D Mapping

The following tables define the mapping (in version 5.3 of the JCMT storage task) from item names that will be found in the data files (the “NRAO” name) to the JCMT name. Also included is the nominal FITS header equivalent, emphasis indicating a JCMT-specific variant, and a text description of the field.


Table 1: Mapping of GSD names to FITS equivalents.






NRAO JCMT FITS

Description









CELL_V2Y CELL_V2Y YPOSANG

Position angle of cell y axis (CCW)

UAZ SDIS(36) UXPNT

User az correction

UEL SDIS(37) UYPNT

User el correction

C1BKE BACKEND BACKEND

Name of the backend

C1BTYP BE_TYPE BACKTYPE

Type of backend

C1DP DATA_PRECISION PRECIS

Precision of the data from the backend

C1FTYP FE_TYPE FRONTYPE

Type of frontend

C1HGT TEL_HEIGHT HEIGHT

Height of telescope above sea level

C1IFS IF_DEVICE IFDEVICE

Name of the IF device

C1LAT TEL_LATITUDE LATITUDE

Geodetic latitude of telescope (North +ve)

C1LONG TEL_LONGITUDE LONGITUD

Geographical longitude of telescope (West +ve)

C1OBS PROJECT_OBS_1 OBSID

Name of the primary observer

C1ONA PROJECT_OBS_1 OBSERVER

Name of the primary observer

C1ONA1 PROJECT_OBS_2 OBSERVER

Name of the support scientist

C1ONA2 PROJECT_OBS_3 OPERATOR

Name of the telescope operator

C1PID PROJECT PROJID

Identifies the observing program

C1RCV FRONTEND FRONTEND

Name of the frontend

C1SNA1 CENTRE_NAME_1 OBJECT

Source name part 1

C1SNA2 CENTRE_NAME_2 OBJECT2

Source name part 2 or altern. name

C1SNO NOBS SCAN

Observation number

C1STC OBS_TYPE OBSTYPE

Type of observation

C1TEL TEL_NAME TELESCOP

Telescope name

C2FL DY FOCUSL

Secondary mirror y displacement from nominal at observation start

C2FR DZ FOCUSR

Secondary mirror z displacement from nominal at observation start

C2FV DX FOCUSV

Secondary mirror x displacement from nominal at observation start

C2ORI SECONDARY_ORI ORIENT

Rotation or polarization angle orientation of the frontend/reflector

C2PC1 TEL_PC_LAN PTCON1

Angle by which lower axis is north of ideal

C2PC2 TEL_PC_LAE PTCON2

Angle by which lower axis is east of ideal

C2PC3 TEL_PC_UANP PTCON3

Angle by which upper axis is not perpendicular to lower

C2PC4 TEL_PC_BNP PTCON4

Angle by which beam is not perpendicular to upper axis

C2XPC TEL_PC_LAZ AXPOINT

Azimuth/RA enc.zero; enc.reading = az + pc_laz

C2YPC TEL_PC_UAZ AYPOINT

Altitude/DEC enc.zero; enc.reading = az + pc_uaz

C3BEFENULO BES_FE_NULO BEFENULO

Copy of frontend LO frequency per backend section

C3BEFESB BES_FE_SB_SIGN BEFESB

Copy of frontend sideband sign per backend section

C3BEINCON BE_IN_CONN BEINCON

IF output channels connected to BE input channels

C3BESCONN BES_CONN BESCON

BE input channels connected to this section

C3BESSPEC BES_SPECTRUM BESSPEC

Subsystem nr to which each backend section belongs.

C3BETOTIF BES_TOT_IF BETOTIF

Total IF per backend section

C3CAL OBS_CALIBRATION OBSCAL

Calibration observation?

C3CEN OBS_CENTRE OBSCEN

Centre moves between scans?

C3CL CYCLE_TIME CYCLLEN

Duration of each cycle

C3CONFIGNR DAS_CONF_NR CONFIG

Backend configuration

C3DASCALSRC DAS_CAL_SOURCE CALSRC

DAS calibration source for backend calibration (POWER or DATA)

C3DASOUTPUT DAS_OUTPUT OUTPUT

Description of output in DAS DATA (SPECTRUM, T_REC, T_SYS, etc.)

