Key

Type

Method of derivation

Description

SIMPLE

String

None

Mandatory FITS keyword

BITPIX

Int

None

Mandatory keyword describing the number of bits per pixel in the data.
Permitted values are: 8, 16, 32, 64, -32, -64.

NAXIS

Int

None

Number of axes in the associated data array.

NAXISn

Int

None

Number of elements along axis ‘n’.

END

String

None

Keyword marking the end of the header.

Key

Type

Method of derivation

Description

BUNIT

String

Mode of raw values.

The physical unit of the data values after application of BZERO and BSCALE according to Pence (2010) (physical_value in BUNIT = BZERO + BSCALE× array_value.)

Allowable units and prefixes are stated in Pence (2010), Tables 3, 4, and 5 (and anticipated to be typically ADU)

BZERO

Float

Calculation of new zero point in bit depth.

see Pence (2010), and BUNIT, default BZERO=0

BSCALE

Int

None

Number of axes in the associated data array.

BLANK

Int

None

Number of elements along axis ‘n’.

DATE

String

Time of HDU creation

UTC time of HDU creation.

DATE-OBS

String

Time of first frame used in creating calibrated frame.

UTC time of beginning of observations in calibrated frame.

DATE-BGN

String

Mode of raw values.

Start date / time of instrument program.

DATE-END

String

Mode of raw values.

End date / time of instrument program.

ORIGIN

String

Mode of raw values.

Organization responsible for creating the FITS file.

TELESCOP

String

Mode of raw values.

Telescope used to acquire data in the FITS file.

OBSERVAT

String

Mode of raw values.

The physical entity, located in a defined location, which provides the resources necessary for the installation of an instrument.

NETWORK

String

Mode of raw values.

Organizational entity of a series of instruments with similar characteristics or goals that operates in some coordinated manner or produces data with some common purpose.

INSTRUME

String

Mode of raw values.

Instrument used to acquire the data in the FITS file.

WAVELNTH

Float

Mode of raw values.

Coarse wavelength band, in nanometers, of observation.

OBSERVER

String

Mode of raw values.

The value field shall contain a character string identifying the DKIST operator who acquired the data associated with the header.

OBJECT

String

Mode of raw values.

A name for the observed object.

COMMENT

String

Mode of raw values.

Any comments regarding the FITS file.

Key

Type

Method of derivation

Description

WCSAXESa

Int

Calculated from calibrated data.

Number of axes in the WCS description. This keyword, if present, must precede all WCS keywords except NAXIS in the HDU. The value of WCSAXES may exceed the number of pixel axes for the HDU. (see also Pence et al. 2010)

Possible values for a: “ “ (blank), or “A” through “Z”

Default value: “ “ (blank, indicating the primary WCS name; “A” through “Z” indicate an alternate WCS)

WCSNAMEa

String

Calculated from calibrated data.

Name of the WCS (see Pence et al, 2010). The index a is present for an alternate WCS (see WCSAXESa)

CRPIXna

Float

Calculated from calibrated data.

The value field shall contain a floating point number, identifying the location of a reference point along axis n, in units of the axis index. This value is based upon a counter that runs from 1 to NAXISn with an increment of 1 per pixel. The reference point value need not be that for the center of a pixel nor lie within the actual data array. Use comments to indicate the location of the index point relative to the pixel.

DKIST pointing data will be relative to the boresight of the telescope defined by the WFC Context Viewer that will center an image of the GOS pinhole on its detector using a 10 nm wavelength band centered on 525 nm. The same pinhole image will be used by all instruments as reference for determining the pointing of the instrument in relation to the WFC Context Viewer. The index a is present for an alternate WCS (see WCSAXESa)

CRDATEna

String

Calculated from calibrated data.

Date of last update of CRPIXn and CDELTn value

The index a is present for an alternate WCS (see WCSAXESa) The value will get updated upon realignment of the data source with the WFC Context Viewer (see CRPIXna)

CRVALna

Float

Calculated from calibrated data.

The value field shall contain a floating point number, giving the value of the coordinate specified by the CTYPEn keyword at the reference point CRPIXn.

DKIST values for this entry will be determined at the wavelength of the WFC Context Viewer, which covers a band of 10 nm centered on 525 nm. The value will not be corrected for differential refraction of Earth’s atmosphere.

The index a is present for an alternate WCS (see WCSAXESa)

CDELTna

Float

Calculated from calibrated data.

Pixel spacing along axis n (Thompson, 2006)

The index a is present for an alternate WCS (see WCSAXESa)

CUNITna

String

Calculated from calibrated data.

The unit of the value contained in CDELTn (Thompson, 2006) The index a is present for an alternate WCS (see WCSAXESa)

CTYPEna

String

Calculated from calibrated data.

A string value labeling each coordinated axis.

This keyword shall be used to describe image data axes, see e.g. Thompson (2006)

This keyword shall be used to describe spectro-polarimeteric axes that the data may have; see also e.g. Section 5.2 in Greisen (2006)

The index a is present for an alternate WCS (see WCSAXESa)

PCi_ja

Float

Calculated from calibrated data.

See e.g. Pence et al. (2010)

The index a is present for an alternate WCS (see WCSAXESa)

LONPOLEa

Float

Calculated from calibrated data.

