LsstTS8Translator

class lsst.obs.lsst.LsstTS8Translator(header, filename=None)

Bases: astro_metadata_translator.translator.StubTranslator

Metadata translator for LSST Test Stand 8 data.

Attributes Summary

DETECTOR_GROUP_NAME	Fixed name of detector group.
name	Name of this translation class
supported_instrument
translators

Methods Summary

can_translate(header[, filename])	Indicate whether this translation class can translate the supplied header.
can_translate_with_options(header, options)	Helper method for can_translate allowing options.
cards_used()	Cards used during metadata extraction.
compute_detector_exposure_id(exposure_id, …)	Compute the detector exposure ID from detector number and exposure ID.
compute_detector_name_from_num(detector_num)	Helper method to return the detector name from the number.
compute_detector_num_from_name(detector_name)	Helper method to return the detector number from the name.
compute_exposure_id(dateobs[, seqnum])	Helper method to calculate the TS8 exposure_id.
determine_translator(header[, filename])	Determine a translation class by examining the header
quantity_from_card(keywords, unit[, …])	Calculate a Astropy Quantity from a header card and a unit.
to_altaz_begin()	Telescope boresight azimuth and elevation at start of observation.
to_boresight_airmass()	Airmass of the boresight of the telescope.
to_boresight_rotation_angle()	Angle of the instrument in boresight_rotation_coord frame.
to_boresight_rotation_coord()	Coordinate frame of the instrument rotation angle (options: sky, unknown).
to_dark_time()	Calculate the dark time.
to_datetime_begin()
to_datetime_end()
to_detector_exposure_id()
to_detector_group()	Collection name of which this detector is a part.
to_detector_name()
to_detector_num()	Return value of detector_num from headers.
to_detector_serial()	Returns the serial number of the detector.
to_exposure_id()	Generate a unique exposure ID number
to_exposure_time()	Duration of the exposure with shutter open (seconds).
to_instrument()	Calculate the instrument name.
to_location()	Location of the observatory.
to_object()	Object of interest or field name.
to_observation_id()
to_observation_type()
to_physical_filter()	Return the filter name.
to_pressure()	Atmospheric pressure outside the dome.
to_relative_humidity()	Relative humidity outside the dome.
to_science_program()	Observing program (survey or proposal) identifier.
to_telescope()	Full name of the telescope.
to_temperature()	Temperature outside the dome.
to_tracking_radec()	Requested RA/Dec to track.
to_visit_id()	Generate a unique exposure ID number
validate_value(value, default[, minimum, …])	Validate the supplied value, returning a new value if out of range

Attributes Documentation

DETECTOR_GROUP_NAME = 'R00'

Fixed name of detector group.

name = 'LSST-TS8'

Name of this translation class

supported_instrument = None

translators = {'DECam': <class 'astro_metadata_translator.translators.decam.DecamTranslator'>, 'HSC': <class 'astro_metadata_translator.translators.hsc.HscTranslator'>, 'ImSim': <class 'lsst.obs.lsst.translators.imsim.ImsimTranslator'>, 'LSST-TS8': <class 'lsst.obs.lsst.translators.ts8.LsstTS8Translator'>, 'LSST-UCDCam': <class 'lsst.obs.lsst.translators.lsst_ucdcam.LsstUCDCamTranslator'>, 'LSSTAuxTel': <class 'lsst.obs.lsst.translators.auxTel.LsstAuxTelTranslator'>, 'MegaPrime': <class 'astro_metadata_translator.translators.megaprime.MegaPrimeTranslator'>, 'PhoSim': <class 'lsst.obs.lsst.translators.phosim.PhosimTranslator'>, 'SuprimeCam': <class 'astro_metadata_translator.translators.suprimecam.SuprimeCamTranslator'>}

Methods Documentation

classmethod can_translate(header, filename=None)

Indicate whether this translation class can translate the supplied header.

There is no INSTRUME header in TS8 data. Instead we use the TSTAND header. We also look at the file name to see if it starts with “ts8-“.

Parameters:

header : dict-like

Header to convert to standardized form.

filename : str, optional

Name of file being translated.

Returns:

can : bool

True if the header is recognized by this class. False otherwise.

classmethod can_translate_with_options(header, options, filename=None)

Helper method for can_translate allowing options.

Parameters:

header : dict-like

Header to convert to standardized form.

options : dict

Headers to try to determine whether this header can be translated by this class. If a card is found it will be compared with the expected value and will return that comparison. Each card will be tried in turn until one is found.

filename : str, optional

Name of file being translated.

Returns:

can : bool

True if the header is recognized by this class. False otherwise.

Notes

Intended to be used from within can_translate implementations for specific translators. Is not intended to be called directly from determine_translator.

cards_used()

Cards used during metadata extraction.

Returns:

used : frozenset of str

Cards used when extracting metadata.

static compute_detector_exposure_id(exposure_id, detector_num)

Compute the detector exposure ID from detector number and exposure ID.

This is a helper method to allow code working outside the translator infrastructure to use the same algorithm.

Parameters:

exposure_id : int

Unique exposure ID.

detector_num : int

Detector number.

Returns:

detector_exposure_id : int

The calculated ID.

classmethod compute_detector_name_from_num(detector_num)

Helper method to return the detector name from the number.

Parameters:

detector_num : int

Detector number.

Returns:

name : str

Detector name.

Raises:

IndexError

The supplied index is out of range.

TypeError

The supplied index is not an int.

classmethod compute_detector_num_from_name(detector_name)

Helper method to return the detector number from the name.

