LsstTS8Translator

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

Bases: lsst.obs.lsst.translators.lsst.LsstBaseTranslator

Metadata translator for LSST Test Stand 8 data.

Attributes Summary

DETECTOR_MAX	Maximum number of detectors to use when calculating the detector_exposure_id.
cameraPolicyFile
default_resource_package
default_resource_root
default_search_path
detectorMapping
detectorSerials
name	Name of this translation class
supported_instrument
translators

Methods Summary

are_keys_ok(keywords)	Are the supplied keys all present and defined?
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_info_from_serial(…)	Helper method to return the detector information from the serial.
compute_detector_num_from_name(…)	Helper method to return the detector number from the name.
compute_exposure_id(dateobs[, seqnum, …])	Helper method to calculate the TS8 exposure_id.
defined_in_this_class(name)	Report if the specified class attribute is defined specifically in this class.
detector_mapping()	Returns the mapping of full name to detector ID and serial.
detector_serials()	Obtain the mapping of detector serial to detector group, name, and number.
determine_translator(header[, filename])	Determine a translation class by examining the header
fix_header(header)	Apply global fixes to a supplied header.
is_key_ok(keyword)	Return True if the value associated with the named keyword is present in this header and defined.
is_keyword_defined(header, keyword)	Return True if the value associated with the named keyword is present in the supplied header and defined.
is_on_sky()	Determine if this is an on-sky observation.
max_detector_exposure_id()	The maximum detector exposure ID expected to be generated by this instrument.
max_exposure_id()	The maximum exposure ID expected from this instrument.
quantity_from_card(keywords, unit[, …])	Calculate a Astropy Quantity from a header card and a unit.
resource_root()	Package resource to use to locate correction resources within an installed package.
search_paths()	Search paths to use for LSST data when looking for header correction files.
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()	Returns the name of the raft.
to_detector_name()
to_detector_num()
to_detector_serial()	Returns the serial number of the detector.
to_detector_unique_name()	Return a unique name for the detector.
to_exposure_group()	Calculate the exposure group string.
to_exposure_id()	Generate a unique exposure ID number
to_exposure_time()	Duration of the exposure with shutter open (seconds).
to_instrument()	The instrument used to observe the exposure.
to_location()	Location of the observatory.
to_object()	Object of interest or field name.
to_observation_id()
to_observation_reason()
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_MAX = 250

Maximum number of detectors to use when calculating the detector_exposure_id.

cameraPolicyFile = 'policy/ts8.yaml'

default_resource_package = 'astro_metadata_translator'

default_resource_root = None

default_search_path = None

detectorMapping = None

detectorSerials = None

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'>, 'LSST-ImSim': <class 'lsst.obs.lsst.translators.imsim.LsstImSimTranslator'>, 'LSST-PhoSim': <class 'lsst.obs.lsst.translators.phosim.LsstPhoSimTranslator'>, 'LSST-TS3': <class 'lsst.obs.lsst.translators.ts3.LsstTS3Translator'>, 'LSST-TS8': <class 'lsst.obs.lsst.translators.ts8.LsstTS8Translator'>, 'LSST-UCDCam': <class 'lsst.obs.lsst.translators.lsst_ucdcam.LsstUCDCamTranslator'>, 'LSSTCam': <class 'lsst.obs.lsst.translators.lsstCam.LsstCamTranslator'>, 'LSSTComCam': <class 'lsst.obs.lsst.translators.comCam.LsstComCamTranslator'>, 'LSST_LATISS': <class 'lsst.obs.lsst.translators.latiss.LatissTranslator'>, 'MegaPrime': <class 'astro_metadata_translator.translators.megaprime.MegaPrimeTranslator'>, 'SDSS': <class 'astro_metadata_translator.translators.sdss.SdssTranslator'>, 'SuprimeCam': <class 'astro_metadata_translator.translators.suprimecam.SuprimeCamTranslator'>}

Methods Documentation

are_keys_ok(keywords)

Are the supplied keys all present and defined?

Parameters:

keywords : iterable of str

Keywords to test.

Returns:

all_ok : bool

True if all supplied keys are present and defined.

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-“.

Older data has no TSTAND header so we must use a combination of headers.

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.

classmethod 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_info_from_serial(detector_serial)

Helper method to return the detector information from the serial.

Parameters:

detector_serial : str

Detector serial ID.

Returns:

info : tuple of (str, str, int)

Detector group, name, and number.

classmethod compute_detector_num_from_name(detector_group, detector_name)

Helper method to return the detector number from the name.