See Calabretta (2002) and Thompson (2006)

LATPOLEa

Float

Calculated from calibrated data.

See Calabretta (2002) and Thompson (2006)

TAZIMUTH

Float

Mean of raw values.

raw Telescope azimuth angle in [deg]

TELEVATN

Float

Mean of raw values.

raw Telescope elevation angle in [deg]

TELTRACK

String

Mode of raw values.

Tracking Mode of the Telescope. Possible values:

“None, Fixed Solar Rotation Tracking, Differential Rotation Tracking, Scanning Motion (Random, or Grid, or Raster, or Spiral)”

TTBLANGL

Float

Mean of raw values.

Telescope Coude table angle

TTBLTRCK

String

Mode of raw values.

Coude table tracking mode.

Values: (stepped) parallactic, fixed angle on Sun (e.g. N-S), fixed difference angle between coude and tel. azimuth, fixed coude table angle

CRDERna

CSDERna

DV

Key

Type

FITS Comment

Method of derivation

Description

ID___001

String

DKISTFITSHeaderVersion

Mode of raw values.

Version of the DKIST FITS Header format

ID___002

String

FileID

Calculated from calibrated data.

Unique ID of this FITS file

ID___003

String

CheckSum

Calculated from calibrated data.

Checksum for data integrity verification.

ID___004

String

DataSetID

Mode of raw values.

Unique ID of the DataSet associated with these data.

ID___005

String

DataSetParametersID

Mode of raw values.

Unique ID of the DataSetParameters used to configure the InstrumentProgram associated with these data.

ID___006

String

DataSetParameterSequenceID

Mode of raw values.

Unique ID of the DataSetParameterSequence used to configure the InstrumentProgram associated with these data.

ID___007

String

InstrumentProgramID

Mode of raw values.

Unique ID of the InstrumentProgram associated with these data.

ID___008

String

InstrumentScriptID

Mode of raw values.

Unique ID identifying the instrument script that was executed to acquire this data.

ID___009

String

InstrumentProgramParametersID

Mode of raw values.

Unique ID of the parameters used to configure the InstrumentProgram associated with these data.

ID___010

String

ObservingProgramID

Mode of raw values.

Unique ID of the original ObservingProgram associated with the generation of these data.

ID___011

String

ObservingProgramAsRunID

Mode of raw values.

Unique ID of the ‘as run’ ObservingProgram associated with the generation of these data.

ID___012

String

ObservingScriptId

Mode of raw values.

Unique ID of the Observing Program Script used to acquire this data.

ID___013

String

ObservingProgramParametersID

Mode of raw values.

Unique ID of the OCS level parameters used to configure the ObservingProgram associated with these data.

ID___014

String

TelescopeParametersID

Mode of raw values.

Unique ID of the TCS level parameters used to configure the ObservingProgram associated with these data.

ID___015

String

ExperimentID

Mode of raw values.

Unique ID of the experiment associated with the generation of these data.

ID___016

String

ProposalID

Mode of raw values.

Unique ID of the proposal associated with the experiment associated with the generation of these data.

ID___017

String

InvestigatorID

Mode of raw values.

Unique ID identifying the Principal Investigator associated with the experiment.

Key

Type

FITS Comment

Method of derivation

Description

DKIST001

String

OCSMode

Mode of raw values.

Mode the telescope was operated in:

‘Auto’: Data were acquired as part of a regular, automatic execution of an Observing Program

‘Manual’: Data were acquired executing either a part of an or a complete Observing Program manually.

DKIST002

String

ObservingProgramRunMode

Mode of raw values.

‘Full’: Data were acquired as part of a regular execution of an Observing Program ‘Test’: Data were acquired as part of a test execution of (parts of) an Observing Program

DKIST003

String

ObservingProgramTask

Mode of raw values.

Observing Task addressed by the Observing Program that led to the acquisition of this data. For calibrated data, ‘Observation’ is the only valid value.

DKIST004

String

InstrumentProgramTask

Mode of raw values.

Instrument Program Task addressed by the Instrument Program that led to the acquisition of this data. For calibrated data, ‘Observation’ is the only valid value.

DKIST005

String

FIDOConfiguration

Mode of raw values.

The DKIST FIDO configuration in the following format: [M9aStatus,CL2,CL2a,CL3,CL3a,CL4]

DKIST006

String

InstrumentHealthStatus

Worst health status form frames that made up the calibrated frame.

Worst health status of the instrument during data acquisition (Good, Ill, Bad)

DKIST007

Bool

EngineeringDataFlag

All DKIST007 values == 0.

0: Data belongs to a regular science experiment execution.

1: Data is ‘engineering’ data. Scientific value of data not guaranteed.

DKIST008

String

StartDateOfValidity

Mode of raw values.

Start of date range for validity of data, e.g.calibration data. Equal to NA, if not applicable (e.g. science data)

DKIST009

String

EndDateOfValidity

Mode of raw values.

End of date range for validity of data, e.g. calibration data. Equal to NA, if not applicable (e.g. science data)

DKIST010

Int

NumberOfRepeats

Mode of raw values.

Number (> 0) of repeated DataSetParametersequences within an InstrumentProgram.

