ImsimTranslator¶

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

Bases: lsst.obs.lsst.translators.lsstsim.LsstSimTranslator

Metadata translation class for ImSim headers

Attributes Summary

`DETECTOR_MAX`
`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`(dayobs, seqnum[, controller])	Helper method to calculate the 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.
`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`()
`to_boresight_airmass`()
`to_boresight_rotation_angle`()
`to_boresight_rotation_coord`()	Coordinate frame of the instrument rotation angle (options: sky, unknown).
`to_dark_time`()	Duration of the exposure with shutter closed (seconds).
`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`()	Name of the detector within the instrument (might not be unique if there are detector groups).
`to_detector_num`()
`to_detector_serial`()	Serial number/string associated with this detector.
`to_detector_unique_name`()	Return a unique name for the detector.
`to_exposure_id`()	Unique (with instrument) integer identifier for this observation.
`to_exposure_time`()	Duration of the exposure with shutter open (seconds).
`to_instrument`()	The instrument used to observe the exposure.
`to_location`()
`to_object`()	Object of interest or field name.
`to_observation_id`()	Label uniquely identifying this observation (can be related to ‘exposure_id’).
`to_observation_type`()
`to_physical_filter`()	The bandpass filter used for this observation.
`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`()
`to_temperature`()	Temperature outside the dome.
`to_tracking_radec`()
`to_visit_id`()	ID of the Visit this Exposure is associated with.
`validate_value`(value, default[, minimum, …])	Validate the supplied value, returning a new value if out of range

Attributes Documentation

DETECTOR_MAX = 999¶

cameraPolicyFile = 'policy/imsim.yaml'¶

default_resource_package = 'astro_metadata_translator'¶

default_resource_root = None¶

default_search_path = None¶

detectorMapping = None¶

detectorSerials = None¶

name = 'ImSim'¶: 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-ComCam': <class 'lsst.obs.lsst.translators.comCam.LsstComCamTranslator'>, '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'>, 'LSST_LATISS': <class 'lsst.obs.lsst.translators.latiss.LsstLatissTranslator'>, 'MegaPrime': <class 'astro_metadata_translator.translators.megaprime.MegaPrimeTranslator'>, 'PhoSim': <class 'lsst.obs.lsst.translators.phosim.PhosimTranslator'>, '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 ImSim data. Instead we use the TESTTYPE header.

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(dayobs, seqnum, controller=None)¶

Helper method to calculate the exposure_id.

Parameters:

dayobs : str: Day of observation in either YYYYMMDD or YYYY-MM-DD format. If the string looks like ISO format it will be truncated before the T before being handled.
seqnum : int or str: Sequence number.
controller : str, optional: Controller to use. If this is “O”, no change is made to the exposure ID. If it is “C” a 1000 is added to the year component of the exposure ID. None indicates that the controller is not relevant to the exposure ID calculation (generally this is the case for test stand data).

Returns:

exposure_id : int: Exposure ID in form YYYYMMDDnnnnn form.

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.

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()¶

to_boresight_airmass()¶

to_boresight_rotation_angle()¶

to_boresight_rotation_coord()¶

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

Returns:	translation : `str` Translated property.

to_dark_time()¶

Duration of the exposure with shutter closed (seconds).

Returns:	translation : `astropy.units.Quantity` Translated value derived from the header.

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 value derived from the header.

to_detector_name()¶

Name of the detector within the instrument (might not be unique if there are detector groups).

Returns:	translation : `str` Translated value derived from the header.

to_detector_num()¶

to_detector_serial()¶

Serial number/string associated with this detector.

Returns:	translation : `str` Translated value derived from the header.

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_id()¶

Unique (with instrument) integer identifier for this observation.

Returns:	translation : `int` Translated value derived from the header.

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()¶

to_object()¶

Object of interest or field name.

Returns:	translation : `str` Translated property.

to_observation_id()¶

Label uniquely identifying this observation (can be related to ‘exposure_id’).

Returns:	translation : `str` Translated value derived from the header.

to_observation_type()¶

to_physical_filter()¶

The bandpass filter used for this observation.

Returns:	translation : `str` Translated value derived from the header.

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()¶

to_temperature()¶

Temperature outside the dome.

Returns:	translation : `astropy.units.Quantity` Translated property.

to_tracking_radec()¶

to_visit_id()¶

ID of the Visit this Exposure is associated with.

Science observations should essentially always be associated with a visit, but calibration observations may not be.

Returns:	translation : `int` Translated value derived from the header.

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.

Navigation

ImsimTranslator¶