Parameters:

detector_group : str

Name of the detector grouping. This is generally the raft name.

detector_name : str

Detector name.

Returns:

num : int

Detector number.

static compute_exposure_id(dateobs, seqnum=0, controller=None)

Helper method to calculate the TS8 exposure_id.

Parameters:

dateobs : str

Date of observation in FITS ISO format.

seqnum : int, unused

Sequence number. Ignored.

controller : str, unused

Controller type. Ignored.

Returns:

exposure_id : int

Exposure ID.

classmethod defined_in_this_class(name)

Report if the specified class attribute is defined specifically in this class.

Parameters:

name : str

Name of the attribute to test.

Returns:

in_class : bool

True if there is a attribute of that name defined in this specific subclass. False if the method is not defined in this specific subclass but is defined in a parent class. Returns None if the attribute is not defined anywhere in the class hierarchy (which can happen if translators have typos in their mapping tables).

Notes

Retrieves the attribute associated with the given name. Then looks in all the parent classes to determine whether that attribute comes from a parent class or from the current class. Attributes are compared using id().

classmethod detector_mapping()

Returns the mapping of full name to detector ID and serial.

Returns:

mapping : dict of str:tuple

Returns the mapping of full detector name (group+detector) to detector number and serial.

Raises:

ValueError

Raised if no camera policy file has been registered with this translation class.

Notes

Will construct the mapping if none has previously been constructed.

classmethod detector_serials()

Obtain the mapping of detector serial to detector group, name, and number.

Returns:

info : dict of tuple of (str, str, int)

A dict with the serial numbers as keys and values of detector group, name, and number.

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.

classmethod fix_header(header)

Apply global fixes to a supplied header.

Parameters:

header : dict

The header to correct. Correction is in place.

Returns:

modified : bool

True if a correction was applied.

Notes

This method is intended to support major discrepancies in headers such as:

• Periods of time where headers are known to be incorrect in some way that can be fixed either by deriving the correct value from the existing value or understanding the that correction is static for the given time. This requires that the date header is known.
• The presence of a certain value is always wrong and should be corrected with a new static value regardless of date.

It is assumed that one off problems with headers have been applied before this method is called using the per-obsid correction system.

Usually called from astro_metadata_translator.fix_header.

is_key_ok(keyword)

Return True if the value associated with the named keyword is present in this header and defined.

Parameters:

keyword : str

Keyword to check against header.

Returns:

is_ok : bool

True if the header is present and not-None. False otherwise.

static is_keyword_defined(header, keyword)

Return True if the value associated with the named keyword is present in the supplied header and defined.

Parameters:

header : dict-lik

Header to use as reference.

keyword : str

Keyword to check against header.

Returns:

is_defined : bool

True if the header is present and not-None. False otherwise.

is_on_sky()

Determine if this is an on-sky observation.

Returns:

is_on_sky : bool

Returns True if this is a observation on sky on the summit.

classmethod max_detector_exposure_id()

The maximum detector exposure ID expected to be generated by this instrument.

Returns:

max_id : int

The maximum value.

classmethod max_exposure_id()

The maximum exposure ID expected from this instrument.

Returns:

max_exposure_id : int

The maximum value.

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.

resource_root()

Package resource to use to locate correction resources within an installed package.

Returns:

resource_package : str

Package resource name. None if no package resource are to be used.

resource_root : str

The name of the resource root. None if no package resources are to be used.

search_paths()

Search paths to use for LSST data when looking for header correction files.

Returns:

path : list

List with a single element containing the full path to the corrections directory within the obs_lsst package.

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()

Returns the name of the raft.

Extracted from RAFTNAME header.

Raftname should be of the form: ‘LCA-11021_RTM-011-Dev’ and the resulting name will have the form “RTM-NNN”.

Returns:

name : str

Name of raft.

to_detector_name()

to_detector_num()

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_detector_unique_name()

Return a unique name for the detector.

Base class implementation attempts to combine detector_name with detector_group. Group is only used if not None.

Can be over-ridden by specialist translator class.

Returns:

name : str

detector_group``_``detector_name if detector_group is defined, else the detector_name is assumed to be unique. If neither return a valid value an exception is raised.

Raises:

NotImplementedError

Raised if neither detector_name nor detector_group is defined.

to_exposure_group()

Calculate the exposure group string.

For LSSTCam and LATISS this is read from the GROUPID header. If that header is missing the exposure_id is returned instead as a string.

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()

The instrument used to observe the exposure.

Returns:

translation : str

Translated property.

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_reason()

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.