VBI/DL-NIRSP: Number of field scans to acquire for the observation:

N=-1 (loop until interrupted), N>=1

DKIST011

Int

RepeatNumber

Mode of raw values.

Number (0 < RepeatNumber ≤ NumberOfRepeats) describing the current repetition of the DataSetParametersequence within an InstrumentProgram. VBI/DL-NIRSP: RepeatNumber = Current field scan repetition

DKIST012

Float

RepeatCadence

Mean of raw values.

Cadence, in seconds, of the DataSetParameterSequences

VBI/DL-NIRSP: Cadence of field scans

DKIST013

Int

LightLevel

Mode of raw values.

Number of entries in the FITS table accompanying the data containing the value of the telescope light level during data acquisition.

Key

Type

FITS Comment

Method of derivation

Description

CAM__001

String

CameraUniqueID

Mode of raw values.

Unique ID of camera used to acquire the data

CAM__002

Float

FPAExposureTime

Calculated from calibrated data.

Total duration of exposure to photons, in milliseconds, that resulted in the FPAs within the FPA-set contained in this FITS file.

CAM__003

Float

FPAFrameRate

Mode of raw values.

Average acquisition rate of FPAs, in Hertz

CAM__004

Float

CamExposureTime

Mode of raw values.

Duration of photosensitive sensor exposure to photons per single sensor read-out

CAM__005

Float

CamFrameRate

Mode of raw values.

Rate of photosensitive sensor read-outs

CAM__006

Int

ChipDimensionX

Mode of raw values.

Value describing the number photosensitive pixels on the camera sensor, in X direction

CAM__007

Int

ChipDimensionY

Mode of raw values.

Value describing the number photosensitive pixels on the camera sensor, in Y direction

CAM__008

Int

HardwareBinningX

Mode of raw values.

Value describing the binning performed in hardware in pixels, in X direction

Equals 1 if disabled

CAM__009

Int

HardwareBinningY

Mode of raw values.

Value describing the binning performed in hardware in pixels, in Y direction

Equals 1 if disabled

CAM__010

Int

SoftwareBinningX

Mode of raw values.

Binning performed by software in pixels, after hardware binning, in pixels, X

Equals 1 if disabled

CAM__011

Int

SoftwareBinningY

Mode of raw values.

Binning performed by software in pixels, after

hardware binning, in pixels, Y Equals 1 if disabled

CAM__012

Int

NumberOfFPAs

Sum of raw values.

Number of FullyProcessedAccumulators generated with the DataSetParameters

CAM__013

Int

CurrentFPA

Mean of raw values

Number N of the current FPA generated with the DataSetParameters

1 ≤ N ≤ NumberOfFPAs

CAM__014

Int

AccumulationsPerFPA

Mode of raw values.

Number of accumulations per FPA

CAM__015

Int

ROI1OriginX

Mode of raw values.

Region Of Interest 1 X - Origin coordinate in pixels

CAM__016

Int

ROI1OriginY

Mode of raw values.

Region Of Interest 1 Y - Origin coordinate in pixels

CAM__017

Int

ROI1SizeX

Mode of raw values.

Region Of Interest 1 X - Size in pixels

CAM__018

Int

ROI1SizeY

Mode of raw values.

Region Of Interest 1 Y - Size in pixels

CAM__019

Int

ROI2OriginX

Mode of raw values.

Region Of Interest 2 X - Origin coordinate in pixels

Keyword not present, if not used

CAM__020

Int

ROI2OriginY

Mode of raw values.

Region Of Interest 2 Y - Origin coordinate in pixels

Keyword not present, if not used

CAM__021

Int

ROI2SizeX

Mode of raw values.

Region Of Interest 2 X - Size in pixels

Keyword not present, if not used

CAM__022

Int

ROI2SizeY

Mode of raw values.

Region Of Interest 2 Y - Size in pixels

Keyword not present, if not used

CAM__023

Int

ROI3OriginX

Mode of raw values.

Region Of Interest 3 X - Origin coordinate in pixels

Keyword not present, if not used

CAM__024

Int

ROI3OriginY

Mode of raw values.

Region Of Interest 3 Y - Origin coordinate in pixels

Keyword not present, if not used

CAM__025

Int

ROI3SizeX

Mode of raw values.

Region Of Interest 3 X - Size in pixels

Keyword not present, if not used

CAM__026

Int

ROI3SizeY

Mode of raw values.

Region Of Interest 3 Y - Size in pixels

Keyword not present, if not used

CAM__027

Int

ROI4OriginX

Mode of raw values.

Region Of Interest 4 X - Origin coordinate in pixels

Keyword not present, if not used

CAM__028

Int

ROI4OriginY

Mode of raw values.

Region Of Interest 4 Y - Origin coordinate in pixels

Keyword not present, if not used

CAM__029

Int

ROI4SizeX

Mode of raw values.

Region Of Interest 4 X - Size in pixels

Keyword not present, if not used

CAM__030

Int

ROI4SizeY

Mode of raw values.

Region Of Interest 4 Y - Size in pixels

Keyword not present, if not used

Key

Type

FITS Comment

Method of derivation

Description

PAC__001

String

UpGOSLinPolarizer

Mode of raw values.

