CanariCam fits keywords dictionary
| Name | Value | Description | Units | Additional 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. |