CanariCam fits keywords dictionary

Name ValueDescriptionUnitsAdditional Description
AIRMASS 1.094990 Average airmass for the obs. N/A Average airmass for the observation.
ALARM_1 'none' Obs. event alarm N/A Observation event alarm.
ALARM_2 'none' DC alarm N/A Alarms related with the detector controller.
ALARM_3 'none' DAS alarm N/A Alarms related with the Data Acquisition System.
AM1 1.094870 Effective mean airmass at start N/A Effective mean airmass at start of observation.
AM2 1.095110 Effective mean airmass at end N/A Effective mean airmass at end of observation.
AMEND 1.095113 Airmass at end of obs. N/A Airmass at end of observation.
AMSTART 1.094868 Airmass at start of obs. N/A Airmass at start of observation.
ANGROT 0.000000 Polarimetry reference angle Degrees Position angle of the HWP on the sky (degrees).
APERTURE 'Field1' APERTURE (E) @ Field1 N/A Position of the Aperture wheel
ARCHID 191446 N/A File archive number
ARRAY 'Raytheon_774' name of detector array & MUX N/A Name of the detector array and multiplexer.
AZIMUTH1 -167.698000 Azimuth of observation (degrees) at start Degrees Azimuth in degrees at start of observation.
AZIMUTH2 -167.298000 Azimuth of observation (degrees) at end Degrees Azimuth in degrees at end of observation.
BIASLEVL 'High' V_detgr v bias preset Level: off/Low/Med/Hi N/A Detector bias pre-set level.
BIASPOWR 'ON' Power state of all det. bias voltages: ON/OFF N/A Power state of all detector bias voltages (ON/OFF).
BIASVDAC 0 DAC control value for bias V_detgrv N/A "8-bit value sent to the DAC on bias board to create the actual voltage for V_detgrv, which is commonly called ""the"" Bias Level."
BITPIX 32 Bits per pixel N/A Bits per pixel. This value is 32 in the case of CanariCam.
BSCALE 1 Default scaling factor N/A Scale factor applied to data values.
BUNIT 'ADU' data units are Analog to Digital convert Units N/A Data units are Analog to Digital converter Units.
BZERO 32768 Offset data range to that of unsigned short N/A Offset applied to data values to avoid negative numbers.
CAMMODE 'Imaging' mode of camera (imaging, spectroscopy, etc.) N/A Camera mode (Imaging. Spectroscopy, Polarimetry, Coronography and TEST).
CAT-DEC '+87:10:1.738' DEC from catalogue DD:MM:SS.SSS Declination of object from the catalogue in sexagesimal degrees.
CAT-EPOC 2012.220000 Epoch of proper motion from catalogue years Epoch of proper motion from the catalogue in years.
CAT-EQUI 2000 Equinnox from catalogue years Equinox of catalogue coordinates.
CAT-NAME 'HD126927' Catalog object name N/A Catalogue object name.
CAT-RA '+23:32:4.496' RA from catalogue HH:MM:SS.SSS Right Ascension of object from the catatalogue in sexagesimal degrees.
CCMAXAVG 15785 obs. max. chan. avg. column clamp ADUs ADU Column clamp maximum over all frames in an observation of the average value over 16 channels in each frame. In all min/max calculations of channels, the first 3 small/large outlier pixels in each channel are ignored. The column clamp is one of the samples used to readout the detector. The number of samples used to read the detector depends on the readout mode.
CCMAXMAX 16514 obs. max. chan. max. column clamp ADUs ADU Column clamp maximum over all frames in an observation of the maximum value over 16 channels in each frame.
CCMINAVG 15782 obs. min. chan. avg. column clamp ADUs ADU Column clamp minimum over all frames in an observation of the average value over 16 channels in each frame.
CCMINMIN 14748 obs. min. chan. min. column clamp ADUs ADU Column clamp minimum over all frames in an observation of the minimum value over 16 channels in each frame.
CD1_1 2.216670e-05 WCS matrix element 1,1 Degrees/pixel World coordinate system matrix element 1,1. Its absolute value is the pixel scale in degrees.
CD1_2 -4.290940e-10 WCS matrix element 1,2 Degrees/pixel World coordinate system matrix element 1,2.
CD2_1 4.290940e-10 WCS matrix element 2,1 Degrees/pixel World coordinate system matrix element 2,1.
CD2_2 2.216670e-05 WCS matrix element 2,2 Degrees/pixel World coordinate system matrix element 2,2. Its absolute value is the pixel scale in degrees.
CENTWAVE -1.000000 (um) central wavelength of high res. grating Micron Central wavelength in the case of high resolution spectroscopy (micron). For any mode different to high resolution spectroscopy the keyword takes the value -1.
CHOPFREQ 2.135371 Chop frequency (Hz) Hertz Chop frequency in Hertz.
CHPBEAMS 2 number of chop beams N/A Number of chop beams. This refers to the number of positions that M2 has during chopping. This value is 2 (on-source and off-source) in the case of chop and chop-nod observations.
CHPCOADD 13 # of coadded chop cycles per saveset N/A Number of co-added chop cycles in a saveset. This is the number of on-source/off-source pairs that that co-added in a saveset. For instance, a CHPCOADD of 12, indicates that each saveset is composed of 12 on-source and 12 off-source beams.
CHPDELAY 66.900400 Chop settle time (ms) Milliseconds This value is is an integer multiple of FRMTIME, in milliseconds. The frames taken CHPDELAY milliseconds after M2 starts moving from one beam to the other during chopping are not co-added in the final image.