Value indicating status of Upper GOS Linear Polarizer slide. OutOfBeam, IDOfLinearPolarizerOpticsInBeam

PAC__002

Float

UpGOSLinPolarizerAngle

Mean of raw values.

Current Rotation Angle of the Linear Polarizer Optics. Keyword not present, if not used

PAC__003

String

UpGOSRetarder

Mode of raw values.

Value indicating status of Upper GOS Retarder slide. OutOfBeam, IDOfRetarderOpticsInBeam

PAC__004

Float

UpGOSRetarderAngle

Mean of raw values.

Current Rotation Angle of the Retarder Optics

Keyword not present, if not used

PAC__005

Float

UpGOSRetarderTemp

Mode of raw values.

Current Temperature of the Retarder Optics Keyword not present, if not used

PAC__006

String

UpGOSLightSource

Mode of raw values.

Value indicating status of Upper GOS Light Source slide. OutOfBeam, IDOfBroadbandLightSourceInBeam

PAC__007

String

LoGOSObject

Mode of raw values.

Value indicating status of Lower GOS Slide Object.

FieldStop, Dark, Pinhole, LineGrid, NonRedundantArray, InterferometerSphere, Occulter

PAC__008

Float

LoGOSFieldStopDia

Mean of raw values.

Aperture diameter of the Lower GOS FieldStop

Keyword not present, if not used

PAC__009

Float

LoGOSPinholeDia

Mean of raw values.

Diameter of the Lower GOS Pinhole

Keyword not present, if not used

PAC__010

String

LoGOSPinholeType

Mode of raw values.

Type of Lower GOS pinhole. Normal, Inverse

Keyword not present, if not used

PAC__011

Float

LoGOSLineGridDist

Mean of raw values.

Distance between lines of the Lower GOS Line Grid. Keyword not present, if not used

PAC__012

String

LoGOSNRAType

Mode of raw values.

Type of the Non- RedundantArray Target Type

AirForce, MultiPinhole

Keyword not present, if not used

PAC__013

Float

LoGOSOcculterPosAngle

Mean of raw values.

Position angle of the Lower GOS Occulter Keyword not present, if not used

PAC__014

String

DKISTPolarizationCalX12ID

Mode of raw values.

Reference ID of the DKIST Polarization Calibration Data (Matrix for M1 and M2) valid for this data (PolCalX-matrices must be selected to be adequate for the wavelength range, and within a ‘valid date range’)

Keyword not present, if not used

PAC__015

String

DKISTPolarizationCalX34ID

Mode of raw values.

Reference ID of the DKIST Polarization Calibration Data (Matrix for M3 and M4) valid for this data (PolCalX-matrices must be selected to be adequate for the wavelength range, and within a ‘valid date range’)

Keyword not present, if not used

PAC__016

String

DKISTPolarizationCalX56ID

Mode of raw values.

Reference ID of the DKIST Polarization Calibration Data (Matrix for M5 and M6) valid for this data (PolCalX-matrices must be selected to be adequate for the wavelength range, and within a ‘valid date range’)

Keyword not present, if not used

PAC__017

String

DKISTPolarizationCalXInstID

Mode of raw values.

Reference ID of the DKIST Polarization Calibration Data (Matrix for M7 to the instrument) valid for this data

(PolCalX-matrices must be selected to be adequate for the wavelength range, and within a ‘valid date range’)

Keyword not present, if not used

Key

Type

FITS Comment

Method of derivation

Description

AO___001

Int

HOAOFriedParameterVals

Sum of raw values.

Number of entries in the FITS table included in this file containing the value of Fried's parameter during data acquisition.

Keyword not present, if not used

AO___002

Bool

HOAOLockStatus

All AO___002 values == 1.

Lock status of HOAO during data acquisition.

0: HOAO was unlocked for some duration of data acquisition

1: HOAO was locked for the complete duration of data acquisition

Keyword not present, if not used

AO___003

Float

HOAOLockOffPointingX

Mode of raw values.

Current Lockpoint offpointing in X of the HOAO WFS in pixels relative to WFC

Context Viewer defined telescope boresight

AO___004

Float

HOAOLockOffPointingY

Mode of raw values.

Current Lockpoint offpointing in Y of the HOAO WFS in pixels relative to WFC

Context Viewer defined telescope boresight

AO___005

Float

LimbSensorRadialSetPos

Mode of raw values.

Radial set position with respect to the limb as seen at the sensing wavelength of the Limb Sensor

= 0 indicates occulting at the limb

> 0 indicates over-occulting, i.e. the limb is not visible

< 0 indicates under-occulting i.e. the limb is visible

Keyword not present, if not used

AO___006

Float

LimbSensorRate

Mode of raw values.

Frequency with which the Limb Sensor position is read out

Keyword not present, if not used

Key

Type

FITS comment

Method of derivation

Description

WS___001

Float

WeathWindSpeed

Mean of raw values.

DKIST Local Outside Wind Speed (m/s)

WS___002

Int

WeathWindDirection

Mean of raw values.

DKIST Local Outside Wind Direction North: 0 deg East: 90 deg South: 180 deg West: 270 deg

WS___003

Float

WeathOutsideTemperature

Mean of raw values.

