OSIRIS fits keywords dictionary
| Name | Value | Description | Units | Additional Description |
|---|
| AG1ARM | 90.375 | ASG arm position | degrees | AG1ARM=90 means the ARM is placed at the center of the focal plane |
| AG1FOCUS | 43.17 | ASG focus position | mm | AG1FOCUS=0 is the correct value at center of focal plane |
| AG1TURNT | 37.123 | ASG turn table position | degrees | Guide probe turn table position. |
| AIRMASS | 1.2 | AIRMASS | N/A | AIRMASS=1 means observation was started at zenith |
| AMPNAME | 'CCD_1: Left' | Name of the amplifier used during readout | N/A | Name of the amplifier used during readout |
| AMPSEC | '[1:2048,1:4102]' | AMP Section | Pixels | Amplifier section in pixels |
| APPLYPRE | 'true ' | Reordering applied or not | N/A | Boolean |
| ARCHID | 175464 | File archive number | N/A | File archive number |
| ASGDEC | '+62:16:21.821' | ASG declination | DD:PP:SS | Useful to know which guide star was used during observation |
| ASGRA | '+12:37:36.550' | ASG right ascension | HH:MM:SS | Useful to know which guide star was used during observation |
| AZIMUTH | 166.983854397316 | Azimuth at start of observation | degrees | Telescope azimuth |
| BIASSEC | '[3:22,5:2051]' | BIAS section | Pixels | Bias section. Area where to measure bias. |
| BITPIX | 16 | Number of bits for data pixel | N/A | This means CCD saturates at 65563 ADU. |
| BSCALE | 1 | Default scaling factor | N/A | Scale factor applied to data values. |
| BZERO | 32768 | Offset data range to that of unsigned short | N/A | Offset applied to data values to avoid negative numbers. |
| CCDSUM | '2 2 ' | First horizontal bin, then vertical bin | N/A | Indicates whether signal from 2 or more pixels have been summed. |
| CCDSEC | '[1:2048,1:4102]' | CCD Section | Pixels unbinned | Area of the ccd actually read out |
| CCDSIZE | '[1:2048,1:4102]' | CCDSize | Pixels unbinned | Size of ccd in pixels |
| CD1_1 | 6.1523E-05 | WCS matrix element 1,1 | degrees/pixels | World coordinate system matrix element 1,1. |
| CD1_2 | -3.4749519E-05 | WCS matrix element 1,2 | degrees/pixels | World coordinate system matrix element 1,2. |
| CD2_1 | -3.4749519E-05 | WCS matrix element 2,1 | degrees/pixels | World coordinate system matrix element 2,1. |
| CD2_2 | -6.1519739E-05 | WCS matrix element 2,2 | degrees/pixels | World coordinate system matrix element 2,2. |
| CLOSTIME | '12:23:17.593' | Close Shutter Time | HH:MM:SS | Time the OSIRIS shutter close. Only appears if the shutter actually moved (e.g., does not appear in bias images) |
| COMMENT | This is a comment | None | N/A | Keyword used to include comments of whatever nature |
| CRPIX1 | 462.5 | Ref pix of axis 1 | pixel | Pixel in image corresponding to the RA given by CRVAL1 |
| CRPIX2 | 995.23 | Ref pix of axis 2 | pixel | Pixel in image corresponding to the DEC given by CRVAL2 |
| CRVAL1 | 1.55213538050385 | RA at Ref pix in decimal degrees | degrees | This is the Right ascension of the pixel given in CRPIX1 |
| CRVAL2 | 63.6936537290756 | DEC at Ref pix in decimal degrees | degrees | This is the declination of the pixel given in CRPIX2 |
| CSCXOFF | 34680 | TF Red Auto Adjustment X (encoder units) | Encoder units | Same as EKW16 (Default value of TF X position, set at starting time). |
| CSCYOFF | 34680 | TF Red Auto Adjustment Y (encoder units) | Encoder units | Same as EKW17 (Default value of TF Y position, set at starting time). |
