DESI Corrector	str	Corrector Identification
NIGHT	20230524	int	Observing night
TIMESYS	UTC	str	Time system used for date-obs
DATE-OBS	2023-05-25T08:34:19.830256	str	[UTC] Observation data and start time
TIME-OBS	08:34:19.830256	str	[UTC] Observation start time
MJD-OBS	60089.35717396	float	Modified Julian Date of observation
OPENSHUT	2023-05-25T08:34:19.830256	str	[s] Time shutter opened
ST	17:18:55.6097	str	Local Sidereal time at observation start (HH:MM
EXPTIME	15.0	float	[s] Actual exposure time
ACQTIME	15.0	float	[s] acqusition image exposure time
REQRA	244.33	float	[deg] Requested right ascension (observer input
REQDEC	15.297	float	[deg] Requested declination (observer input)
FOCUS	1331.8,-319.4,-468.0,-11.5,32.4,174.9	str	Telescope focus settings
TRUSTEMP	15.633	float	[deg] Average Telescope truss temperature (only
PMIRTEMP	15.188	float	[deg] Average primary mirror temperature (nit,e
EPOCH	2000.0	float	Epoch of observation
EQUINOX	2000.0	float	Equinox of selected coordinate reference frame
MOUNTAZ	223.47215	float	[deg] Mount azimuth angle
MOUNTDEC	15.29368	float	[deg] Mount declination
MOUNTEL	68.266626	float	[deg] Mount elevation angle
MOUNTHA	15.314189	float	[deg] Mount hour angle
SKYDEC	15.29368	float	[deg] Telescope declination (pointing on sky)
SKYRA	244.327071	float	[deg] Telescope right ascension (pointing on sk
TARGTDEC	15.29368	float	[deg] Target declination (to TCS)
TARGTRA	244.327071	float	[deg] Target right ascension (to TCS)
USEETC	T	bool	ETC data available if true
ACQCAM	GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8	str	Acquisition cameras used
GUIDECAM	GUIDE0,GUIDE2,GUIDE3,GUIDE5,GUIDE7,GUIDE8	str	Guide cameras used for t
FOCUSCAM	FOCUS1,FOCUS4,FOCUS6,FOCUS9	str	Focus cameras used for this exposure
SKYCAM	SKYCAM0,SKYCAM1	str	Sky cameras used for this exposure
USESKY	T	bool	DOS Control: use Sky Monitor
USEFOCUS	T	bool	DOS Control: use focus
HEXPOS	1331.8,-319.4,-468.0,-11.5,32.4,174.9	str	Hexapod position
USEGUIDR	T	bool	DOS Control: use guider
USEDONUT	T	bool	DOS Control: use donuts
WCSAXES	2	int
RADESYS	FK5	str	Coordinate reference frame of major/minor axes
CTYPE1	RA—TAN	str
CTYPE2	DEC–TAN	str
CD1_1	-3.521e-05	float
CD1_2	-4.3757e-05	float
CD2_1	-4.7625e-05	float
CD2_2	3.235e-05	float
CRPIX1	1036.7	float
CRPIX2	522.17	float
CRVAL1	245.6899	float
CRVAL2	14.4297	float
TNFSPROC	8.9117	float	[s] PlateMaker NFSPROC processing time
TGFAPROC	5.0955	float	[s] PlateMaker GFAPROC processing time
FILENAME	/exposures/desi/20230524/00182039/guide-00182039-0000.fits.fz	str	Name
SHAPE	1032,2248	str
DTYPE	uint16	str
DOSVER	trunk	str	DOS software version
OCSVER	1.2	float	OCS software version
CONSTVER	DESI:CURRENT	str	Constants version
INIFILE	/data/msdos/dos_home/architectures/kpno/desi.ini	str	DOS Configuration
CENTER	244.32707,15.29368	str	Platemaker nfsproc center (ra, dec)
GCENTER	8.27,53.17	str	Platemaker gfaproc center (ra, dec)
GHEXROT	165.2,0.38	str	Platemaker gfaproc hexapod rotation (initial an
PMNFSADC	28.06,52.49	str	Platemaker nfsproc adc angles
REQTIME	1860.0	float	[s] Requested exposure time
ROLE	GUIDERMAN	str
OVERSCAN	50	int
DEVICEID	dev04	str	GFA device id (serial number)
GAMBNTT	10.313	float	[deg C] GFA ambient temperature
GFPGAT	32.748	float	[deg C] GFA fpga temperature
GFILTERT	10.281	float	[deg C] GFA filter temperature
GCOLDTEC	10.479	float	[deg C] GFA cold Peltier temperature
GHOTTEC	10.236	float	[deg C] GFA hot Peltier temperature
GCCDTEMP	10.479	float	[deg C] GFA CCD temperature
GCAMTEMP	10.281	float	[deg C] GFA camera temperature
GCAMHUM	3.346	float	[%/100] GFA camera humidity
GHUMID2	3.346	float	[%/100] GFA humidity sensor 2
GHUMID3	0.0	float	[%/100]GFA humidity sensor 3
GEXPMODE	normal	str	GFA readout mode (loop/normal)
READOUT	OK	str
ROIS	469.4,1724.9776.3,505.3	str
CHECKSUM	ZjADfi99ZiACfi79	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	1072693248	str	data unit checksum updated 2023-05-25T08:35:47