DKIST Local Outside Tempertature (C)

WS___004

Float

WeathRelativeHumidity

Mean of raw values.

DKIST Local Outside Relative Humidity (%)

WS___005

Float

WeathDewPoint

Mean of raw values.

DKIST Local Outside Dew Point (C)

WS___006

Float

WeathBarometricPressure

Mean of raw values.

DKIST Local Outside Barometric Pressure (hPa)

WS___007

Float

WeathSkyBrightness

Mean of raw values.

DKIST Local Outside Sky Brightness (ppm)

Key

Type

FITS Comment

Method of derivation

Description

VBI__001

Float

InterferenceFilterFWHM

Mean of raw values.

Full Width at Half Maximum spectral transmission. (nm)

VBI__002

Int

FilterWheelPosition

Mode of raw values.

Filterwheel position.

VBI__003

String

SpatialStepPattern

Mode of raw values.

Selected pattern with which the FieldOfView is sampled.

Keyword not present, if not used

VBI__004

Int

NumberOfSpatialSteps

Mode of raw values.

Value indicating the number of images

belonging to the scanned FieldOfView. Keyword not present, if not used

VBI__005

Int

CurrentSpatialStep

Mode of raw values.

Value indicating the current image position belonging to the scanned FieldOfView.

1 ≤ CurrentSpatialStep ≤ NumberOfSpatialSteps

Keyword not present, if not used

VBI__006

Bool

Processed

Mode of raw values.

Value indicating whether the image has been processed by algorithms (e.g. reconstruction algorithms etc.) or not.

Key

Type

FITS Comment

Method of derivation

Description

VTF__001

Float

FilterFWHM

Mean of raw values.

Full Width at Half Maximum spectral transmission at the current prefilter central wavelength.

VTF__002

Int

FilterWheelPosition

Mode of raw values

Filter wheel position of the current prefilter.

VTF__003

Float

WavelengthRangeMinimum

Min of VTF__003.

Minimum wavelength scanned within the current prefilter bandpass.

VTF__004

Float

WavelengthRangeMaximum

Max of VTF__004.

Maximum wavelength scanned within the current prefilter bandpass.

VTF__005

Int

NumberOfSpectralSteps

Sum of raw values.

Number of spectral steps performed by the FPI(s).

VTF__006

Int

CurrentSpectralStep

Mode of raw values.

Current spectral step in scan (1 ≤ CurrenSpectralStep ≤ NumberOfSpectralSteps)

VTF__007

Float

CurrentSpectralStepWaveL

Mean of raw values.

Wavelength at current spectral step.

VTF__008

Int

NumberOfImagesPerSpectralStep

Sum of raw values.

Number of images acquired at one particular spectral step (and modulation configuration)

VTF 009-049

Reserved for parameters describing the FPI configurations,

TBD

Values of parameters describing the Fabry-Perot Etalon configurations (e.g. peak/central wavelengths, voltages, etc)

VTF 050-079

Reserved for parameters describing the Polarization Modulator configurations,

TBD

Values of parameters that describe the modulation state in the SysOutput (t0, rate, state at t0, number of modulation states, number of accumulations per modulation state, modulation scheme, voltage for each discrete state, demodulation table, etc.)

Key

Type

FITS Comment

Method of derivation

Description

ViSP_001

Int

ArmID

Mode of raw values.

Identifier for ViSP arm that generated the data: 1, 2, 3

ViSP_002

Float

ArmPosition

Mean of raw values.

Angular position of the arm.

ViSP_003

Float

ArmFocus

Mean of raw values.

Location of the focus stage of the arm.

ViSP_004

String

FilterID

Mode of raw values.

Unique ID of the filter in use

ViSP_005

Float

FilterWavelength

Mean of raw values.

Central wavelength of filter in use

ViSP_006

Float

FilterFWHM

Mean of raw values.

Full Width at Half Maximum spectral transmission at the current filter central wavelength in use

ViSP_007

String

PolarimeterMode

Mode of raw values.

Polarimeter Mode with which these data were acquired: Full Stokes, Stokes-I, Other(?)

ViSP_008

String

ModulatorID

Mode of raw values.

Unique identifier of the modulator.

ViSP_009

String

ModulationType

Mode of raw values.

The type of motion used by the modulator:

“discrete, continuous”

ViSP_010

String

ModulatorT0

Mode of raw values.

Reference time for the Modulator motion. Unit is TBD.

ViSP_011

Float

ModulationRate

Mean of raw values.

Rate at which states are to be acquired, in Hertz.

ViSP_012

Int

ModulationStateNumAtT0

Mean of raw values.

Integer number identifier corresponding to the particular state defined by the position of the modulator at its reference time.

ViSP_013

Int

ModulationStateAngAtT0

Mean of raw values.

Modulator angle corresponding to the modulation state at T0.

ViSP_014

Int

NumberOfStates

Mode of raw values.

Number of states to be acquired: NumberOfStates ≥ 1

ViSP_015

Int

CurrentStateNumber

Mode of raw values.

Number of the current state: 1 ≤ CurrentStateNumber ≤ NumberOfStates

ViSP_016

String

GratingID

Mode of raw values.

Unique identifier of the grating in use.

ViSP_017

Float

GratingConstant

Mean of raw values.

Grating constant.