| CSCZOFF | 34680 | TF Red Auto Adjustment Z (encoder units) | Encoder units | Same as EKW18 (Default value of TF Z position, set at starting time). |
| CTYPE1 | 'RA---TAN' | R.A. in tangent plane projection | N/A | System used for world coordinate projection. Must be written exactly as 'RA---TAN'. |
| CTYPE2 | 'DEC--TAN' | DEC. in tangent plane projection | N/A | System used for world coordinate projection. Must be written exactly as 'RA---TAN'. |
| DARK | 'false ' | Apply Dark | Boolean | Indicates whether the shutter open or not inspite of the value reported by EXPTIME. If "true", the shutter did not open. |
| DATASEC | '[26:1049,1:2051]' | Data Section | Pixels | Data section in binned pixels. Differ from AMPSEC because of overscan and binning. Disply use it to show only data pixels |
| DATE | '2012-02-14T16:12:52' | file creation date (YYYY-MM-DDThh:mm:ss UT) | N/A | Time stamp for fits file creation. This is not the time of observation. |
| DATE-OBS | 2012-02-14T16:12:16.632 | Time when starts the first exposure | N/A | Time stamp relative to the start of the exposure (for charge transfer mode this refers to the first exposure). |
| DEC | '+63:41:39.856' | Telescope declination (DD:PP:SS), d:m:s | DD:PP:SS | Declination the telescope is aiming to. In sessagesimal degrees. |
| DECDEG | 63.6944043136059 | Telescope declination in degrees, degrees | degrees | Declination the telescope is aiming to. In decimal degrees. |
| DEEP | 2 | Bytes per pixel | bytes | Number of bytes used to represent numbers. |
| DETECTOR | 'E2V CCD44_82_BI' | Detectors Model | N/A | Detector identification model |
| DETSEC | '[1:2048,1:4102]' | Detector Section | Pixels | Area of the detector actually used in exposure. |
| DETSIZE | '[1:4096,1:4102]' | Maximum Imaging Pixel Area | pixels | Detector size in pixels. |
| DEWPOINT | -12.3 | Ambient dew point in Celsius degrees | Degrees Celsius | Ambient dew point in Celsius degrees |
| EKW1 | 3 | Filter Wheel 1 currentPosition. | Integer | Filter Wheel 1 currentPosition. |
| EKW2 | 5 | Filter Wheel 2 currentPosition. | Integer | Filter Wheel 2 currentPosition. |
| EKW3 | 5 | Filter Wheel 3 currentPosition. | Integer | Filter Wheel 3 currentPosition. |
| EKW4 | 7 | Grism Wheel currentPosition. | Integer | Grism Wheel currentPosition. |
| EKW5 | 2 | Mask positioner currentPosition | Integer | Mask positioner currentPosition |
| EKW6 | 37634 | Red TF Displacement in Z (encoder units) | Encoder units | Tunable filter Red DisplacementZ |
| EKW7 | 69 | Red TF offset (encoder units) | Encoder unites | Tunable filter Red currentOffset |
| EKW12 | 34680 | Red TF position X (encoder units) | Encoder units | Tunable filter Red position X |
| EKW13 | 24680 | Red TF position Y (encoder units) | Encoder units | Tunable filter Red position Y |
| EKW16 | 34680 | Red TF auto adjustement X (encoder units) | Encoder units | Tunable filter Red position Auto Adjustment X |
| EKW17 | 32080 | Red TF auto adjustement Y (encoder units) | Encoder units | Tunable filter Red position Auto Adjustment Y |
| EKW18 | 34350 | Red TF auto adjustement Z (encoder units) | Encoder units | Tunable filter Red position Auto Adjustment Z |
| ELAPSED | '45.810 ' | Total elapsed time from start to end (s) | Seconds | Time difference between End and start of observation. |
| ELAPSHUT | '6.966 ' | Total elapsed time (seconds followed by ms) | Seconds | Time difference between CLOSETIME - OPENTIME, in seconds. |