Data: FITS image [float64, 1]

HDU1

EXTNAME = PMGSTARS

Table of guide stars to be used for guiding.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	86	int	width of table in bytes
NAXIS2	29	int	number of rows in table
EXPID	182039	int
MODULE	GUIDESTARS	str
CHECKSUM	8qKfAnKe1nKe8nKe	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	612635513	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
GFA_LOC	char[6]		Location on focal plane of GFA (same numbering convention as petal location)
RA	float64	deg	Barycentric Right Ascension in ICRS
DEC	float64	deg	Barycentric declination in ICRS
ROW	float64		GFA pixel row coordinate
COL	float64		GFA pixel col coordinate
RA_IVAR	float64	deg^-2	Inverse variance of RA (no cosine term!), excluding astrometric calibration errors
DEC_IVAR	float64	deg^-2	Inverse variance of DEC, excluding astrometric calibration errors
MAG	float64		Gaia “G” magnitude
MORPHTYPE	int64		Imaging Surveys morphological type from Tractor
GUIDE_FLAG	int64		Should be 1
ETC_FLAG	int64		Should be 0

HDU2

EXTNAME = PMGWCS

Table of WCS coefficients for each GFA.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	72	int	width of table in bytes
NAXIS2	7	int	number of rows in table
EXPID	182039	int
MODULE	GUIDERWCS	str
CHECKSUM	CaGaCW9WCaEaCU9W	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	2237461692	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
GFA_LOC	int64		Location on focal plane of GFA (same numbering convention as petal location)
CRVAL1	float64		WCS keyword and value
CRVAL2	float64		WCS keyword and value
CRPIX1	float64		WCS keyword and value
CRPIX2	float64		WCS keyword and value
CD1_1	float64		WCS keyword and value
CD1_2	float64		WCS keyword and value
CD2_1	float64		WCS keyword and value
CD2_2	float64		WCS keyword and value

HDU3

EXTNAME = PMFIDPOS

Table of predicted FVC CCD pixel coordinates for illuminated fiducials in an FVC image of the focal plane. These are the average of 4 pinhole positions.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	40	int	width of table in bytes
NAXIS2	113	int	number of rows in table
EXPID	182039	int
MODULE	FIDUCIALPOS	str
CHECKSUM	gPHJiPEGgPEGgPEG	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	2559088998	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
PETAL_LOC	int64		Petal location [0-9]
DEVICE_LOC	int64		Device location on focal plane [0-523]
XPIX	float64		CCD X (column) coordinate
YPIX	float64		CCD Y (row) coordinate
FLAGS	int64		Flags as defined somewhere