CHPFREQ 2.135371 Chop frequency (Hz) Hertz Chop frequency in Hertz.
CHPPA -180.000000 M2 Chop position angle (degrees) Degrees Chop position angle on the sky with respect to North. Angles are in the interval [-180, 180] degrees and are positive North to East.
CHPPRFA1 0.000000 Angle w.r.t North of point 1 (degrees) Degrees The chopping is defined internally as two points in the sky in polar coordinates. Angles to define such points are measured in degrees from the North in the interval [-180, 180], being positive to the East. The keyword CHPPRFA1 represents the angle defining the position angle of the first nodding beam.
CHPPRFA2 45.000000 Angle w.r.t North of point 2 (degrees) Degrees The chopping is defined internally as two points in the sky in polar coordinates. Angles to define such points are measured in degrees from the North in the interval [-180, 180], being positive to the East. The keyword CHPPRFA2 represents the angle defining the position angle of the second chopping beam.
CHPPRFD1 0.000000 Chop distance of point 1 (arcsec) Arcseconds The chopping is defined internally as two points in the sky in polar coordinates. The keyword CHPPRFD1 represents the distance modulus in arcseconds from the pointing origin to the first nodding beam.
CHPPRFD2 10.000000 Chop distance of point 2 (arcsec) Arcseconds The chopping is defined internally as two points in the sky in polar coordinates. The keyword CHPPRFD2 represents the distance modulus in arcseconds from the pointing origin to the second chopping beam.
CHPSETTL 2 # frames discarded during chop settle time N/A Number of frames discarded due to settling of the chopper when M2 moves from one chopping beam to the other.
CHPTHROW 10.000000 M2 Chop throw (arcsec) Arcseconds Chop throw in arcseconds.
CLAMPAVG 15785 avg. column clamp ADUs in last frame ADU Average over the 16 channels of the column clamp value for the current (any extension) or last (primary extension) frame.
CLAMPMAX 16514 max. column clamp ADUs in last frame ADU Maximum over the 16 channels of the column clamp value for the current (any extension) or last (primary extension) frame.
CLAMPMIN 14755 min. column clamp ADUs in last frame ADU Minimum over the 16 channels of the column clamp value for the current (any extension) or last (primary extension) frame.
COLDFING '+08.494' Kelvin (cold finger array mount) Kelvin Temperature of the cold finger array mount.
COLDHED1 '+06.817' Kelvin: Cold Head 1st Stage Kelvin Temperature of the cold head first stage.
COLDHED2 '+31.107' Kelvin: Cold Head 2nd Stage Kelvin Temperature of the cold head second stage.
COLDPLAC '+11.083' Kelvin: Cold Plate Center Kelvin Temperature of the cold plate center.
COLDPLAT '+09.559' Kelvin: Cold Plate in Dark Box Kelvin Temperature of the cold plate in dark box.
COMMENT This is a comment None N/A Keyword used to include comments of whatever nature
COMPSTAT 'COMPLETE' Observation completion status N/A Observation completion status.
CRPIX1 462.5 Ref pix of axis 1 Pixels Pixel in image corresponding to the RA given by CRVAL1
CRPIX1 155.200000 Coordinate system reference pixel Pixels X coordinate of reference pixel in the detector for WCS transformation. The Right Ascension on the sky corresponding to this pixel is given in the keyword CRVAL1.
CRPIX2 995.23 Ref pix of axis 2 Pixels Pixel in image corresponding to the DEC given by CRVAL2
CRPIX2 129.900000 Coordinate system reference pixel Pixels Y coordinate of reference pixel in the detector for WCS transformation. The Declination on the sky corresponding to this pixel is given in the keyword CRVAL2.
CRVAL1 1.55213538050385 RA at Ref pix in decimal degrees Degrees This is the Right ascension of the pixel given in CRPIX1
CRVAL1 167.415920 Coordinate system value at reference pixel Degrees Right Ascension corresponding to the reference pixel X coordinate CRPIX1.
CRVAL2 63.6936537290756 DEC at Ref pix in decimal degrees Degrees This is the declination of the pixel given in CRPIX2
CRVAL2 44.498499 Coordinate system value at reference pixel Degrees Declination corresponding to the reference pixel Y coordinate CRPIX2.
CTYPE1 'RA---TAN' CTYPE1 N/A System used for world coordinate projection. Must be written exactly as 'RA---TAN'.
CTYPE2 'DEC--TAN' CTYPE2 N/A System used for world coordinate projection. Must be written exactly as 'RA---TAN'.
CYCLETYP 14 Cycle Type for obs. mode. N/A Internal number in the CanariCam electronics to define the type of cycle for observing mode.
DARKBOXW '+10.498' Kelvin: Dark Box Wall Kelvin Temperature of the dark box wall.
DARKTIME 1.404908 Time from start to readouts (sec) Seconds Time in seconds from the start of observation until commencement of readouts.
DATAMODE 'SAVE' Disposition of data (i.e. save/discard) N/A Disposition of data (SAVE/DISCARD).
DATE '2012-03-20' Date FITS file was generated N/A Time stamp for fits file creation. This is not the time of observation.
DATE_FH '2012:079:11:37:04' UT of header creation (YYYY:DAY:HH:MM:SS) N/A Time of FITS header creation.
DATE-OBS '2012-03-20' Date of start of observation N/A Date at the start of the observation.
DEC 44.498506 DEC of the instrument scientific aperture Degrees Declination the telescope is aiming to in decimal degrees.