| ELEVAT | 47.3367634069994 | Elevation at start of observation | Degrees | Telescope elevation at start of observations. |
| END | | | N/A | Marks end of image header |
| EQUINOX | 2000. | Epoch of the mean equinox for WCS | Years | Equinox for world coordinate system. |
| EXPMODE | 'UNIQUE ' | ExposureMode | N/A | Exposure mode, could be UNIQUE, FORWARD_START, y FORWARD_RETURN. |
| EXPTIME | 6.5 | Exposure Time in seconds | Seconds | Exposure time. Differ form ELAPSHUT because of shutter flying time. |
| EXTEND | | None | N/A | Mark end of fits header extention. |
| EXTNAME | 'CCD_1_L1_1' | Extension Name | N/A | Extension name according to detector been read, readout mode, and readout channel. |
| FILSTAT | 'COMMITED' | None | N/A | Not Used. |
| FILTER1 | 'OPEN ' | Filter identifier in wheel 1 | N/A | Position of filter wheel 1 |
| FILTER2 | 'OPEN ' | Filter identifier in wheel 2 | N/A | Position of filter wheel 2 |
| FILTER3 | 'OPEN ' | Filter identifier in wheel 3 | N/A | Position of filter wheel 3 |
| FILTER4 | 'R1000B ' | Filter 4 device identifier | N/A | Position of Grism wheel |
| FRAMESI | 8606008 | Raw Data Size in bytes | Bytes | Size of data file |
| FRAMETY | 1 | Frame Type(1:RDI,2:RDS, 3:RDW) | N/A | Frame type. RDI=modo simple, RDS= modo shutterless, RDW= modo frame transfer. |
| GAIN | 1.18 | Gain (e-/adu) | Electrons/ADU | Gain in electrons per ADU |
| GAINTYPE | 'GAIN_x4_75' | Gain requested by user | N/A | String identifying the gain mode. |
| GCOUNT | 1 | required keyword. must = 1 | | One data group. |
| GRISM | 'R500B ' | GRISM identifier | N/A | Grism identification name (duplicate value of FILTER4) |
| GTCOBID | '0001' | Observation Block | N/A | Observing block number |
| GTCPRGID | 'GTC50-11B' | Program Identifier | N/A | Unique observing program ID. |
| HBIN | 'true ' | Horizontal Binning | Boolean | Whether binning was applied in the horizontal direction. See also VBIN. |
| HEIGHT | 2348 | Telescope height above sea level (m) | Meter | Telescope altitude above sea leval in meter. |
| HUMIDITY | 33.34 | Ambient humidity in percent. | Percent | Ambient humidity in percent. |
| INHERIT | T | inherit keyword | Boolean | Either T or F. Whether extension hinerits keywords from primary extention |
| INSMODE | | Instrument Mode | N/A | not defined |
| INSTRUME | 'OSIRIS ' | Instrument Name | N/A | Unique instrument name |
| IPA | 0.23 | Instrument position angle in degrees, degrees | Degrees | Instrument position angle |
| LATITUDE | 28762000 | Telescope latitude (degrees), +28:45:43.2 | Degrees | Telescpe latitude |
| LONGITUD | 17877639 | Telescope longitude (degrees), +17:52:39.5 | Degrees | Telescope longitude |
| LOOPSHIF | | | Integer | Times charge displacement is repeated, in charge transfer/shaffling mode. |
| LST | '+23:58:53.137' | Local sidereal time (HH:MM:SS)., h:m:s | HH:MM:SS | Local sidereal time. |
| M2RX | 0.00024826789740 | GTC secondary mirror RX position | Radians | GTC secondary mirror RX position |
| M2RY | -7.7156859333E-05 | GTC secondary mirror RY position | Radians | GTC secondary mirror RY position |
| M2UX | -0.90281625366211 | GTC secondary mirror UX position | mm | GTC secondary mirror UX position |
| M2UY | 3.28916454315186 | GTC secondary mirror UY position | mm | GTC secondary mirror UY position |
| M2UZ | -0.71310837604523 | GTC secondary mirror UZ position | mm | GTC secondary mirror UZ position |
