4.3. Meta data and FITS keywords

Here we list the entries of the more useful (for the astronomer) of the Meta data; the technical instrument and satellite Meta data are not includes. Meta data have a name, a value, and a description: the first and last are tabulated here. Some Meta data are also explained in the PDD. Some Meta data have the description "HSPOT": this is information that was entered into the AOR by the observer, rather than information gathered during the observing. The note "SLICE-INFO" indicates information related to the slicing of the product.

The table of Meta data here is not exhaustive: see the Product Description Document for a full listing. We have included here only those that are likely to be of the interest to the archive user, who in particular has little interest in understanding the more technical aspects of PACS data.

Table 4.1. Meta Data of an ObservationContext

Name Description FITS header keyword
aot astronomer observing template name AOT
aotMode aot mode, concatenation of other AOT mode Meta data AOTMODE
band filter band chosen BAND
bandUsedForRaDec band used in PhotAssignRaDec BNDRADEC
BLINDPIXELS in the flag dataset of a cube: either a T/F indicating whether this cube was created including data with the BLINDPIXELS flag, or a number indicating how many input data-points so affected were included. Ignore BLNDPIX
blue filter used for the blue camera (phot) BLUEBAND
bluWave HSPOT: blue wavelength range limit(s) BLUEWAVE
calBlock false or true for whether this product is the calBlock CALBLKID
calTreeVersion The calibration tree version used CALTREE
calVersion The calibration tree versionused CALVERS
camera/camName/camera_signature camera name, for this product CAMERA/CAMNAME/CAMSIG
chopAvoidFrom/To HSPOT entry: chop avoidance zone CHPAVFRM/CHPAVTO
chopNod HSPOT entry: true or false for chopNod mode CHOPNOD
Chopper Throw the chopper throw length CHPTHROW
chunkScanLegs chunkScanLegs used when making tod (MADMap)
ConcatenatedOBSIDS list of obsids concatenated, part of the same observation (e.g. off-source and on-source observation sequence) OBSIDLST
contains[B2A|B2B|B3A]Data T/F: at least one line or range has been observed in filter B and B2A/B2B/B3A B2ADATA/B2BDATA/B3ADATA
creationDate date this particular product was created DATE
creator the name of the software that created the product CREATOR
cusMode internal: common uplink system mode CUSMODE
dec/decNominal Dec of the observation (centre of observed field)/Dec requested DEC/DEC_NOM
decOff/decOffArcmins HSPOT entry: Dec of the requested off position for the unchopped spectroscopy mode DECOFF
decPosDegrees actual Dec of the off position in degrees DECOFFDG
density wavelength sample density requested in HSPOT WAVEDENS
description brief description of this product DESC
detRow/Col number of detector rows and columns DETROW/DETCOL
Duration of the observation in seconds
endDate/Time end date and time of the observation DATE-END/TIME-END
equinox equinox for coordinates EQUINOX
extendedSourceCorrected extended source correction applied? EXFLXCOR
faintLines faint (default) or bright line mode FAINTLIN
fileName FITS file name associated with this product FILENAME
Filter filter for this slice (for sliced products in spectroscopy pipeline)
fixedMinBinSize taken from the task wavelengthGrid when an equidistant grid is requested: the equidistant grid's bins sizes were set to a user-requested size WFIXBIN
flux[Ext|Pnt][Blu|Red] flux estimate for the source (given in HSPOT) FLUXEXT[B|R], FLUXPNT[B|R]
fluxUnit HSPOT entry: unit of the flux for lines FLXUNIT
fracMinBinSize taken from the task wavelengthGrid when an equidistant grid is requested: the equidistant grid's bins size are this fraction of the smallest bin size of the standard grid WFRACBIN