ViSP_018

Float

GratingBlazeAngle

Mean of raw values.

Grating blaze angle.

ViSP_019

Float

GratingAngle

Mean of raw values.

Grating angle with respect to incident beam.

ViSP_020

String

SlitID

Mode of raw values.

UniqueID of the slit assembly in use

ViSP_021

Float

SlitWidth

Mean of raw values.

Width of the slit in use

ViSP_022

Float

SlitSteppingSize

Mean of raw values.

Single step size of the slit for this observation

Keyword not present, if not used

ViSP_023

Float

SlitScanVelocity

Mean of raw values.

Slit move velocity for this observation [ViSP intensity mode only]

Keyword not present, if not used

ViSP_024

Int

NumberOfSpatialSteps

Mean of raw values.

Value indicating the number of images belonging to the scanned FieldOfView. Keyword not present, if not used

ViSP_025

Int

CurrentSpatialStep

Mean of raw values.

Value indicating the current image position belonging to the scanned FieldOfView. 1≤CurrentSpatialStep≤NumberOfSpatialSte ps

Keyword not present, if not used

ViSP_026

Float

SlitSelectorPosition

Mode of raw values.

Position of the slit selector stage.

ViSP_027

Float

SlitTranslationPosition

Mode of raw values.

Position of the slit translation stage.

ViSP_028

Float

FoldMirrorPosition

Mode of raw values.

Position of the fold mirror stage.

ViSP_029

String

ViSPSoftwareVersion

Mode of raw values.

Version of the ViSP Instrument Software

Key

Type

FITS Comment

Method of derivation

Description

DLN__001

String

ArmID

Mode of raw values.

Identifier for DL-NIRSP arm that generated the data: VIS, JBand, HBand

DLN__002

Float

ArmPosition

Mean of raw values.

Angular position of the arm.

DLN__003

Float

ArmFocus

Mean of raw values.

Location of the focus stage of the arm.

DLN__004

String

FilterID

Mode of raw values.

Unique ID of the filter in use

DLN__005

Float

FilterWavelength

Mean of raw values.

Central wavelength of filter in use

DLN__006

Float

FilterFWHM

Mean of raw values.

Full Width at Half Maximum spectral transmission at the current filter central wavelength in use

DLN__007

String

PolarimeterMode

Mode of raw values.

Polarimeter Mode with which these data were acquired: Full Stokes, Stokes-I, Other(?)

DLN__008

String

ModulatorID

Mode of raw values.

Unique identifier of the modulator.

DLN__009

String

ModulationType

Mode of raw values.

The type of motion used by the modulator:

“discrete, continuous”

DLN__010

String

ModulatorT0

Mode of raw values.

Reference time for the Modulator motion. Unit is TBD.

DLN__011

Float

ModulationRate

Mean of raw values.

Rate at which states are to be acquired, in Hertz.

DLN__012

Int

ModulationStateNumAtT0

Mean of raw values.

Integer number identifier corresponding to the particular state defined by the position of the modulator at its reference time.

DLN__013

Int

ModulationStateAngAtT0

Mean of raw values.

Modulator angle corresponding to the modulation state at T0.

DLN__014

Int

NumberOfStates

Mode of raw values.

Number of states to be acquired: NumberOfStates ≥ 1

DLN__015

Int

CurrentStateNumber

Mode of raw values.

Number of the current state: 1 ≤ CurrentStateNumber ≤ NumberOfStates

DLN__016

String

GratingID

Mode of raw values.

Unique identifier of the grating in use.

DLN__017

Float

GratingConstant

Mean of raw values.

Grating constant.

DLN__018

Float

GratingBlazeAngle

Mean of raw values.

Grating blaze angle.

DLN__019

Float

GratingAngle

Mean of raw values.

Grating angle with respect to incident beam.

DLN__020

Int

NumberOfDataCycles

Mode of raw values.

The number of data cycles that should occur for each mosaic tile. A data cycle can be a single or multiple modulation states. A modulation cycle is defined in discrete sampling by the collection of state values. In continuous sampling, it is defined as one half-rotation of the modulator.

DLN__021

String

CoAddMode

Mean of raw values.

Defines how data were coadded by the

detector. Values are defined as follows: State: All coadded exposures for a single state are acquired prior to progressing to the next modulation state (discrete modulation).

Sequence: The full discrete modulation sequence is cycled through a number of times equivalent to the number of coadds. Half-rotation: States of the first half rotation are coadded with comparable states of the second half rotation.

None: All exposures are saved without coadding.

DLN__022

String

FeedOpticsFRatio

Mean of raw values.

Configuration of the DL-NIRSP Feed Optics:

F/24, F/62

DLN__023

String

IFUInBeam

Mean of raw values.

Value indicating BiFOIS-IFU that was used for this observation:

IFU-36, IFU-72

DLN__024

String

SlitMode

Mean of raw values.

Value indicating whether DL-NIRSP was operated in single- or multi-slit

configuration:

Single, All

DLN__025

Int

SlitSelection

Mean of raw values.

Identifier of the slit used when DL-NIRSP is operated in single slit mode:

1,2,3,4,5

Keyword not present, if not used

DLN__026

String

SpatialStepPattern

Mode of raw values.

