EPRV PRIMARY FITS Header

Noteable Extensions & Header Keywords

The Receipt Extension

The EPRV data standard makes use of a receipt extension, inspired by the KPF data reduction pipeline. The receipt is structured as a pandas.Dateframe table and keeps track of the data process history, so that the information stored by this instance can be reproduced from the original data. Each row of the receipt should capture an individual data processing event.

Translators that generate/modify the content of an EPRV standard data product are expected to also write to the receipt. The receipt is inherited from lower order data products (e.g., L2) to higher order data products (e.g., L3) to preserve the data processing history.

Three string inputs are required: name, any relevant parameters, and a status. The receipt will also automatically fill in additional information, such as the time of execution, code release version, current branch, ect.

The Config Extension

This extension contains a two-column dataframe that stores each line of the input configuration file.

This file is based on the configuration language that the Python ConfigPaser class implements for Python programs. The syntax of the configuration language primarily consists of key = value statements and # comments (or ; comments).

The creation of the key/value pairs, in general, follows the convention as those provided by the ConfigParser classs. As used in the KPF and NEID Pipelines, the keys consists of alphanumerics and underscores (e.g. KPFPIPE_TEST_DATA) while the value is in the form of a string, a number, a boolean, or a list.

PRIMARY Header Keywords

MULTIPLICITY : Keyword in the PRIMARY extension that indicates whether or not an extension can be duplicated to have multiple HDUs based on, e.g., the number of traces.

REQUIRED : Keyword in the PRIMARY extension that indicates whether or not an extension must be present and meaningfully populated in the FITS file in order for the file to be compliant with the EPRV Data Standard.

INSTERA : Tag for the “instrument era” used to track permanent changes to instrument (e.g., 1.1.2). Major changes that result in RV offset are recorded in the first numeral space. Small but permanent changes, (changes in the calibration light sources, etc) that don’t necessarily introduce RV offsets but do represent an ongoing status change in the instrument, are recorded in the second numeral. Anything that could impact the calibration or science outputs goes here. Even smaller changes, or things that you only recognize retrospectively, are recorded in the third numeral.

Note: Each team will place a csv file into the config directory with 1 line per era that has the start and end dates of each timespan. If this file is already maintained elsewhere by the instrument team then link to that instead so the file doesn’t need to be maintained in multiple places.