GenericAotName generic AOT name used when creating the AOR AOTNAME
glitchTreatment This parameter describes how the Second Level Deglitch Task treated the glitches GLTCHALG
gratScan internal: if true then you have unchopped (spectroscopy) mode UNCHOPD
herschelVelocityApplied was Herschel's velocity corrected for (in the pipeline)? HERVELAP
hpfRad high-pass filter radius HPFRAD
infoSpecLowSampling information flag: if True, more than 20% of spectral bins in this cube were created with fewer than 6 input datapoints (normally only those at the ends of the spectrum) ISLWSAMP
infoPhot[Blue|Red]GlitchRate/ infoSpec[Blue|Red]GlitchRate information flag: percentage of glitched datapoints for a blue photometry, red photometry, blue spectroscopy, red spectroscopy product IBPSCGLT/IRPSCGLT/ IBSSCGLT/IRSSCGLT
infoPhot[Blue|Red]NotFlaggedBad/ infoSpec[Blue|Red]NotFlaggedBad information flag: percentage of good data-points in this blue photometry, red photometry, blue spectroscopy, red spectroscopy product IBPVALPX/IRPVALPX/ IBSVALPX/IRSVALPX
infoPhot[Blue|Red]SaturationRate/ infoSpec[Blue|Red]SaturationRate information flag: saturation rate for this blue photometry, red photometry, blue spectroscopy, red spectroscopy product IBPVALPX/IRPVALPX/ IBSVALPX/IRSVALPX
infoSpecLowSampling True if more than 20% of spectral bins have less than 6 valid data-points from the PacsCube when creating the PacsRebinnedCube with the pipeline task specWaveRebin (previously was "qflag" meta datum) ISLWSAMP
instMode instrument mode (e.g. PacsLineSpec) INSTMODE
instrument instrument used (here, PACS) INSTRUME
INVALID in the flag dataset of a cube: either a T/F indicating whether this cube was created including data with the INVALID flag, or a number indicating how many input data-points so affected were included UNVALID
isInLeak does this slice contain spectroscopy data in the filter leak region (patially, fully, no), in the prime channel (that which the observed requested, i.e. not considering the free, "parallel" channel ISINLEAK
isInterlaced a mode of operation for the satellite's StarTracker ISINTERL
isOffPosition off or on position slice? ISOFFPOS
isPrime is this slice in the prime channel (that which the observer requested, not the free, "parallel" channel)? ISPRIME
instrumentConfiguration internal: instrument configuration (will be "FM"=flight model) INSTCONF
jsGalac galactic option used in JScanam JSGALAC
lcontFlux HSPOT entry: estimated continuum flux LCONTLFX
level pipeline processing Level of this product) LEVEL
lineFlux/lineWidth/lineId/lineDescription HSPOT entries: the input line fluxes, width, id, and description LINEFLX/LINEWID/LINEID/LINEINFO
lines HSPOT entry: the spectral lines chosen to observe LINES
lineStep raster line step in arcsec; meaningless for pointed observations RASSTEPL
Line 1,2.. The wavelength range(s) requested for lineScan AORs LINE1/2...
lWave HSPOT entry: line wavelength set somewhere in HSPOT LINECENT
madPixSc MADmap optional parameter: pixel scale MADPIXSC
mapGratScanOffRep HSPOT entry: for pointed or mapping observations: how often the off position is repeated (m=2 means off-on-on-off) OFFREP
mapper Mapper used to generate this product MAPPER
mapRasterAngle/ mapRasterRefFrame HSPOT entry: requested map angle wrt the instrument or the sky, and the reference frame (wrt North or wrt the boresight) RASANGLE/RASREF
mapScanAngle scan angle for the map SCANGLE
mapScanAngleRef reference frame of the scan angle SCANAREF
mapScanConstrFrom/To constraint angle of the scan angle (taken from HSPOT) SCANOFR
mapScanCrossScan separation of scan legs (taken from HSPOT) SCANCRSC
mapScanHomCoverage whether or not the map was taken in homogeneous coverage mode SCANHC
mapScanLegLength length of the scan SCANLEGL