C3DASSHFTFRAC DAS_SHIFT_FRAC SHFTFRAC

DAS calibration source for backend calibration (POWER or DATA)

C3DAT OBS_UT1D UTDATE

UT1 date of observation

C3FLY OBS_CONTINUOUS OBSFLY

Data taken on the fly or in discrete mode?

C3FOCUS OBS_FOCUS OBSFOCUS

Focus observation?

C3INTT INTGRN_TIME INTGR

Scan integration time

C3LSPC NO_BES_O_CH NOBESDCH

Number of channels per backend section

C3LST OBS_LST LST

Local sidereal time at the start of the observation

C3MAP OBS_MAP OBSMAP

Map observation?

C3MXP NO_SCAN_PNTS NOSCNPTS

Maximum number of map points done in a phase

C3NCH NO_BE_O_CH NOBEOCH

No.backend output channels

C3NCI NO_CYCLES NOCYCLES

Maximum number of cycles in the scan

C3NCP NO_CYCLE_PNTS NOCYCPTS

Total number of xy positions observed during a cycle

C3NCYCLE NCYCLE NCYCLE

Number of cycles done in the scan

C3NFOC NO_FE_O_CH NOFCHAN

NO_FE_O_CH:No. of frontend output channels

C3NIS NO_SCANS NOSCANS

Number of scans

C3NLOOPS NO_SCANS NSCANS

Number of scans per observation commanded at observation start

C3NMAP NO_MAP_PNTS NOPTS

Number of map points

C3NOIFPBES NO_IF_PER_BES NOIFPBES

Number of IF inputs to each section (2 for correlator, 1 for AOS)

C3NO_SCAN_VARS1 NO_SCAN_VARS1 NOSCNVR1

Number of scan table 1 variables

C3NO_SCAN_VARS2 NO_SCAN_VARS2 NOSCNVR2

Number of scan table 2 variables

C3NPP NO_MAP_DIMS NOMAPDIM

Number of dimension in the map table

C3NRC NRC NORCHAN

NO_BE_I_CH:No.backend input channels

C3NRS NO_BES NORSECT

Number of backend sections

C3NSAMPLE NSCAN NSCAN

Number of scans done

C3NSV NO_PHASE_VARS NOSWVAR

Number of phase table variables

C3OVERLAP BES_OVERLAP OVERLAP

Subband overlap

C3PPC NO_PHASES NOPHASE

Number of phases per cycle

C3SRT SCAN_TIME SAMPRAT

Total time of scan (=total integration time if OBS_CONTINUOUS = .FALSE.)

C3UT OBS_UT1H UT

UT1 hour of observation

C3UT1C OBS_UT1C UT1C

UT1-UTC correction interpolated from time service telex (in days)

C4AMPL_EW AMPL_EW CHOPAZ

Secondary mirror chopping amplitude parallel to lower axis

C4AMPL_NS AMPL_NS CHOPEL

Secondary mirror chopping amplitude parallel to upper axis

C4AXY CELL_X2Y XYANGLE

Angle between cell y axis and x-axis (CCW)

C4AZ CENTRE_AZ AZ

Azimuth at observation date

C4AZERR SDIS(7) XPOINT

DAZ:Net Az offset at start (inc.tracker ball setting and user correction)

C4CECO CENTRE_CODE COORDCD2

centre coords. AZ= 1;EQ=3;RD=4;RB=6;RJ=7;GA=8

C4CSC CENTRE_COORDS COORDCD

Character code of commanded centre or source coordinate system

C4DAZ DAZ_SM XPOINT

Telescope lower axis correction for secondary mirror XYZ

C4DECDATE CENTRE_DEC DECDATE

Declination of date

C4DEL DEL_SM YPOINT

Telescope upper axis correction for secondary mirror XYZ

C4DO1 CELL_X DESORG1

Cell x dimension; descriptive origin item 1

C4DO2 CELL_Y DESORG2

Cell y dimension; descriptive origin item 2

C4DO3 CELL_V2X DESORG3

Angle by which the cell x axis is oriented with respect to local vertical

C4EDC CENTRE_DEC EPOCDEC

Declination of date

C4EDEC CENTRE_DEC1950 EPOCDEC

Declination of source for EPOCH

C4EDEC2000 CENTRE_DEC2000 DECJ2000

Declination J2000

C4EL CENTRE_EL EL

Elevation at observation date

C4ELERR SDIS(8) YPOINT

DEL:Net El offset at start (inc.tracker ball setting and user correction)