DETARRAY '+08.899' Kelvin (diode on detector array carrier) Kelvin Detector temperature.
DHSLABEL 'Test' DHS Label (=DHS data file name) String Inherited from GEMINI (neglect)
DOME_AZ 192.379000 Dome azimuth (degrees) Degrees Azimuth of the Dome aperture.
DOME_EL 90 Upper shutter elevation (degrees) Degrees Upper shutter elevation.
DTEMPCON 0.000000 Status of Det. Temp. control: 1=on, 0=off N/A Status of the detector temperature control (0=OFF, 1=ON)
DTEMPSET 9.500000 Det. Temp. control set point (Kelvin) Kelvin Set point of the detector temperature control.
EFF_CHP 82.352941 Chop duty cycle (%) Percent Chopping efficiency. This value indicates the percentage of time that CanariCam is actually integrating while chopping. Note that CanariCam does not accumulate frames into the final image when M2 is moving from one chop beam to the other. It only accumulates frames once M2 is already settled in one the the chop beams.
EFF_FRM 100.000000 Frame duty cycle (%) Percent This is always 100%, since
EFF_NOD 89.521610 Nod duty cycle (%) Percent Nodding efficiency. This value indicates the percentage of time that CanariCam is actually integrating while nodding. Note that CanariCam does not accumulate frames into the final image when the telescope axes are nodding between two nod beams.
EFF_SRC 36.861839 Source photons duty cycle (%) Percent Percentage on-source photons are collected during an observation.
ELAPSED 1633.392736 Elapsed time (seconds) Seconds Total observation time, including all chopping and nodding overheads. Does not include the time required for telescope pointing, pre-setting and instrument setting. It is the same as TOTALTIME, but expressed in seconds instead of minutes.
END End of FITS header N/A Marks end of image header
EPS 1.000000 Polarimetry analyser efficiency N/A Efficiency factor for the analyser in polarimetry mode. This keyword is normally needed for the Starlink/POLPACK polarimetry data reduction software. In the case of dual-beam polarimetry, used by CanariCam, is set to 1.
EQUINOX 2000 EQUINOX Year Equinox of observation.
EXPOSED 23.0478 Exposure time including pauses (sec) Seconds Exposure time on-source in seconds.
EXPTIME 13.045578 Exposure time excluding pauses (sec) Seconds Exposure time on-source in seconds.
EXTEND T FITS dataset contains extensions. N/A Mark end of fits header extension.
EXTEND T May the FITS file contain extensions? N/A Indicates in the primary extension if the file contains more than one extension (T=TRUE, F=FALSE).
EXTNAME 'CCD_1_L1_1' Extension Name N/A Extension name according to detector been read, readout mode, and readout channel.
EXTNAME 'Beam A of NodSet 1' Name of the extension N/A Name of the FITS extension.
EXTVER 1 Version of the extension N/A "To be used to distinguish among different extensions in a FITS file with the same type and name, i.e., the same values for XTENSION and EXTNAME."
FILEDIR '/data/CanariCam/2012-07 file path on LCU disk N/A Directory where the FITS file is initially stored in the CanariCam Local Control Unit (internal use only).
FILENAME 'CC2012-079-006_acc.fits Data file on LCU disk N/A Name of the FITS file is initially stored in the CanariCam Local Control Unit (internal use only).
FILSTAT 'COMMITED' N/A File status??
FILTER1 'ArIII-8.99' FILTER1 (H) @ ArIII-8.99 N/A Position of filter wheel 1.
FILTER2 'Open' FILTER2 (I) @ Open N/A Position of filter wheel 2.
FRAME 'FK5' Target coordinate system N/A Target coordinate system.
FRMCOAD1 4 # frames coadded - 1 (for MCE cycle types) N/A Number of single frames (frames of exposure time FRMTIME) minus one, co-added in a chop cycle.
FRMCOAD2 3 # frames coadded - 2 (for MCE cycle types) N/A Number of single frames (frames of exposure time FRMTIME) co-added minus two, in a chop cycle.
FRMCOADD 5 # frames coadded per chop cycle N/A Number of single frames (frames of exposure time FRMTIME) co-added in a chop cycle.
FRMSPROC 12 # of frames processed (accumulated) N/A Total number of savesets in the accumulated signal image. This is the product of the number of savesets per extension multiplied by the number of extensions and multiplied by the number of chop beams.
FRMTIME 33.450200 Frame readout time (ms) Milliseconds Minimum integration (in milliseconds) time for an observation. All other times defined in a CanariCam observation are integer multiples of the frame time. The frame time is automatically selected by the CanariCam control software, depending on filter and background emission conditions to prevent saturation of the detector.
FSTATION 'NASMYTH-A' Focal station of observation N/A GTC focal station of observation.
GAIN 120.000000 Electrons per ADU Electrons/ADU Conversion factor between electrons and Analog Digital Units.
GRATING 'Mirror' GRATING (L) @ Mirror N/A Position of grating turret.
GRATMOTO '+53.604' Kelvin: Grating Turret Motor Kelvin Temperature of the grating turret motor.
GTCOBID '0000' Observing block ID N/A Observing block number.
GTCPRGID 'CIS-TIS_TEST' Proposal code N/A Unique observing program ID.
HEIGHT 2348 Height above sea level (m) Meter Telescope altitude above sea level in meters.
HUMIN1 30.800000 Indoor relative humidity at start Percent Indoor relative humidity at start of observation.