Keyword Table

Keyword	Description	Units	DataType	Example Value	Default	Required	Comments
INSTRUME	Instrument name	N/A	String	NEID or HARPS	UNKNOWN	True
ORGANIZA	Organization the data belongs to, for licensing purposes	N/A	String	ESO or CC-0	CC-0	False
ORIGIN	Entity that created this file	N/A	String	ESO or NOIRLab	UNKNOWN	False
DATALVL	Data Product Base Level	N/A	String	L2 or L3	UNKNOWN	True
OBSERVER	Observer	N/A	String	Bender	UNKNOWN	True
PROGRAM	Observing program name	N/A	String	Bender01	UNKNOWN	False	For data filtering and attribution; default to Unknown if it does not exist
PINAME	Program PI Name	N/A	String	Bender	UNKNOWN	False	For data filtering and attribution; default to Unknown if it does not exist
OBSTYPE	Observation type	N/A	String	Sci or Eng	UNKNOWN	True
OBSMODE	Observing mode	N/A	String	HR or HE		False
READMODE	Readout Mode	N/A	String	Fast; Slow; UTR; FowlerN; or CDS		False
BINNING	Binning Mode	N/A	String	1x1 or 2x2	UNKNOWN	True
NUMTRACE	Iterator for Number of Object related keywords	N/A	UInt	1	UNDEFINED	True
NUMORDER	Number of Orders	N/A	Uint	172	UNDEFINED	True
OBJECT	Primary Object Name	N/A	String	HD 10700	UNKNOWN	True	For multi-object observing this corresponds to center of field object
ALIASES	user defined name(s) for the object, ; separated	N/A	String	Tau Ceti; My Favorite Star		False
FILENAME	Name of the FITS file	N/A	String	InstL#_YYYYMMDDThhmmss.fits	UNKNOWN	True
DATE	Last modification date/time of this file	UTC	String	2018-04-26T15:53:13.456	UNKNOWN	True
DATE-OBS	Date/time at start of exposure	UTC	String	2018-04-26T15:53:13.456	UNKNOWN	True
JD_UTC	Julian date of DATE-OBS	day	Double	2450000	UNDEFINED	True
EXPTIME	Exposure time	s	Float	29.43664	UNDEFINED	True
TRACE1 … TRACE#	Type of object in trace 1 to #	N/A	String	SCI or CAL or SKY	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #
CLSRC1 … CLSRC#	Name of calibration source in trace 1 to # [if used]	N/A	String	LFC or Etalon or UNe	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #
CSRC1 … CSRC#	Catalog source for object in trace 1 to #	N/A	String	GaiaDR2	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #; Should define hierarchy of catalogs
CID1 … CID#	Catalog name/designation for object in trace 1 to #	N/A	String	DR2 NNNNNNNNNNNNNNNNNNN	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #
CRA1 … CRA#	Catalog right ascension for object in trace 1 to #	sexagesimal	String	HH:MM:SS.sss	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #
CDEC1 … CDEC#	Catalog declination for object in trace 1 to #	sexagesimal	String	DD.mm.ss.sss	UNKNOWN	True	Can be expanded to multiple keywords indexed 1 to #
CEQNX1 … CEQNX#	Catalog equinox for object in trace 1 to #	yr	Float	2000	UNDEFINED	True	Can be expanded to multiple keywords indexed 1 to #
CEPCH1 … CEPCH#	Catalog epoch for object in trace 1 to #	yr	Float	2015.5	UNDEFINED	True	Can be expanded to multiple keywords indexed 1 to #
CRV1 … CRV#	Catalog Systemic RV for for object in trace 1 to #	km/s	Float	45.654	UNDEFINED	True	Can be expanded to multiple keywords indexed 1 to #
CPLX1 … CPLX#	Catalog parallax for object in trace 1 to #	mas	Float	20.45		False	Can be expanded to multiple keywords indexed 1 to #
CPMR1 … CPMR#	Catalog proper motion RA for object in trace 1 to #	arcsec/yr	Float	0.0345		False	Can be expanded to multiple keywords indexed 1 to #
CPMD1 … CPMD#	Catalog proper motion DEC for object in trace 1 to #	arcsec/yr	Float	0.345		False	Can be expanded to multiple keywords indexed 1 to #
CZ1 … CZ#	Catalog Z for for object in trace 1 to #	N/A	Float	0.00000454		False	Can be expanded to multiple keywords indexed 1 to #
CCLRN1 … CCLRN#	Catalog color 1 - color 2 name for object in trace 1 to #	N/A	String	Gaia B-R		False	Can be expanded to multiple keywords indexed 1 to #
CCLR1 … CCLR#	Catalog color 1 - color 2 for object in trace 1 to #	mag	Float	0.47		False	Can be expanded to multiple keywords indexed 1 to #
OBSERVAT	Observatory name	N/A	String	KPNO	UNKNOWN	True
TELESCOP	Telescope name	N/A	String	ESO-VLT-U1234 WIYN or NEIDSOLARFEED	UNKNOWN	True	For solar observations - if solarfeed has its own name use that otherwise use an instrument + solarfeed type entry
NUMTEL	Number of telescopes used in the observation	N/A	UInt	1	UNDEFINED	True
TELEID1 … TELEID#	Labels for telescopes as indexed in TCS keywords	N/A	String	ESO-VLT-U1	UNKNOWN	True
GEOSYS	Coordinate system for observatory / telesccope location	N/A	String	GRS80	UNKNOWN	True
OBSLON	Longitude used for barycentric correction	deg	Float	-111.600562	UNDEFINED	True	Recommend 6 decimal places which is ~1m accuracy
OBSLAT	Latitude used for barycentric correction	deg	Float	31.958092	UNDEFINED	True	Recommend 6 decimal places which is ~1m accuracy
OBSALT	Altitude used for barycentric correction	meters	Float	2091	UNDEFINED	True	Recommend 6 decimal places which is ~1m accuracy
OBSGEO-X	Cartesian Coordinate X used for barycentric correction	meters	Float	5327395.964		False	geocentric Cartesian triple incarnation of the traditional lat/lon/alt position on earth
OBSGEO-Y	Cartesian Coordinate Y used for barycentric correction	meters	Float	-1719170.488		False	geocentric Cartesian triple incarnation of the traditional lat/lon/alt position on earth