C4EPH CENTRE_EPOCH EPOCH

Date of the RA/DEC coordinates (1950)

C4EPT EPOCH_TYPE EPOCHTYP

Type of epoch, JULIAN, BESSELIAN or APPARENT

C4ERA CENTRE_RA1950 EPOCRA

Right ascension of source for EPOCH

C4EW_ENCODER AMPL_E_SET EW_ENCOD

Secondary mirror ew encoder value

C4EW_SCALE EW_AMPL_SCALE EW_SCALE

Secondary mirror ew chop scale

C4FRQ FREQUENCY CHOPFREQ

Secondary mirror chopping period

C4FUN WAVEFORM WAVEFORM

Secondary mirror chopping waveform

C4GB CENTRE_GB GALLAT

Galactic latitude

C4GL CENTRE_GL GALLONG

Galactic longitude

C4LSC CELL_COORDS FRAME

Char. code for local x-y coord.system

C4MCF CENTRE_MOVING CENMOVE

Centre moving flag (solar system object)

C4MOCO TEL_COORDS MOUNTING

Mounting of telescope; defined as LOWER/UPPER axes, e.g; AZ/ALT

C4NS_ENCODER AMPL_N_SET NS_ENCOD

Secondary mirror ns encoder value

C4NS_SCALE NS_AMPL_SCALE NS_SCALE

Secondary mirror ns chop scale

C4ODCO CELL_UNIT MAPUNIT

Units of cell and mapping coordinates;offset definition code

C4OFFS_EW OFFS_EW EWTILT

Secondary mirror offset parallel to lower axis (East-West Tilt)

C4OFFS_NS OFFS_NS NSTILT

Secondary mirror offset parallel to upper axis (North-South Tilt)

C4PER PERIOD CHOPTIME

Secondary mirror chopping period

C4POSANG POSANG CHOPDIRN

Secondary mirror chop position angle

C4RA2000 CENTRE_RA2000 RAJ2000

Right ascension J2000

C4RADATE CENTRE_RA RADATE

Right Ascension of date

C4RX REFERENCE_X XREF

Reference x position (JCMT cells wrt to centre; NRAO abs. degrees)

C4RY REFERENCE_Y YREF

Reference y position (JCMT cells wrt to centre; NRAO abs. degrees)

C4SM CHOPPING CHOPPING

Secondary mirror is chopping

C4SMCO COORDS CHOPCOOR

Secondary mirror chopping coordinate system

C4SX CENTRE_OFFSET_X XSOURCE

Commanded x centre position (JCMT cells wrt to centre; NRAO abs. degrees)

C4SY CENTRE_OFFSET_Y YSOURCE

Commanded y centre position (JCMT cells wrt to centre; NRAO abs. degrees)

C4THROW THROW CHOPTHRW

Secondary mirror chop throw

C4X X AFOCUSV

Secondary mirror absolute X position at observation start

C4Y Y AFOCUSH

Secondary mirror absolute Y position at observation start

C4Z Z AFOCUSR

Secondary mirror absolute Z position at observation start

C5AT TAMB TAMB

Ambient temperature

C5DP DEW_POINT DEW_PT

Mean atmospheric dew point

C5IR REF_INDEX REFRAC

Mean atmospheric refractive index (alternative)

C5IR1 TEL_REFR_A REFRAC1

Refraction constant A (see MTIN026)

C5IR2 TEL_REFR_B REFRAC2

Refraction constant B (see MTIN026)

C5IR3 TEL_REFR_C REFRAC3

Refraction constant C (see MTIN026)