HUMIN2 30.900000 Indoor relative humidity at end Percent Indoor relative humidity at end of observation.
HUMOUT1 24.900000 Outdoor relative humidity at start Percent Outdoor relative humidity at start of observation.
HUMOUT2 24.500000 Outdoor relative humidity at end Percent Outdoor relative humidity at end of observation.
HWP 'Open' HWP (C) @ win_image N/A Half-Wave-Plate wheel position. In polarimetry mode this wheel should be in the 'hwp_10um' position. In the remaining modes it should be in the 'Open' position.
INDEXR-A -1 steps from Datum of indexor A (Sector Wheel) Indexer units Sector wheel motor indexer steps from datum.
INDEXR-B 2340 steps from Datum of indexor B (Window Changer) Indexer units Window changer motor indexer steps from datum.
INDEXR-C 644 steps from Datum of indexor C (Hwp Wheel) Indexer units Half-Wave-Plate wheel motor indexer steps from datum.
INDEXR-D 0 steps from Datum of indexor D (WPlate Angle) Indexer units Wave-Plate angle motor indexer steps from datum.
INDEXR-E 71 steps from Datum of indexor E (Aperture Wheel) Indexer units Aperture wheel motor indexer steps from datum.
INDEXR-F 88 steps from Datum of indexor F (Lyot Wheel) Indexer units Lyot wheel motor indexer steps from datum.
INDEXR-G 0 steps from Datum of indexor G (Mask-Rotator) Indexer units Field mask-rotator wheel motor indexer steps from datum.
INDEXR-H 11 steps from Datum of indexor H (Filter1 Wheel) Indexer units Filter 1 wheel motor indexer steps from datum.
INDEXR-I 1065 steps from Datum of indexor I (Filter2 Wheel) Indexer units Filter 2 wheel motor indexer steps from datum.
INDEXR-J 785 steps from Datum of indexor J (Slit Wheel) Indexer units Slit wheel motor indexer steps from datum.
INDEXR-K 17 steps from Datum of indexor K (Prism Slide) Indexer units Wollaston prism slide motor indexer steps from datum.
INDEXR-L -2616 steps from Datum of indexor L (Grating Turret) Indexer units Grating turret wheel motor indexer steps from datum.
INSTRAA 0.000000 Instrument alignment (degrees) Degrees Alignment of the instrument in the telescope focal plane.
INSTRPA 0.000000 Instrument position angle (degrees) Degrees Position angle of the instrument on the sky. Angles are measured in degrees from the North and are positive when the instrument vertical axis is to the East of North.
INSTRUME 'CanariCam' Name of instrument acquiring data N/A Name of the instrument.
JD 2456006.983843 Julian date midtime of observation Days Julian date at observation mid-time
LATITUDE 28.762000 Telescope latitude (degrees), +28:45:43.2 Degrees Telescope geographical latitude.
LATITUDE 28762000 Telescope latitude (degrees), +28:45:43.2 Degrees Telescope latitude
LCU_NAME 'ormlcu33' hostname of LCU N/A Hostname of the CanariCam Local Control Unit (internal use only).
LONGITUD 17.877639 Telescope longitude (degrees), +17:52:39.5 Degrees Telescope geographical longitude.
LYOT 'Circ1' LYOT (F) @ Circ1 N/A Position of the Lyot wheel.
LYOTMOTO '+46.434' Kelvin: Lyot Wheel Motor Kelvin Temperature of the Lyot wheel.
M2CEBAFL 'OPENED' M2 central baffle N/A Position of the M2 central baffle (OPENED/CLOSED/UNDEF). This baffle must be in the 'OPENED' position for CanariCam observations to minimize the its thermal emission.
M2EXFLAP 'RETRACTED' M2 external flaps N/A Position of the M2 internal flaps (DEPLOYED/RETRACTED/UNDEF). This baffle must be in the 'RETRACTED' position for CanariCam observations to minimize the its thermal emission.
M2INFLAP 'RETRACTED' M2 internal flaps N/A Position of the M2 external flaps (DEPLOYED/RETRACTED/UNDEF). This baffle must be in the 'RETRACTED' position for CanariCam observations to minimize the its thermal emission.
MASK-ROT 0.000000 (degrees) angle of Lyot mask Degrees Rotator angle of the Lyot mask. This value can be non-zero when a non-circular mask is in the optical path, e.g. when the Lyot wheel is in the positions 'ROSE_PETAL' or 'PIE_WEDGE'.
MCE_BIAS 3 MCE Bias Level: 0=off, 1=Low, 2=Med, 3=High N/A Bias level of the CanariCam electronics (Modular Camera Electronics - MCE).
MCE_SIM 0 MCE sim mode (0=no sim, normal obs.) N/A Simulator mode of Modular Camera Electronics. For normal science observations this keyword should take a value 0.
MCE_WELL 0 MCE Well Depth setting: 0=shallow, 1=deep N/A Detector well depth setting in the Modular Camera Electronics.
META_AM 1.500000 META-config: input Airmass N/A Input airmass for instrument setup calculation.
META_AT 0.000000 META-config: input Temperature (C) Celsius Input atmospheric water vapor content for instrument setup calculation.
META_FT 34.000000 Meta-config: estimated Frame Time (ms) Milliseconds Input estimated frametime value.
META_TE 0.000000 META-config: input emissivity N/A Input telescope emissivity for instrument setup.
META_WV 3.000000 META-config: input Water Vapour (mm) Millimetres Input atmospheric water vapor content for instrument setup.