OBSGEO-Z	Cartesian Coordinate Z used for barycentric correction	meters	Float	3051490.766		False	geocentric Cartesian triple incarnation of the traditional lat/lon/alt position on earth
ISSOLAR	Boolean to indicate if observation is of the sun	N/A	Boolean	FALSE	UNKNOWN	True
SEEING	Seeing at beginning of exposure	arcsec	Float	1.2		False
AIRMASS	Airmass at center field at beginning of exposure	secZ	Float	1.3		False
TTIME	TCS-data date/time	UTC	String	2018-04-26T15:53:13		False
TEQNX	TCS equinox	yr	String	J2000		False
TEPCH	TCS epoch	yr	String	J2000		False
TLST1 … TLST#	TCS local sidereal time for telescope 1 to #	sexagesimal	String	14:23:43		False	Can be expanded to multiple keywords indexed 1 to #
TRA1 … TRA#	TCS RA for telescope 1 to #	sexagesimal	String	13:43:42.3456		False	Can be expanded to multiple keywords indexed 1 to #
TDEC1 … TDEC#	TCS DEC for telescope 1 to #	sexagesimal	String	-13:34:12.7787		False	Can be expanded to multiple keywords indexed 1 to #
TEL1 … TEL#	TCS elevation angle for telescope 1 to #	deg	Float	43.5		False	Can be expanded to multiple keywords indexed 1 to #
TZA1 … TZA#	TCS zenith angle for telescope 1 to #	deg	Float	35.5435		False	Can be expanded to multiple keywords indexed 1 to #
TAZ1 … TAZ#	TCS azimuth angle for telescope 1 to #	deg	Float	124.3		False	Can be expanded to multiple keywords indexed 1 to #
THA1 … THA#	TCS hour angle for telescope 1 to #	sexagesimal	String	-2:34:43.3455		False	Can be expanded to multiple keywords indexed 1 to #
PARST1 … PARST#	Parallactic angle at exposure start for telescope 1 to #	deg	Float	175.2		False	Can be expanded to multiple keywords indexed 1 to #
PAREND1 … PAREND#	Parallactic angle at exposure end for telescope 1 to #	deg	Float	180.7		False	Can be expanded to multiple keywords indexed 1 to #
ROTANG	Rotator angle	deg	Float	80.3		False
SUNEL	Sun Elevation Angle	deg	Float	-18.5		False
MOONANG	Target-Moon Angle	deg	Float	34.56		False
MOONEL	Moon Elevation Angle	deg	Float	26.8		False
MOONILLU	Moon illumination	%	Float	23.4		False
MOONRV	RV of reflected sunlight off moon	km/s	Float	1.3		False
M1TMP	Primary mirror temperature	deg C	Float	10.0		False
M1TMPT	M1TMP timestamp	UTC	String	2024-02-20T03:31:33		False
INHUM	relative humidity inside dome	%	Float	56.6		False
INHUMT	INHUM timestamp	UTC	String	2024-02-20T03:31:33		False
OUTTMP	Outside temperature	deg C	Float	0.0		False
OUTTMPT	OUTTMP timestamp	UTC	String	2024-02-20T03:31:33		False
OUTHUM	Outside relative humidity	%	Float	56.6		False
OUTHUMT	OUTHUM timestamp	UTC	String	2024-02-20T03:31:33		False
OUTPRES	Outdoor Atmospheric Pressure	kPa	Float	80.0		False
OUTPREST	OUTPRES timestamp	UTC	String	2024-02-20T03:31:33		False
ENVWINDS	Wind speed	m/s	Float	23.4		False	Details are obs specific and not uniform; best effort as available from the observatory
ENVWINDD	Wind direction	angle	Float	133.5		False	Details on where wind is measured (position of weather station) should be captured in documentation
DRPTAG	RV DRP version	N/A	String	v1.1.0	UNKNOWN	True
EPRVTAG	Version of EPRV standard applied	N/A	String	v1.1.0	UNKNOWN	True
VOCLASS	Version of EPRV standard applied	N/A	String	EPRVSTANDARDv1.1.0	UNKNOWN	True
DRPHASH	Git commit hash	N/A	String	a1b2c3d4e5f67890abcdef1234567890abcdef12		False
INSTERA	Tag to track permanent changes to instrument	N/A	String	v2.3.0	UNKNOWN	True
EXTRACT	Type of 1D extraction	N/A	String	sum or flatrelative or optimal		False
EXSNR1 … EXSNR#	Extracted signal-to-noise at EXSNRW1 to EXSNRW#	SNR/1-D pixel	FLOAT	245.35		False	Can be expanded to multiple keywords indexed 1 to #; Meant to be a set of useful SNR checks, not one for every order
EXSNRW1 … EXSNRW#	Wavelength at which EXTSNR1 to EXTSNR# is measured	Angstroms	FLOAT	5530		False	Can be expanded to multiple keywords indexed 1 to #; Meant to be a set of useful SNR checks, not one for every order
FULLCOMP	Is this file fully compliant with the RVSTAND EPRV standard?	N/A	String	Yes or No	UNKNOWN	True
TELFLAG	Issues with observatory or telescope?	N/A	String	Pass or Fail or Warn	PASS	False	Default to Pass. If Fail or Warn then more detail should be provided via the bitfields
INSTFLAG	Issues with instrument?	N/A	String	Pass or Fail or Warn	PASS	False	Default to Pass. If Fail or Warn then more detail should be provided via the bitfieldsx
DRPFLAG	Issues with pipeline?	N/A	String	Pass or Fail or Warn	PASS	False	Default to Pass. If Fail or Warn then more detail should be provided via the bitfields
ADDFLAG	Additional team defined flag	N/A	String	Pass or Fail or Warn		False	Note what this corresponds to in documentation
OBSFLAG	Observer pass/fail for exposure	N/A	String	Pass or Fail		False
SUMMFLAG	Summary roll up of other flag keywords	N/A	String	Pass or Fail	UNKNOWN	True
DQLVL0	Quality check bitfield of N characters	N/A	UInt	0	UNDEFINED	True	see e.g. https://neid.ipac.caltech.edu/docs/NEID-DRP/bitfields.html
DQLVL1	Quality check bitfield of N characters	N/A	UInt	0	UNDEFINED	True	see e.g. https://neid.ipac.caltech.edu/docs/NEID-DRP/bitfields.html
DQLVL2	Quality check bitfield of N characters	N/A	UInt	0	UNDEFINED	True	Standardize first few bits then leave remaining for instrument specific checks