mapScanNumLegs number of scan legs SCANLEGN
mapScanSpeed scanning speed SCANSP
mapScanSquare whether or not the map is square SCANSQ
maskDimension the number of dimensions of the masks in a PacsCube MASKDIM
max/min/meanWavelength max, min and mean wavelength in the product (usually a cube) MAXWAVE/MINWAVE/MEANWAVE
meanBinSize taken from the task wavelengthGrid when an equidistant grid is requested: the equidistant grid's bins size is the mean bin size in the standard grid WMEANBIN
minRotation minRotation used when making tod (MADMap)
naidif Solar system object NAIF identifier NAIFID
nodCycleNum nodding cycle number NODCYDEN
nodPosition nod position (A/B) that this product belongs to (mainly spectroscopy) NODPOS
NOISYPIXELS in the flag dataset of a cube: either a T/F indicating whether this cube was created including data with the NOISYPIXELS flag, or a number indicating how many input data-points so affected were included
Number of lines number of spectral lines NUMLINES
Number of Nod Cycles number of nod cycles NUMNODCY
number of rows/columns number of rows/columns on the detector DETROW/COL
NumFrames/GoodDetectors/SkyPixels/UniqueSkyPixels number of frames/good detectors in a frame without BLINDPIXELS AND BADPIXELS/sky pixels/unique sky pixels no keywords yet
numRasterLines, numRasterCol the number of raster lines and columns in the (ampping) observation NRASTLIN,NRASTCOL
object target name OBJECT
observer P.I. name OBSERVER
ObservingMode summary of all observing mode Meta data entries CUS_MODE
obsid observation identifier OBSID
obsMode HSPOT entry: observing mode, e.g. pointed or mapping OBS_MODE
obsOverhead observing overheads OBSOVHD
obsState Level processed to OBSSTATE
obsType internal OBSTYPE
odnumber operational day number ODNUMBER
odStartTime start of the operational day ODSTART
optimizeOrientation optimise orientation when making TOD (MADMap)
onOffSource on or off source: 0=not science, 1=on source, 2=off source ONOFFSRC
order grating order ORDER
orderSel HSPOT: selected blue band order (2=B2B, 3=B3A, 23=B2A) ORDERSEL
origin who/what provided these data ORIGIN
oversample the oversample parameter value in wavegrid used by pipeline task specWaveRebin OVERSMPL
oversampleSpatialGrid value of the oversample parameter used in creating the spatial grid for the drizzle task OVERS_SG
pacsSliceInfoUpdated sliced information keywords were updated? SLICEKEY
pixFrac spectroscopy: the value of the pixfrac parameter in the task drizzle (spectroscopy) or photPrject (photometry) that created this cube or map PIXFRAC
pixSize the spaxel size of this cube PIXSIZE
pmDEC/RA proper motion PMDEC/PMRA
pointingMode pointing mode keyword POINTMOD
pointSourceCorrected indicating whether this spectrum, created from a cube, has been point source corrected by one of the pipeline tasks that do this PSFLXCOR
pointStep raster step (point=column) in arcsec; meaningless for pointed observations RASSTEPC
posAngle Position angle of pointing POSANGLE
processingMode pipeline processing mode, SYSTEMATIC means "by the HSC" PROCMOD
processingParams see ConcatenatedOBSIDS PROCPARM
productNotes text describing the product. e.g. HPSFITB for spectroscopy blue fit ramps PRODNOTE
proposal name given to the programme when proposal was submitted PROPOSAL
qflag_XXX and infoXXX quality control flags, where "XXX" is replaced by various initials: see their Meta data entries for a description of each XXX; before SPG 13 all PACS products had qflag_ entries related to data issues, but from SPG 13 onwards these have been moved to "info" flags (see entry above for these) various: see the "qualitySummary" in the ObservationContext and documentation on the DpKnowIssue HSC web-page for the affected observations
ra/raNominal RA of the observation (centre of observed field)/RA requested RA/RA_NOM