MJD-OBS 56006.483843 Modified Julian date midtime of observation Days Modified Julian date at observation midtime.
NAXIS 4 N/A Number of data axes. This value is 2 for all CanariCam accumulated-signal images, 3 for for CanariCam polarimetry data and 4 for CanariCam imaging, spectroscopy and coronography data.
NAXIS1 320 X dimension of array N/A Number of data pixels in axis 1. In CanariCam this corresponds to the detector size in the X direction.
NAXIS2 240 Y dimension of array N/A Number of data pixels in axis 2. In CanariCam this corresponds to the detector size in the Y direction.
NCHOPS 2 # of chop positions (NAXIS3) N/A Number of chop positions. This value is 2 when OBSMODE is 'chop', 'chop-nod' and 'chop-nod-pol'. The keyword value is 1 when OBSMODE is 'stare' and 'nod'.
NNODS 2 # of nod beam positions (NAXIS5) N/A Number of nod beam positions. The same as NODBEAMS. This value is 2 when OBSMODE is 'nod', 'chop-nod' and 'chop-nod-pol'. The keyword value is 1 when OBSMODE is 'stare' and 'chop'.
NNODSETS 4 # of nod cycles (NAXIS6) N/A Number of nod cycles, i.e. number of nod pairs A-B (or B-A).
NOD 'A' Name of Nod Phase (A or B). N/A Name of nod beam (A or B).
NODBEAMS 2 number of nod beams N/A Number of nod beam positions. The same as NNODS. This value is 2 when OBSMODE is 'nod', 'chop-nod' and 'chop-nod-pol'. The keyword value is 1 when OBSMODE is 'stare' and 'chop'.
NODDELAV 8.714286 average time for nod beam switches (sec) Seconds Average time for nod beam switches.
NODDELAY 9.000000 approx. occuring nod settle time (sec) Seconds Approximately time for not beam switches.
NODMODE 'parallel' Nod mode (parallel/perpendicular) N/A Indicates whether nodding is parallel or perpendicular to chopping.
NODPA -0.000000 Nod position angle (degrees) Degrees Nod position angle on the sky with respect to North. Angles are in the interval [-180, 180] degrees and are positive North to East.
NODPATRN 'A-BB-A' nod beam switch pattern: A-B-A-B or A-BB-A N/A Nod pattern definition. It can take the values A-BB-A or A-B-A-B.
NODPRFA1 0.000000 Angle w.r.t North of point 1 (degrees) Degrees The nodding is defined internally as two points in the sky in polar coordinates. Angles to define such points are measured in degrees from the North in the interval [-180, 180], being positive to the East. The keyword NODPRFA1 represents the angle defining the position angle of the first nodding beam.
NODPRFA2 -135.000000 Angle w.r.t North of point 2 (degrees) Degrees The nodding is defined internally as two points in the sky in polar coordinates. Angles to define such points are measured in degrees from the North in the interval [-180, 180], being positive to the East. The keyword NODPRFA2 represents the angle defining the position angle of the second nodding beam.
NODPRFD1 0.000000 Nod distance of point 1 (arcsec) Arcseconds The nodding is defined internally as two points in the sky in polar coordinates. The keyword NODPRFD1 represents the distance modulus in arcseconds from the pointing origin to the first nodding beam.
NODPRFD2 10.000000 Nod distance of point 2 (arcsec) Arcseconds The nodding is defined internally as two points in the sky in polar coordinates. The keyword NODPRFD2 represents the distance modulus in arcseconds from the pointing origin to the second nodding beam.
NODSET 1 Index of NodSet. N/A Nodset index for each extension. Each pair of A-B (or B-A) nods is identified with a sequential number. Hence, the NODSET value will be increased by 1 every two extensions if OBSMODE is 'chop-nod' or 'nod'. If OBSMODE is 'chop-nod-pol', the NODSET value will be increased by 1 every eight extensions, since in polarimetry a nod beam switch occurs every four extensions, each group of four extensions corresponding to a set of half-wave plate angles (0.0, 45.0, 22.5 and 67.5 degrees).
NODSETS 1 # of nod cycles per total integration N/A Number of nod sets. The same as NNODSETS.
NODSETTL 0 (not used) # chop cycles discarded during nod s N/A Number of chop cycles discarded during a nod set. This keyword is NOT USED and its value is always 0.
NODSETTR 0 (not used) # frames discarded during nod settle N/A Number of frames discarded during nod settling. This keyword is NOT USED and its value is always 0.
NODTHROW 10.000000 Nod throw (arcsec) Arcseconds Chop throw in arcseconds.
NODTIME 45.506208 Nod time (sec) in each nod beam Seconds Time the telescope spends in each nod beam.
NODTYPE 'radec' Nod Type N/A Type of nodding. This can be defined based on the celestial coordinate system or any other coordinate system, e.g. telescope pupil coordinates.
NPANGNOD 4 Polarim: number of HWP angles per Nod Beam N/A Number of half-wave plate angles per nod beam in the case of polarimetry observations. This keyword is only defined in polarimetry observations and its value is always 4, corresponding to the set of HWP angles 0.0, 45.0, 22.5 and 47.5 degrees.
NSAVSETS 8 # of savesets per nod beam (NAXIS4) N/A Number of savesets per nod beam. In a complete observation this keyword has the same value as NAXIS4 and SAVESETS.
OBJECT 'Cygnus_A' Object name N/A User defined target name.
OBJTIME 582.479462 On-source time (seconds) Seconds Actual time on-source without any overheads.