C5MM VAP_PRESSURE MMH2O

Mean atmospheric vapour pressure

C5PRS PAMB PRESSURE

Mean atmospheric pressure

C5RH HAMB HUMIDITY

Mean atmospheric relative humidity

C6CYCLREV CYCLE_REVERSAL CYCLREV

Cycle reversal flag

C6DX CELL_X DELTAX

Cell x dim,; descriptive origin item 1

C6DY CELL_Y DELTAY

Cell y dimension; descriptive origin item 2

C6FC CELL_CODE FRAME2

Local x-y AZ= 1;EQ=3;RD=4;RB=6;RJ=7;GA=8

C6MODE SWITCH_MODE SWMODE

Observation mode

C6MSA CELL_V2X SCANANG

Scanning angle - angle from local vertical to x axis measured CW

C6NP NCYCLE_PNTS NCYCPTS

Number of sky points completed in the observation

C6REV SCAN_REVERSAL REVERSAL

Map rows scanned in alternate directions?

C6SD OBS_DIRECTION DIRECTN

Map rows are in X (horizontal) or Y(vertical) direction

C6ST OBS_TYPE OBSMODE

Type of observation

C6XGC X_MAP_START XCELL0

X coordinate of the first map point

C6XNP NO_X_MAP_PNTS NOXPTS

X map dimension; number of points in the x-direction

C6XPOS X_MAP_POSITIVE XSIGN

In first row x increases (TRUE) or decreases (FALSE)

C6YGC Y_MAP_START YCELL0

Y coordinate of the first map point

C6YNP NO_Y_MAP_PNTS NOYPTS

Y map dimension; number of points in the y-direction

C6YPOS Y_MAP_POSITIVE YSIGN

In first row y increases (TRUE) or decreases (FALSE)

C7AP APERTURE APERTURE

Aperture

C7BCV BAD_CHANNEL BADCHV

Bad channel value

C7CAL CAL_TYPE TYPECAL

Calibration type (standard or direct, chopperwheel)

C7FIL FILTER FILTER

Filter

C7HP FWHM

FWHM of the beam profile (mean)

C7NIF NO_IF_CH NOIFCHAN

Number of IF channels

C7OSN OBS_REF_SCAN OFFSCAN

Calibration observation number (in which a standard was observed)

C7PHASE PHASE PHASE

Lockin phase

C7SEEING SAO_SEEING SEEING

Seeing at JCMT

C7SEETIME SAO_YYMMDDHHMM SEETIME

SAO seeing time (YYMMDDHHMM)

C7SNSTVTY SENSITIVITY SNSTVTY

Lockin sensitivity in scale range units

C7SNTVTYRG RANGE SNTVTYRG

Sensitivity range of lockin

C7SZVRAD SZVRAD SZVRAD

Number of elements of vradial array

C7TAU225 CSO_TAU TAU225

CSO tau at 225GHz

C7TAURMS CSO_TAU_RMS TAURMS

CSO tau rms

C7TAUTIME CSO_YYMMDDHHMM TAUTIME

CSO tau time (YYMMDDHHMM)

C7TIMECNST TIME_CONSTANT TIMECNST

Lockin time constant

C7VC VEL_COR RVSYS

Velocity correction

C7VR VELOCITY VELOCITY

Radial velocity of the source

C7VRD VEL_DEF VELDEF

Velocity definition code; method of computing the velocity

C7VREF VEL_REF VELREF

Velocity reference code; reference point for telescope & source velocity

C8AAE APERTURE_EFF APPEFF

Ratio total power observed/incident on the telescope

C8ABE BEAM_EFF BEAMEFF

Fraction of beam in diffraction limited main beam

C8EF ETAFSS ETAFSS

Forward spillover and scattering efficiency

C8EL ETAL ETAL

Rear spillover and scattering efficiency

C8GN ANTENNA_GAIN ANTGAIN

Antenna gain

C9OT TEL_TOLERANCE OBSTOL

Observing tolerance

C11PHA PHASE_TABLE PHASTB

Phase table: switching scheme dependent

C11VD PHASE_VARS VARDES

Names of the cols. of phase table

C12ALPHA BES_ALPHA ALPHA

Ratio of signal sideband to image sideband sky transmission

C12BM BES_BITMODE BM

Correlation bit mode

C12BW BANDWIDTH BW

Bandwidth

C12CAL DATA_UNITS DATAUNIT

Units of spectrum data

C12CALTASK BE_CAL_TASK CALTASK

Calibration instrument used (FE, BE, or USER)