| MASKNAME | 'NOMASK ' | Mask name | N/A | Multi-object spectroscopy mask name. |
| MJD-OBS | 55971.6491228745 | Modified Julian day at observation start | Days | Modified Julian day at observation start |
| MOSAIC | 'true ' | Mosaic active or not | N/A | Whether CCD mosaic is active or not |
| MOVTYPE | 'ONLYDOWN' | Direction of charge desplacement | N/A | Direction of charge desplacement: can be “ONLYDOWN”, "ONLYUP","ALT_START_UP", "ALT_START_DOWN" |
| NAMPS | 2 | Number of channels | Integer | Number of amplifier used during CCD readout |
| NAXIS | 2 | Number of data axis | Integer | Number of data axis, zero on primary fits header extention. |
| NAXIS1 | 1049 | length of data axis 1 | Pixels | Number of data pixel in axis 1 |
| NAXIS2 | 2051 | length of data axis 2 | Pixels | Number of data pixel in axis 2 |
| NSHIFTS | 20 | Number of lines charges are moved on the CCD | Integer | Number of lines charges are moved on the CCD in charge transfer/shaffling mode. |
| NUM_IMAG | 1 | Total number of images into the sequence | Integer | Sequence total number of images in frame transfer mode. |
| NUM_INDX | 0 | Image Index into sequence. Starts from 0. | Integer | Image Index within sequencein in frame transfer mode. Starts from 0. |
| NUM_ROIS | 1 | Number of windows | integer | Number of CCD windows, maximum 5. |
| NUM_SHIF | 2 | Number of times charges are moved | Integer | Number of times charges are moved in charge transfer/shaffling mode |
| OBJECT | 'NGC1234' | OSIRIS comment | N/A | Should be the user defined target name. |
| OBSCLASS | 'science ' | Observation class | N/A | This should be the observation class, like SCIENCE or CALIBRATION. Duplication of OBSTYPE |
| OBSERVAT | 'ORM ' | Observatory name | N/A | Perhaps the name of the observatory (Roque de los Muchachos). |
| OBSERVER | 'SA ' | Observer Name | N/A | Observer name (SA = support astronomer). |
| OBSMODE | 'OsirisDark' | Observation Mode | N/A | Instrument observing mode (for data factory use). |
| OBSTYPE | 'Calib ' | Observation Type | N/A | Observation type, should be either SCIENCE or CALIB. |
| OPENTIME | '12:23:17.593' | Open Shutter Time | HH:MM:SS | Time the OSIRIS shutter did open. Only appears if the shutter actually moved (that is, does not appear in bias images). |
| OPTCENTX | 1000. | OSIRIS Optical Center X | Pixels | Position of optical center in the X direction |
| OPTCENTY | 1001. | OSIRIS Optical Center Y | Pixels | Position of optical center in the Y direction |
| ORIGFILE | 'Jan14_050116.fits' | Filename | N/A | Original FITS file name |
| ORIGIN | 'GRANTECAN' | Organization responsible for creating the FITS | N/A | |
| OSFILT | ' ' | Order Sort Filter identifier | N/A | Order Sort Filter identifier |
| OSISTAT | 1 | OSIRIS status: 1=ok | N/A | Flag to indicate osiris status. 1=OK |
| OSIVERS | 1. | OSIRIS software and hardware version | N/A | OSIRIS software and hardware version |
| OSWAV | 4500. | Order Sort Filter central wavelength | Angstrom | Order Sort Filter central wavelength |
| OUTMODE | 'TWOCCDS_A' | OutputMode | N/A | CCD readout output mode. |
| PCOUNT | 0 | required keyword. must = 0 | N/A | Size of special data area. |
| PI | 'mespinoza' | Personal Investigator | N/A | Principal investigator of the project for which the observation was taken. |
| PRESCAN | 'true ' | Prescan active or not | Boolean | Whether the prescan was active or not. |