OBSCLASS 'SCIENCE' Observation class N/A Observation class ('SCIENCE', 'CALIB', ' ACQ', etc)
OBSERVAT 'ORM' Name of observatory (IRAF style) N/A Name of the observatory.
OBSERVER 'SA' Observer ID N/A Observer name (SA = support astronomer).
OBSMODE 'chop-nod' Observing mode (chop, nod, stare, chop-nod) N/A Instrument observing mode ('stare', 'chop', 'nod', 'chop-nod', 'chop-nod-pol').
OBSTYPE 'POLAR' Observation type N/A Observation type ('POLAR', 'STD'. 'SKY', etc)
OCLMPAVG 0 average ADUs output clamp in last frame ADU Average over the 16 channels of the output clamp value for the current (any extension) or last (primary extension) frame. In all min/max calculations of channels, the first 3 small/large outlier pixels in each channel are ignored. The output clamp is one of the samples used to readout the detector. The number of samples used to read the detector depends on the readout mode.
OCLMPMAX 0 maximum ADUs output clamp in last frame ADU Maximum over the 16 channels of the output clamp value for the current (any extension) or last (primary extension) frame.
OCLMPMIN 0 minimum ADUs output clamp in last frame ADU Minimum over the 16 channels of the output clamp value for the current (any extension) or last (primary extension) frame.
OCMAXAVG 0 obs. max. chan. avg. output clamp ADUs ADU Output clamp maximum over all frames in an observation of the average value over 16 channels in each frame.
OCMAXMAX 0 obs. max. chan. max. output clamp ADUs ADU Output clamp maximum over all frames in an observation of the maximum value over 16 channels in each frame.
OCMINAVG 0 obs. min. chan. avg. output clamp ADUs ADU Output clamp maximum over all frames in an observation of the average value over 16 channels in each frame.
OCMINMIN 0 obs. min. chan. min. output clamp ADUs ADU Output clamp minimum over all frames in an observation of the minimum value over 16 channels in each frame.
ORIGIN 'ORM-LAPALMA' FITS file originator N/A FITS file originator.
PARALLAX 0 Parallax from catalog (arcsec) Arcseconds Target parallax from catalogue in arcseconds.
PARANG1 9.929800 Parallactic angle (degrees) at start Degrees Parallactic angle at start of observation.
PARANG2 10.278700 Parallactic angle (degrees) at end Degrees Parallactic angle at end of observation.
PASVSHLD '+231.48' Kelvin: Passive Shield Kelvin Temperature of the passive shield.
PI 'Galileo Galilei' Proposal principal investigator N/A Principal investigator of the project for which the observation was taken.
PIXCLOCK 7 MCE Pixel Base Clock (PBC) N/A Modular Camera Electronics Pixel Base Clock.
PLATESCA 0.080000 Plate scale ( arcsec/pixel ) Arcseconds Detector plate scale in arcseconds per pixel.
PM-DEC 0 Proper motion in DEC from catalogue (arcsec/yr) Arcseconds/Year Target declination proper motion in arcseconds per year.
PM-RA 0 Proper motion in RA from catalogue (arcsec/yr) Arcseconds/Year Target right-ascension proper motion in arcseconds per year.
POSTCHPS 3 # of post-valid discarded chop cycles N/A Number of chop cycles discarded after the end of the observation.
POSTCHPT 1.034232 Time (sec) after valid chopping is done. Seconds Time discarded after the end of the observation.
POX 0 Pointing Origin x coordinate (mm) Millimetres Pointing origin X coordinate in the telescope focal plane.
POY 0 Pointing Origin y coordinate (mm) Millimetres Pointing origin Y coordinate in the telescope focal plane.
PRECHPS 3 # of pre-valid discarded chop cycles N/A Number of chop cycles discarded before the start of the observation.
PRECHPT 1.034232 Time from start until valid data (sec) Seconds Time discarded before the start of the observation.
PRESSURE ' 3.4900E-08' Torr Torr Internal pressure in the CanariCam dewar.
PRISM 'Open' PRISM (K) @ Open N/A Position of the Wollaston prism slide. It should be 'Open' for all modes exept for Polarimetry, where should take the value 'Prism'.
PUPILANG 1.972209 Pupil Angle (radians) for Coron. mode Radians Pupil angle in radians. This keyword only appears in coronography mode.
PWVMON1 6.700000 PWV monitor measurement (mm) at start Millimetres Atmospheric water vapour content measured in terms of millimetres of Precipitable Water Vapour by a PWV monitor. The information that feeds this keyword is extracted from the GPS-based PWV monitor operated by the IAC. The value recorded in this keyword is not exactlty the same as the PWV value the observer was receiving at the time of the observation, because the monitor does not record the instantaneous PWV value. It corrects all previous values of the PWV once a new one is generated. The corrected value is the one that is recorded in the FITS keyword.
PWVMON2 7.400000 PWV monitor measurement (mm) at end Millimetres Atmospheric water vapour content measured in terms of millimetres of Precipitable Water Vapour by a PWV monitor. The PWV monitor based on the GPS technique is used for this observation. The same comment as for PWVMON1 regarding the origin of the recorded value applies to this keyword.
RA 330.000080 RA of the instrument scientific aperture HH:MM:SS.SSS Right ascension the telescope is aiming to in decimal degrees.
RADESYS 'FK5' RADESYS N/A Reference system for World Coordinate System.