Selected pattern with which the FieldOfView is sampled.

Keyword not present, if not used

DLN__027

Bool

DitherMode

Mode of raw values.

Boolean indicating whether the DL-NIRSP dithering mode was activated or not. When enabled, a sub-unit field shift is used between successive completed FieldSamples: 0, 1

DLN__028

Int

NumberOfSpatialStepsX

Mode of raw values.

Value indicating the number of images in horizontal direction belonging to the scanned FieldOfView. Keyword not present, if not used

DLN__029

Float

StepCenterPositionX

Mode of raw values.

Angular position of the center position in the horizontal direction of the field scan given in units of the field scanning mirror motorized stage. Default position will be a property updated when the instrument is co-aligned with other instruments using a GOS target.

DLN__030

Float

StepSizeX

Angular step size in the horizontal direction

given in units of the field scanning mirror motorized stage. Default value will be calculated according to IFU, slits, and feed optics selection.

DLN__031

Int

CurrentSpatialStepX

Value indicating the current image position in horizontal direction belonging to the scanned FieldOfView.

1 ≤ CurrentSpatialStepX ≤ NumberOfSpatialStepsX

Keyword not present, if not used

DLN__032

Int

NumberOfSpatialStepsY

Value indicating the number of images in vertical direction belonging to the scanned FieldOfView.

Keyword not present, if not used

DLN__033

Float

StepCenterPositionY

Angular position of the center position in the vertical direction of the field scan given in units of the field scanning mirror motorized stage. Default position will be a property updated when the instrument is co-aligned with other instruments using a GOS target.

DLN__034

Float

StepSizeY

Angular step size in the vertical direction given in units of the field scanning mirror motorized stage. Default value will be calculated according to IFU, slits, and feed optics selection.

DLN__035

Int

CurrentSpatialStepY

Value indicating the current image position in vertical direction belonging to the scanned FieldOfView.

1 ≤ CurrentSpatialStepY ≤ NumberOfSpatialStepsY

Keyword not present, if not used

Key

Type

FITS Comment

Method of derivation

Description

CRSP_001

Int

ArmID

Mode of raw values.

Identifier for Cryo-NIRSP arm that generated the data: Spectro-Polarimeter, Context Viewer

CRSP_002

Float

ArmPosition

Mean of raw values.

Angular position of the arm.

CRSP_003

Float

ArmFocus

Mean of raw values.

Location of the focus stage of the arm.

CRSP_004

String

FilterID

Mode of raw values.

Unique ID of the filter in use

CRSP_005

Float

FilterWavelength

Mean of raw values.

Central wavelength of filter in use

CRSP_006

Float

FilterFWHM

Mean of raw values.

Full Width at Half Maximum spectral transmission at the current filter central wavelength in use

CRSP_007

String

PolarimeterMode

Mode of raw values.

Polarimeter Mode with which these data were acquired: Full Stokes, Stokes-I, Other(?)

CRSP_008

String

ModulatorID

Mode of raw values.

Unique identifier of the modulator.

CRSP_009

String

ModulationType

Mode of raw values.

The type of motion used by the modulator:

“discrete, continuous”

CRSP_010

String

ModulatorT0

Mode of raw values.

Reference time for the Modulator motion. Unit is TBD.

CRSP_011

Float

ModulationRate

Mean of raw values.

Rate at which states are to be acquired, in Hertz.

CRSP_012

Int

ModulationStateNumAtT0

Mean of raw values.

Integer number identifier corresponding to the particular state defined by the position of the modulator at its reference time.

CRSP_013

Int

ModulationStateAngAtT0

Mean of raw values.

Modulator angle corresponding to the modulation state at T0.

CRSP_014

Int

NumberOfStates

Mode of raw values.

Number of states to be acquired: NumberOfStates ≥ 1

CRSP_015

Int

CurrentStateNumber

Mode of raw values.

Number of the current state: 1 ≤ CurrentStateNumber ≤ NumberOfStates

CRSP_016

String

GratingID

Mode of raw values.

Unique identifier of the grating in use.

CRSP_017

Float

GratingConstant

Mean of raw values.

Grating constant.

CRSP_018

Float

GratingBlazeAngle

Mean of raw values.

Grating blaze angle.

CRSP_019

Float

GratingAngle

Mean of raw values.

Grating angle with respect to incident beam.

CRSP_020

String

SlitAssemblyID

Mode of raw values.

UniqueID of the slit assembly in use

CRSP_021

Float

SlitWidth

Mean of raw values.

Width of the slit in use

CRSP_022

Float

SlitSteppingSize

Mean of raw values.

Single step size of the slit for this observation

Keyword not present, if not used

CRSP_023

Float

SlitSteppingVelocity

Mean of raw values.

Slit move velocity for this observation [ViSP intensity mode only]. Keyword not present, if not used

CRSP_024

Int

NumberOfSpatialSteps

Mean of raw values.

Value indicating the number of images belonging to the scanned FieldOfView. Keyword not present, if not used

CRSP_025

Int

CurrentSpatialStep

Mean of raw values.

Value indicating the current image position belonging to the scanned FieldOfView. 1≤CurrentSpatialStep≤NumberOfSpatialSteps. Keyword not present, if not used

CRSP_026

String

SpatialStepPattern

Mode of raw values.