C12CALTYPE BE_CAL_TYPE CALTYPE

Type of calibration (THREELOADS or TWOLOADS)

C12CF FE_NUOBS OBSFREQ

Centre frequency

C12CM BES_CORR_MODE CM

Correlation function mode

C12CT TCAL TCAL

Calibration temperature

C12ETASKY BES_ETA_SKY ETA_SKY

Sky transmission from last calibration

C12ETASKYIM BES_ETA_SKY_IM ETA_SKY_

Frontend-derived sky transmission

C12ETATEL BES_ETA_TEL ETA_TEL

Telescope transmission

C12FR DELTANU FREQRES

Frequency resolution [MHz]

C12GAINS GAIN GAINS

Gains

C12GNORM G_NORM GNORM

Data normalisation factor

C12GREC GREC

Raw data units per Kelvin

C12GS BES_G_S G_S

Normalizes signal sideband gain

C12INFREQ BE_NUIN INFREQ

BE input frequencies [GHz]

C12NOI NOISE NOISE

Noise value

C12REDMODE BE_RED_MODE REDMODE

Way of calibrating the data (RATIO or DIFFERENCE)

C12RF FE_NUREST RESTFREQ

Rest frequency

C12RST TSYS_OFF RTSYS

Reference system temperature

C12RT TREC TRX

Receiver temperature

C12SBRAT BE_SB_RATIO SBRATIO

Sideband ratio

C12SCAN_TABLE_1 SCAN_TABLE1 SCANTAB1

Begin scan table

C12SCAN_TABLE_2 SCAN_TABLE2 SCANTAB2

End scan table

C12SCAN_VARS1 SCAN_VARS1 SCANVRS1

Names of the cols. of scan table1

C12SCAN_VARS2 SCAN_VARS2 SCANVRS2

Names of the cols. of scan table2

C12SST TSYS_ON STSYS

Source system temperature

C12TAMB T_HOT THOT

Ambient load temperature

C12TASKY BES_TA_SKY TA_SKY

Ratio of signal sideband to image sideband sky transmission

C12TCOLD T_COLD TCOLD

Cold load temperature

C12TSKY TSKY TSKY

Sky temperature at last calibration

C12TSKYIM BES_T_SKY_IM T_SKY_IM

Frontend-derived Tsky, image sideband

C12TSYSIM BES_T_SYS_IM T_SYS_IM

Frontend-derived Tsys, image sideband

C12TTEL TTEL TTEL

Telescope temp. from last skydip

C12VCOLD IF_V_COLD VCOLD

C12VDEF VEL_DEFN

Velocity definition code - radio, optical, or relativistic

C12VHOT IF_V_HOT VHOT

C12VREF VEL_REF

Velocity frame of reference - LSR, Bary-, Helio-, or Geo- centric

C12VSKY IF_V_SKY VSKY

C12WO H2O_OPACITY TAUH2O

Water opacity

C13DAT DATA SPECT

Reduced data

C13ERR ERROR TRMS

Standard error

C13RAW_ERROR DATA_ERROR RAWERROR

C13RAW_ERROR_OP RAW_ERROR_OP RAWERROR

Raw (out of phase) error also to be stored at end scan

C13RESP RESP RESP

array of responsivities

C13SPV SAMPLES RAWSPECT

C13SPV_OP SAMPLES_OP RAWSPECT

Raw out of phase data samples in each phase

C13STD STDEV STDSPECT

Phase data standard deviation

C14PHIST MAP_TABLE MAPTABLE

List of xy offsets for each scan

C90T TEL_TOLERANCE OBSTOL

Observing tolerance