RADVEL 0 Radial velocity from catalogue (km/sec) km/s Radial velocity of target from catalogue expressed in kilometres per second.
READMODE 'S1R1_CR' Detector Readout mode (single or multi-samples) N/A Detector readout mode.
READNOIS 840.000000 Readout noise st.dev. in electrons per pixel N/A Readout noise standard deviation in electrons per pixel.
ROTATOR1 0 Rotator mechanical angle (degrees) at start Degrees Focal plane de-rotator angle at observation start.
ROTATOR2 0 Rotator mechanical angle (degrees) at end Degrees Focal plane de-rotator angle at observation end.
SAVCOADD 276 # frames coadded each chop beam of save set N/A Number of frames co-added in each chop beam of a saveset. This value corresponds to CHPCOAD*FRMCOADD.
SAVEFREQ 0.164259 Save frequency (Hz) Seconds Frequency at which savesets are generated. It is the inverse of SAVETIME. A saveset is the minimum time interval that can be saved in a CanariCam raw FITS file.
SAVESETS 6 # of savesets from MCE during each nod beam N/A Number of savesets per nod beam. In a complete observation this keyword has the same value as NAXIS4 and NSAVSETS.
SAVETIME 6.087936 Time between Data Save Sets (sec) Seconds Time between data savesets. It is the inverse of SAVEFREQ. A saveset is the minimum time interval that can be saved in a CanariCam raw FITS file.
SCMAXAVG 9.442142 obs. max. chan. avg. column clamp noise st.dev. ADU Maximum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for column clamp differences in time. Sequential readouts of reference frames are taken at save frequency. Since time differences are at save period, the sigmas are larger than readout noise when save period > 1 second, because the saved reference frame differences are also affected by sky fluctuations, which are reduced in data by chopping.
SCMAXMAX 13.485950 obs. max. chan. max. column clamp noise st.dev. ADU Maximum over all frames in an observation of the maximum value over 16 channels in each frame of sigma standard deviation for column clamp differences in time.
SCMINAVG 9.251961 obs. min. chan. avg. column clamp noise st.dev. ADU Minimum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for column clamp differences in time.
SCMINMIN 7.288932 obs. min. chan. min. column clamp noise st.dev. ADU Minimum over all frames in an observation of the minimum value over 16 channels in each frame of sigma standard deviation for column clamp differences in time.
SECTOR 'Open' SECTOR (A) @ Open N/A Position of the Sector wheel.
SEEING -999.000000 Seeing monitor measurement (arcsec) Arcseconds Seeing value in arcseconds measured by a seeing monitor.
SIGCLAMP 9.366573 avg. column clamp noise st.dev. in last frame ADU Average value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for column clamp differences in time. Sequential readouts of reference frames are taken at save frequency. Since time differences are at save period, the sigmas are larger than readout noise when save period > 1 second, because the saved reference frame differences are also affected by sky fluctuations, which are reduced in data by chopping.
SIGCLMAX 13.296366 max. column clamp noise st.dev. in last frame ADU Maximum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for column clamp differences in time.
SIGCLMIN 7.343230 min. column clamp noise st.dev. in last frame ADU Minimum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for column clamp differences in time.
SIGOCLMP 0.000000 avg. output clamp noise st.dev. in last frame ADU Average value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for output clamp differences in time.
SIGOCMAX 0.000000 max. output clamp noise st.dev. in last frame ADU Maximum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for output clamp differences in time.
SIGOCMIN 0.000000 min. output clamp noise st.dev. in last frame ADU Minimum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for output clamp differences in time.
SIGWELL 12.691120 avg. st.dev. of well noise in last frame ADU Average value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for well clamp differences in time.
SIGWMAX 18.380568 max. st.dev. of well noise in last frame ADU Maximum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for well clamp differences in time.
SIGWMIN 6.752966 min. st.dev. of well noise in last frame ADU Minimum value over 16 channels in the current (any extension) or last (primary extension) frame of sigma standard deviation for well clamp differences in time.
SIMPLE T Written by FrameAcqServer.cc,v 2.137 2011/06/25 N/A Whether the file conform to fits standard.
SLATEL 'LP10.0' Telescope name known to SLALIB N/A Telescope name known to SLALIB.
SLIT 'Open' SLIT (J) @ Open N/A Position of the Slit wheel.
SOMAXAVG 0.000000 obs. max. chan. avg. output clamp noise st.dev. ADU Maximum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for output clamp differences in time. Sequential readouts of reference frames are taken at save frequency. Since time differences are at save period, the sigmas are larger than readout noise when save period > 1 second, because the saved reference frame differences are also affected by sky fluctuations, which are reduced in data by chopping.
SOMAXMAX 0.000000 obs. max. chan. max. output clamp noise st.dev. ADU Maximum over all frames in an observation of the maximum value over 16 channels in each frame of sigma standard deviation for output clamp differences in time.
SOMINAVG -1.000000 obs. min. chan. avg. output clamp noise st.dev. ADU Minimum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for output clamp differences in time.
SOMINMIN -1.000000 obs. min. chan. min. output clamp noise st.dev. ADU Maximum over all frames in an observation of the minimum value over 16 channels in each frame of sigma standard deviation for output clamp differences in time.
SOURCTIM 0.217426 On-source time (minutes) Minutes Total on-source time in minutes.
ST1 '22:18:30.091' Local sidereal time at start of observation HH:MM:SS.SSS Local sidereal time at observation start.
ST2 '22:19:10.200' Local sidereal time at end of observation HH:MM:SS.SSS Local sidereal time at observation end.