Selected pattern (scan direction) with which the FieldOfView is sampled. Keyword not present, if not used

CRSP_027

String

PickOffMirrorPosition

Mode of raw values.

Value indicates the position of the Pick Off Mirror used for this observation.

CRSP_028

String

AttenuationFilterID

Mode of raw values.

ID of Attenuation Filter in beam. Keyword not present, if not used

CRSP_029

String

ContextViewerFilterWheel1

Mode of raw values.

Value indicates the named position active in the Cryo-NIRSP Context Viewer Filterwheel 1

CRSP_030

String

ContextViewerFilterWheel1

Mode of raw values.

Value indicates the named position active in the Cryo-NIRSP Context Viewer Filterwheel 2

Key

Type

Method of derivation

Description

DSETID

String

Data Center process

Unique ID of the dataset to which the frame belongs

FRAMEVOL

Float

Data Center process

Size of the frame on disk

AVALABLE

String

Data Center process

Availability status of the frame (Available, Degraded, Lost, Removed)

PROCTYPE

String

Data Center process

Controlled value list representing the degree of processing the frame has undergone since receipt at the DKIST data center.

RRUNID

String

Data Center process

Unique ID of the Recipe Run that produced the frame

DATASUM

String

Data Center process

The value field of the DATASUM keyword shall consist of a character string that should contain the unsigned-integer value of the 32-bit ones’ complement checksum of the data records in the HDU (i.e., excluding the header records).

CHECKSUM

String

Data Center process

A 16-character ASCII string that forces the 32-bit ones’ complement checksum accumulated over the entire FITS HDU to equal negative 0 (all 32 bits equal to 1). See Appendix J of the FITS 4.0 standard.

HISTORY

String

Data Center process

The processing provenance of the data, including code modules, libraries, and associated versions. Any number of HISTORY fields may appear in the header.

Key

Type

Method of derivation

Description

ZIMAGE

String

Data Center process

This keyword must have the logical value T. It indicates that the FITS binary table extension contains a compressed image and that logically this extension should be interpreted as an image and not as a table.

ZCMPTYPE

String

Data Center process

The value field of this keyword shall contain a character string giving the name of the algorithm that must be used to decompress the image. Currently, values of GZIP 1, GZIP 2, RICE 1, PLIO 1, and HCOMPRESS 1 are reserved, and the corresponding algorithms are described in a later section of this document. The value RICE ONE is also reserved as an alias for RICE 1.

ZBITPIX

Int

Data Center process

The value field of this keyword shall contain an integer that gives the value of the BITPIX keyword in the uncompressed FITS image.

ZNAXIS

Int

Data Center process

The value field of this keyword shall contain an integer that gives the value of the NAXIS keyword in the uncompressed FITS image.

ZNAXISn

Int

Data Center process

The value field of these keywords shall contain a positive integer that gives the value of the NAXISn keywords in the uncompressed FITS image.

ZTILEn

Int

Data Center process

The value of these indexed keywords (where n ranges from 1 to ZNAXIS) shall contain a positive integer representing the number of pixels along axis n of the compression tiles. Each tile of pixels is compressed separately and stored in a row of a variable-length vector column in the binary table. The size of each image dimension (given by ZNAXISn) is not required to be an integer multiple of ZTILEn, and if it is not, then the last tile along that dimension of the image will contain fewer image pixels than the other tiles.

If the ZTILEn keywords are not present then the default ’row by row’ tiling will be assumed such that ZTILE1 = ZNAXIS1, and the value of all the other ZTILEn keywords equals 1.

The compressed image tiles are stored in the binary table in the same order that the first pixel in each tile appears in the FITS image; the tile containing the first pixel in the image appears in the first row of the table, and the tile containing the last pixel in the image appears in the last row of the binary table.

ZNAMEn

ZVALn

String

Int

Data Center process

These pairs of optional array keywords (where n is an integer index number starting with 1) supply the name and value, respectively, of any algorithm-specific parameters that are needed to compress or uncompress the image. The value of ZVALn may have any valid FITS datatype. The order of the compression parameters may be significant, and may be defined as part of the description of the specific decompression algorithm.

ZMASKCMP

String

Data Center process

Used to record the name of the image compression algorithm that was used to compress the optional null pixel data mask.

ZSIMPLE

String

Data Center process

The value field of this keyword must contain the value of the original SIMPLE keyword in the uncompressed image.

ZHECKSUM

String

Data Center process

The value field of this keyword must contain the value of the original CHECKSUM keyword in the uncompressed image.

ZDATASUM

String

Data Center process

The value field of this keyword must contain the value of the original DATASUM keyword in the uncompressed image.

Key

Type

Description

DNAXIS

Ine

The number of axes in the dataset

DNAXISn

Int

The length of the nth dataset axis

DTYPEn

String

The physical types of the axis

DPNAMEn

String

The name of the pixel axes

DWNAMEn

String

The name of the world axes

DUNITn

String

Physical unit for the nth axis of the dataset

DEAXES

Int

Extra axes not in the FITS arrays

DAAXES

Int

Number of non-unity dimensions in the array

DINDEXk

Int

index of this slice in the kth dataset axis