| PRESSURE | 777.289978027344 | Ambient atmospheric pressure (hPascal) | hectoPascal | Ambient atmospheric pressure. |
| RA | '+9:35:13.247' | Telescope right ascension (HH:MM:SS) , h:m:s | HH:MM:SS.sss | Telescope right ascension. |
| RADEG | 143.80519462267 | Telescope right ascension in decimal degrees. | Degrees | Telescope right ascension in decimal degrees. |
| RADESYS | 'FK5 ' | Equatorial coordinate system | N/A | Reference system for World Coordinate System. |
| READTIME | '05:35:17.972' | Approximate time when read starts | HH:MM:SS | Approximate time when read starts!! NOT CLEAR |
| ROI_X | 2098 | X-Size of windows in pixels | Unbinned Pixels | X-Size of the CCD area actually readout, unaffected by binning. Equal to the whole CCD, except when using windows. |
| ROI_Y | 4102 | Y-Size of windows in pixels | Unbinned Pixels | Y-Size of the CCD area actually readout, unaffected by binning. Equal to the whole CCD, except when using windows. |
| ROI_1X | 0 | X-Origin of ROI-1 in RDI-RDW | Pixels | X of lower left corner position of the window. Unclear description, what is RDI-RDW? |
| ROI_1Y | 0 | Y-Origin of ROI-1 in RDI-RDW | Pixels | Y of lower left corner position of the window. Unclear description, what is RDI-RDW? |
| ROI_2X | 0 | X-Origin of ROI-1 in RDI-RDW | Pixels | If a second window is defined, this is its X of lower left corner position. |
| ROI_2Y | 0 | Y-Origin of ROI-1 in RDI-RDW | Pixels | If a second window is defined, this is its Y of lower left corner position. |
| ROTANG | -61.8845 | Rotator position angle in degrees | Degrees | Rotator position angle in degrees. |
| RSPEED | 100 | Readout Speed Khz | kHz | CCD read out speed in kHz |
| SEQUENCE | 'SIMPLE ' | Basic sequence mode | N/A | CCD read out sequance mode |
| SIMPLE | T | file does conform to FITS standard | Boolean | Whether the file conform to fits standard. |
| SIMVAL | 0 | SimulateVal | N/A | Should be always 0. Data are never simulated! |
| SIMTYPE | 0 | SimulateType | N/A | Should be always 0. Data are never simulated! |
| SIMULATE | 'false ' | Simulate active or not | Boolean | Should be always false. Data are never simulated! |
| SLITPA | 0. | Slit pa | Degrees | Slit position angle in degrees from North toward east |
| SLITW | 1. | Slit width | Arcsec | Slit width in arcsec |
| TAMBIENT | 0.23 | Ambient temperature in Celsius degrees | Degrees Celsius | Ambient temperature in Celsius degrees |
| TELESCOP | 'GTC ' | Telescope | N/A | Telescope name |
| TFBANDW | 14.93255615 | filter bandwidth after z processing | Angstrom | Tunable filter band width. |
| TFID | 'TF_RED ' | TF identifier | N/A | Tunable filter unique name. |
| TFTEMP | ' ' | TF temperature | Degrees Celsius | Tunable filter temperature. |
| TFWAVEL | 8234.4411 | filter wavelength after z processing | Angstrom | Tunable filter central wavelength. |
| TITLE | ' ' | Title given to the image | N/A | Image title. Duplicate OBJECT, should be removed! |
| TRIMSEC | '[280:1049,1:2000]' | TRIM section | Pixels | Trim section. Should indicate the ccd vignetted region. |
| VBIN | 'true ' | Vertical Binning | Boolean | Whether binning was applied in the vertical direction. See also HBIN. |
| WINDDIRE | 177. | Wind direction (from) in degrees from N to E. | Degrees | Wind direction (from). In degrees from north toward east. |
| WINDSPEE | 5.96 | Wind speed in m/s | m/s | Wind speed in m/s |