SWMAXAVG 12.949117 obs. max. chan. avg. st.dev. of well noise ADU Maximum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for well clamp differences in time. Sequential readouts of reference frames are taken at save frequency. Since time differences are at save period, the sigmas are larger than readout noise when save period > 1 second, because the saved reference frame differences are also affected by sky fluctuations, which are reduced in data by chopping.
SWMAXMAX 18.380568 obs. max. chan. max. st.dev. of well noise ADU Maximum over all frames in an observation of the maximum value over 16 channels in each frame of sigma standard deviation for well clamp differences in time.
SWMINAVG 12.691120 obs. min. chan. avg. st.dev. of well noise ADU Minimum over all frames in an observation of the average value over 16 channels in each frame of sigma standard deviation for well clamp differences in time.
SWMINMIN 6.677858 obs. min. chan. min. st.dev. of well noise ADU Maximum over all frames in an observation of the minimum value over 16 channels in each frame of sigma standard deviation for well clamp differences in time.
T 1.000000 Polarimetry transmission N/A Transmission for the analyser in polarimetry mode. This keyword is normally needed for the Starlink/POLPACK polarimetry data reduction software. In the case of dual-beam polarimetry, used by CanariCam, is set to 1.
T_PRIM1 4.750000 Mean M1 temperature (degrees Celsius) at start Celsius Temperature of telescope primary mirror at observation start.
T_PRIM2 4.775000 Mean M1 temperature (degrees Celsius) at end Celsius Temperature of telescope primary mirror at observation end.
T_TUBE1 6.131430 Truss temperature (degrees Celsius) at start Celsius Temperature of telescope truss at observation start.
T_TUBE2 6.145710 Truss temperature (degrees Celsius) at end Celsius Temperature of telescope truss at observation end.
TELESCOP 'GTC ' Telescope id. N/A Telescope name
TELFOCUS 0 Telescope focus (mm) Millimetres Telescope focus in millimetres.
TOTALTIM 27.223212 Elapsed time (minutes) Minutes Total observation time, including all chopping and nodding overheads. Does not include the time required for telescope pointing, pre-setting and instrument setting. It is the same as ELAPSED, but expressed in minutes instead of seconds.
TOTFRMS 12 total # of frames from MCE saved N/A Total number of frames saved in the raw data set. This corresponds to NSAVSETS*NCHOPS*NNODS*NNODSETS.
USERNOTE '' Optional note made by user about obs. N/A Optional comment made by the observer about the observation,
UT1 '11:36:24.1' UTC at start of observation HH:MM:SS.S Universal Coordinated Time at observation start.
UT2 '11:37:04.0' UTC at end of observation HH:MM:SS.S Universal Coordinated Time at observation end.
UTEND '11:37:04.0' UTC at end of observation HH:MM:SS.S Universal Coordinated Time at observation start.
UTSTART '11:36:24.1' UTC at start of observation HH:MM:SS.S Universal Coordinated Time at observation end.
VGATE 'ON' State of det. V_gate bias: ON/OFF N/A State of detector V_gate bias (ON/OFF).
WARNING1 'none' Obs. event warning N/A Warning from the observation event log.
WARNING2 'none' DC warning N/A Warning from the detector controller.
WCSAXES 2 Number of axes in the WCS description N/A evitar warning en keywords WCS en imágenes raw(MEF): http://heasarc.gsfc.nasa.gov/docs/software/ftools/fitsverify/Comentario de la keyword añadido según esl estándar http://fits.gsfc.nasa.gov/standard30/fits_standard30aa.pdf
WELLAVG 17570 average well ADUs in last frame ADU Average well ADUs in the last frame in a given nod position.
WELLDPTH 'shallow' detector well depth: shallow/deep N/A Detector well depth. It can take the values 'shallow' or 'deep'.
WELLMAX 30379 maximum well ADUs in last frame ADU Maximum well ADUs in the last frame in a given nod position.
WELLMIN 12527 mininum well ADUs in last frame ADU Minimum well ADUs in the last frame in a given nod position.
WINDOW 'ZnSe' WINDOW (B) @ Blank_mirror N/A Window changer position..
WLMAXAVG 17570 obs. max. chan. average well ADUs ADU Well clamp maximum over all frames in an observation of the average value over 16 channels in each frame. In all min/max calculations of channels, the first 3 small/large outlier pixels in each channel are ignored. The well clamp is one of the samples used to readout the detector. The number of samples used to read the detector depends on the readout mode.
WLMAXMAX 30380 obs. max. chan. max. well ADUs ADU Well clamp maximum over all frames in an observation of the maximum value over 16 channels in each frame.
WLMINAVG 17568 obs. min. chan. average well ADUs ADU Well clamp minimum over all frames in an observation of the average value over 16 channels in each frame.
WLMINMIN 12520 obs. min. chan. min. well ADUs ADU Well clamp minimum over all frames in an observation of the minimum value over 16 channels in each frame.
WPLATE 0.000000 (degrees) angle of half wave plate Degrees Half-wave plate angle in degrees. In the case of polarimetry observations, the value each extension has a different angle, following the sequence 0.0, 45.0, 22.5 and 67.5. This sequence is repeated as many times as needed until the end of the observation.
XTENSION 1 FITS extension N/A
ZD1 24.051400 Zenith-distance of observation (degrees) at start Degrees Zenith distance of at observation start.
ZD2 24.079600 Zenith-distance of observation (degrees) at end Degrees Zenith distance of at observation end.