Parameters:

detector_name : str

Detector name.

Returns:

num : int

Detector number.

Raises:

ValueError

The supplied name is not known.

static compute_exposure_id(dateobs, seqnum=0)

Helper method to calculate the TS8 exposure_id.

Parameters:

dateobs : str

Date of observation in FITS ISO format.

seqnum : int, unused

Sequence number. Ignored.

Returns:

exposure_id : int

Exposure ID.

classmethod determine_translator(header, filename=None)

Determine a translation class by examining the header

Parameters:

header : dict-like

Representation of a header.

filename : str, optional

Name of file being translated.

Returns:

translator : MetadataTranslator

Translation class that knows how to extract metadata from the supplied header.

Raises:

ValueError

None of the registered translation classes understood the supplied header.

quantity_from_card(keywords, unit, default=None, minimum=None, maximum=None, checker=None)

Calculate a Astropy Quantity from a header card and a unit.

Parameters:

keywords : str or list of str

Keyword to use from header. If a list each keyword will be tried in turn until one matches.

unit : astropy.units.UnitBase

Unit of the item in the header.

default : float, optional

Default value to use if the header value is invalid. Assumed to be in the same units as the value expected in the header. If None, no default value is used.

minimum : float, optional

Minimum possible valid value, optional. If the calculated value is below this value, the default value will be used.

maximum : float, optional

Maximum possible valid value, optional. If the calculated value is above this value, the default value will be used.

checker : function, optional

Callback function to be used by the translator method in case the keyword is not present. Function will be executed as if it is a method of the translator class. Running without raising an exception will allow the default to be used. Should usually raise KeyError.

Returns:

q : astropy.units.Quantity

Quantity representing the header value.

Raises:

KeyError

The supplied header key is not present.

to_altaz_begin()

Telescope boresight azimuth and elevation at start of observation.

Returns:

translation : astropy.coordinates.AltAz

Translated property.

to_boresight_airmass()

Airmass of the boresight of the telescope.

Returns:

translation : float

Translated property.

to_boresight_rotation_angle()

Angle of the instrument in boresight_rotation_coord frame.

Returns:

translation : astropy.coordinates.Angle

Translated property.

to_boresight_rotation_coord()

Coordinate frame of the instrument rotation angle (options: sky, unknown).

Returns:

translation : str

Translated property.

to_dark_time()

Calculate the dark time.

If a DARKTIME header is not found, the value is assumed to be identical to the exposure time.

Returns:

dark : astropy.units.Quantity

The dark time in seconds.

to_datetime_begin()

to_datetime_end()

to_detector_exposure_id()

to_detector_group()

Collection name of which this detector is a part. Can be None if there are no detector groupings.

Returns:

translation : str

Translated property.

to_detector_name()

to_detector_num()

Return value of detector_num from headers.

Unique (for instrument) integer identifier for the sensor. Calculated from the raftname.

Returns:

detector_num : int

The translated property.

to_detector_serial()

Returns the serial number of the detector.

Returns:

serial : str

LSST assigned serial number.

Notes

This is the LSST assigned serial number (LSST_NUM), and not the manufacturer’s serial number (CCD_SERN).

to_exposure_id()

Generate a unique exposure ID number

Note that SEQNUM is not unique for a given day in TS8 data so instead we convert the ISO date of observation directly to an integer.

Returns:

exposure_id : int

Unique exposure number.

to_exposure_time()

Duration of the exposure with shutter open (seconds).

Returns:

translation : astropy.units.Quantity

Translated value derived from the header.

to_instrument()

Calculate the instrument name.

Returns:

instrume : str

Name of the test stand and raft combination. For example: “TS8-RTM-001”

to_location()

Location of the observatory.

Returns:

translation : astropy.coordinates.EarthLocation

Translated property.

to_object()

Object of interest or field name.

Returns:

translation : str

Translated property.

to_observation_id()

to_observation_type()

to_physical_filter()

Return the filter name.

Uses the FILTPOS header.

Returns:

filter : str

The filter name. Returns “NONE” if no filter can be determined.

Notes

The calculations here are examples rather than being accurate. They need to be fixed once the camera acquisition system does this properly.

to_pressure()

Atmospheric pressure outside the dome.

Returns:

translation : astropy.units.Quantity

Translated property.

to_relative_humidity()

Relative humidity outside the dome.

Returns:

translation : float

Translated property.

to_science_program()

Observing program (survey or proposal) identifier.

Returns:

translation : str

Translated value derived from the header.

to_telescope()

Full name of the telescope.

Returns:

translation : str

Translated property.

to_temperature()

Temperature outside the dome.

Returns:

translation : astropy.units.Quantity

Translated property.

to_tracking_radec()

Requested RA/Dec to track.

Returns:

translation : astropy.coordinates.SkyCoord

Translated property.

to_visit_id()

Generate a unique exposure ID number

Note that SEQNUM is not unique for a given day in TS8 data so instead we convert the ISO date of observation directly to an integer.

Returns:

exposure_id : int

Unique exposure number.

static validate_value(value, default, minimum=None, maximum=None)

Validate the supplied value, returning a new value if out of range

Parameters:

value : float

Value to be validated.

default : float

Default value to use if supplied value is invalid or out of range. Assumed to be in the same units as the value expected in the header.

minimum : float

Minimum possible valid value, optional. If the calculated value is below this value, the default value will be used.

maximum : float

Maximum possible valid value, optional. If the calculated value is above this value, the default value will be used.

Returns:

value : float

Either the supplied value, or a default value.