HDU4

EXTNAME = PMPOSPOS

Table of predicted FVC CCD pixel coordinates for back-illuminated positioner fibers in an FVC image of the focal plane.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	75	int	width of table in bytes
NAXIS2	5020	int	number of rows in table
EXPID	182039	int
MODULE	POSITIONERPOS	str
CHECKSUM	QioaRglUQglaQglU	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	2541629356	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
PETAL_LOC	int64		Petal location [0-9]
DEVICE_LOC	int64		Device location on focal plane [0-523]
DEVICE_TYPE	char[3]		Device type
XFPA	float64	mm	Focal plane CS5 X coordinate
YFPA	float64	mm	Focal plane CS5 Y coordinate
Q	float64	rad	Focal plane CS5 Q coordinate (position angle)
S	float64	mm	Focal plane CS5 S coordinates (radius)
XPIX	float64		CCD X (column) coordinate
YPIX	float64		CCD Y (row) coordinate
FLAGS	int64		Flags as defined somewhere

HDU5

EXTNAME = PMCNTPOS

Table of predicted FVC pixel coordinates for the location of the center-of-travel for positioners in an FVC image of the focal plane.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	40	int	width of table in bytes
NAXIS2	5133	int	number of rows in table
EXPID	182039	int
MODULE	CENTERPOS	str
CHECKSUM	ooVAolUAolUAolUA	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	1382328634	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
PETAL_LOC	int64		Petal location [0-9]
DEVICE_LOC	int64		Device location on focal plane [0-523]
XPIX	float64		CCD X (column) coordinate
YPIX	float64		CCD Y (column) coordinate
FLAGS	int64		Flags as defined somewhere

HDU6

EXTNAME = PMFIBMAP

Table of all target and sky monitor positions after calibration with the FVC.

NOTE: For targets with a non-zero proper motion, FIBER_RA and FIBER_DEC refer to the position at the reference epoch.

Required Header Keywords

Required Header Keywords Table

KEY	Example Value	Type	Comment
NAXIS1	94	int	width of table in bytes
NAXIS2	5020	int	number of rows in table
EXPID	182039	int
MODULE	FIBERMAP	str
CHECKSUM	OQIDPOI9OOIAOOI9	str	HDU checksum updated 2023-05-25T08:35:47
DATASUM	2870350002	str	data unit checksum updated 2023-05-25T08:35:47

Required Data Table Columns

Name	Type	Units	Description
FIBER_RA	float64	deg	RA of actual fiber position
FIBER_DEC	float64	deg	DEC of actual fiber position
FIBER_XI	float64	deg	Actual ICRS tangent plane xi coordinates pointed to by a fiber
FIBER_ETA	float64	deg	Actual ICRS tangent plane eta coordinates pointed to by a fiber
FIBER_RA_IVAR	float32	arcsec^-2	Inverse variance (not meaningful)
FIBER_DEC_IVAR	float32	arcsec^-2	Inverse variance (not meaningful)
FIBER_X	float64	mm	CS5 X location requested by PlateMaker
FIBER_Y	float64	mm	CS5 Y location requested by PlateMaker
DELTA_XFPA	float32	mm	Focal plane X correction (target minus actual)
DELTA_YFPA	float32	mm	Focal plane Y correction (target minus actual)
DELTA_XFPA_IVAR	float32	mm^-2	Inverse variance (not meaningful)
DELTA_YFPA_IVAR	float32	mm^-2	Inverse variance (not meaningful)
LOCATION	int32		Location on the focal plane PETAL_LOC*1000 + DEVICE_LOC
FIBERSTATUS	int32		Fiber status mask. 0=good
DEVICE_LOC	int32		Device location on focal plane [0-523]
NUM_ITER	int32		Number of positioner iterations
SPECTROID	int32		Hardware ID of spectrograph (not used)
PETAL_LOC	int16		Petal location [0-9]

Notes and Examples

There is an inaccuracy in the way proper motions are applied in fields at high dec: the proper motions are applied after target positions have been converted to tangent plane coordinates centered on the field center, but are not corrected to account for the fact that lines of constant RA and DEC are not Cartesian coordinates in the tangent plane.

For targets with a non-zero proper motion, FIBER_RA and FIBER_DEC refer to the position at the reference epoch (but note that the proper-motion correction has been applied at the time of the observation, it is just not recorded in FIBER_RA and FIBER_DEC).