raDeSys RA, Dec coordinate reference frame RADESYS
radialVelocity spacecraft velocity along the line of sight to the target VFRAME
rangeHigh1/2../rangeLow1/2/.. high or low wavelength end of the spectral range in this produce RANGEHI1/2/.. RANGELO1/2..
rangeId/rangeSPOT HSPOT: information about the wavelength range for rangeScan AORs RANGEID/RANGDESC
raOff HSPOT value: requested RA off position RAOFF
rasterId raster line, column for this slice RASID
RAWSATURATION in the flag dataset of a cube: either a T/F indicating whether this cube was created including data with the RAWSATURATION flag, or a number indicating how many input data-points so affected were included RSATWARN
redshiftType/Value HSPOT value: the redshift given by the astronomer REDSHFT/REDSHFTV
repetition grating scan repetition index for this slice (UPSCAN/DOWNSCAN repeats) REPEATS
repeatLine, repeatRange how many times the line or range was repeated LINEREP/RANGEREP
RemovedSetTime number of removed Frames due to setTime command RMTIMSET
SATURATIONWARNING depending on which product it is related to, this is either T/F indicating whether saturated data were included when creating this cube, or a number indicating how many input data (when creating this product) were saturated SATWARN
scale pixel scale used when making TOD (MADMap)
slewTime time of start of slew to the target SLEWTIME
sliceNumber the slice number of this product (which will therefore be in or was in a context) SLICENUM
solarAspecAngle[Mean|Rms] the mean/rms of the solar aspect angle (angle of instrument wrt the sun SAAMEAN/SAARMS
source HSPOT entry: type of observation, e.g. point(ed observation) or large (mapping observation) for spectroscopy. Values are point(ed), dithered (a mode that did not last long into the mission), or large (aka mapping) SOURCE
spaxelRow/Column/Ra/Dec the assorted spaxel coordinates that this spectrum was taken from SPAXROW/SPAXCOL/ SPAXRA/SPAXDEC
spec_[blue|red]_FailedSPUBuffer internal: percentage of failed SPU (signal processing unit) (anomaly 70) FAILSPUR/FAILSPUB
startDate/Time start of observation DATE-OBS/TIME-OBS
Starting time start of observation in a friendly format OBSSTART
telescope obviously: Herschel! TELESCOP
throw chopper throw (spectroscopy) CHPTHROW
TodFilename filename of temporary TOD file
type product type, e.g. HPSFITB for spectroscopy blue fit ramps TYPE
uniFiltS/StImg/DWgls/GWgls optional parameters of the UNIMAP processing UNIFILTS/UNISTIMG/ UNIDWGLS/UNIGWGLS
upsample the upsample parameter value in wavegrid used by pipeline task specWaveRebin UPSMPL
upsampleSpatialGrid value of the upsample parameter used in creating the spatial grid for the drizzle task UPSMP_SG
userNODCycles HSPOT value: number of nod cycles requested NODCYREP
UNVALID ignore UNVALID
velocityDefinition which model was used to compute Herschel's radial velocity VELDEF
verbose internal VERBOSE
wavelengthGridEquidistant taken from the task wavelengthGrid and set to True when an equidistant grid was requested WGRIDEQ
widthUnit HSPOT value: line width unit WID_UNIT

To query the meta data on the command line you can modify these examples:

# From an ObservationContext called obs
# - print all the meta data, so you know what are there
print obs.meta
# - print the meta data entry for "obsid" 
print obs.meta["obsid"]
# - print only the value of the "obsid" (which is held as a long)
print obs.meta["obsid"].long
print obs.meta["obsid"].value
# - what was the requested RA and Dec 
print obs.meta["raNominal"]
print obs.meta["raNominal"].double, obs.meta["decNominal"].double

# For a sliced product, access the meta data in this way:
slicedFrames = obs4.level1.fitted.red.product
print slicedFrame.meta
frames = slicedFrames.get(0) # the first Frames in slicedFrames 
print frames.meta