Coverage for python/lsst/obs/lsst/translators/latiss.py: 19%
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1# This file is currently part of obs_lsst but is written to allow it
2# to be migrated to the astro_metadata_translator package at a later date.
3#
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the LICENSE file in this directory for details of code ownership.
7#
8# Use of this source code is governed by a 3-clause BSD-style
9# license that can be found in the LICENSE file.
11"""Metadata translation code for LSST LATISS headers"""
13__all__ = ("LatissTranslator", )
15import logging
16import math
18import astropy.units as u
19from astropy.time import Time
20from astropy.coordinates import EarthLocation
22from astro_metadata_translator import cache_translation
23from astro_metadata_translator.translators.helpers import is_non_science
24from .lsst import LsstBaseTranslator, FILTER_DELIMITER
25from .lsstCam import is_non_science_or_lab
27log = logging.getLogger(__name__)
30# AuxTel is not the same place as LSST
31# These coordinates read from Apple Maps
32AUXTEL_LOCATION = EarthLocation.from_geodetic(-70.747698, -30.244728, 2663.0)
34# Date instrument is taking data at telescope
35# Prior to this date many parameters are automatically nulled out
36# since the headers have not historically been reliable
37TSTART = Time("2020-01-01T00:00", format="isot", scale="utc")
39# Define the sensor and group name for AuxTel globally so that it can be used
40# in multiple places. There is no raft but for consistency with other LSST
41# cameras we define one.
42_DETECTOR_GROUP_NAME = "RXX"
43_DETECTOR_NAME = "S00"
45# Date 068 detector was put in LATISS
46DETECTOR_068_DATE = Time("2019-06-24T00:00", format="isot", scale="utc")
48# IMGTYPE header is filled in after this date
49IMGTYPE_OKAY_DATE = Time("2019-11-07T00:00", format="isot", scale="utc")
51# OBJECT IMGTYPE really means ENGTEST until this date
52OBJECT_IS_ENGTEST = Time("2020-01-27T20:00", format="isot", scale="utc")
54# RA and DEC headers are in radians until this date
55RADEC_IS_RADIANS = Time("2020-01-28T22:00", format="isot", scale="utc")
57# RASTART/DECSTART/RAEND/DECEND used wrong telescope location before this
58# 2020-02-01T00:00 we fixed the telescope location, but RASTART is still
59# in mount coordinates, so off by pointing model.
60RASTART_IS_BAD = Time("2020-05-01T00:00", format="isot", scale="utc")
62# Between RASTART_IS_BAD and this time the RASTART header uses hours
63# instead of degrees.
64RASTART_IS_HOURS = Time("2021-02-11T18:45", format="isot", scale="utc")
66# From this date RASTART is correct as-is.
67RASTART_IS_OKAY = Time("2021-02-12T00:00", format="isot", scale="utc")
69# DATE-END is not to be trusted before this date
70DATE_END_IS_BAD = Time("2020-02-01T00:00", format="isot", scale="utc")
72# The convention for the reporting of ROTPA changed by 180 here
73ROTPA_CONVENTION_180_SWITCH1 = Time("2020-11-19T00:00", format="isot", scale="utc")
74ROTPA_CONVENTION_180_SWITCH2 = Time("2021-10-29T00:00", format="isot", scale="utc")
76# TARGET is set to start with 'spec:' for dispsered images before this date
77TARGET_STARTS_SPECCOLON = Time("2022-07-10T00:00", format="isot", scale="utc")
79# Scaling factor radians to degrees. Keep it simple.
80RAD2DEG = 180.0 / math.pi
83class LatissTranslator(LsstBaseTranslator):
84 """Metadata translator for LSST LATISS data from AuxTel.
86 For lab measurements many values are masked out.
87 """
89 name = "LSST_LATISS"
90 """Name of this translation class"""
92 supported_instrument = "LATISS"
93 """Supports the LATISS instrument."""
95 _const_map = {
96 "instrument": "LATISS",
97 "telescope": "Rubin Auxiliary Telescope",
98 "detector_group": _DETECTOR_GROUP_NAME,
99 "detector_num": 0,
100 "detector_name": _DETECTOR_NAME, # Single sensor
101 }
103 _trivial_map = {
104 "observation_id": (["OBSID", "IMGNAME"], dict(default=None, checker=is_non_science)),
105 "detector_serial": ["LSST_NUM", "DETSER"],
106 "object": ("OBJECT", dict(checker=is_non_science_or_lab, default="UNKNOWN")),
107 "boresight_rotation_angle": (["ROTPA", "ROTANGLE"], dict(checker=is_non_science_or_lab,
108 default=float("nan"), unit=u.deg)),
109 "science_program": ("PROGRAM", dict(default="unknown")),
110 }
112 DETECTOR_GROUP_NAME = _DETECTOR_GROUP_NAME
113 """Fixed name of detector group."""
115 DETECTOR_NAME = _DETECTOR_NAME
116 """Fixed name of single sensor."""
118 DETECTOR_MAX = 0
119 """Maximum number of detectors to use when calculating the
120 detector_exposure_id."""
122 _DEFAULT_LOCATION = AUXTEL_LOCATION
123 """Default telescope location in absence of relevant FITS headers."""
125 @classmethod
126 def can_translate(cls, header, filename=None):
127 """Indicate whether this translation class can translate the
128 supplied header.
130 Parameters
131 ----------
132 header : `dict`-like
133 Header to convert to standardized form.
134 filename : `str`, optional
135 Name of file being translated.
137 Returns
138 -------
139 can : `bool`
140 `True` if the header is recognized by this class. `False`
141 otherwise.
142 """
143 # INSTRUME keyword might be of two types
144 if "INSTRUME" in header:
145 instrume = header["INSTRUME"]
146 for v in ("LSST_ATISS", "LATISS"):
147 if instrume == v:
148 return True
149 # Calibration files strip important headers at the moment so guess
150 if "DETNAME" in header and header["DETNAME"] == "RXX_S00":
151 return True
152 return False
154 @classmethod
155 def fix_header(cls, header, instrument, obsid, filename=None):
156 """Fix an incorrect LATISS header.
158 Parameters
159 ----------
160 header : `dict`
161 The header to update. Updates are in place.
162 instrument : `str`
163 The name of the instrument.
164 obsid : `str`
165 Unique observation identifier associated with this header.
166 Will always be provided.
167 filename : `str`, optional
168 Filename associated with this header. May not be set since headers
169 can be fixed independently of any filename being known.
171 Returns
172 -------
173 modified = `bool`
174 Returns `True` if the header was updated.
176 Notes
177 -----
178 This method does not apply per-obsid corrections. The following
179 corrections are applied:
181 * On June 24th 2019 the detector was changed from ITL-3800C-098
182 to ITL-3800C-068. The header is intended to be correct in the
183 future.
184 * In late 2019 the DATE-OBS and MJD-OBS headers were reporting
185 1970 dates. To correct, the DATE/MJD headers are copied in to
186 replace them and the -END headers are cleared.
187 * Until November 2019 the IMGTYPE was set in the GROUPID header.
188 The value is moved to IMGTYPE.
189 * SHUTTIME is always forced to be `None`.
191 Corrections are reported as debug level log messages.
193 See `~astro_metadata_translator.fix_header` for details of the general
194 process.
195 """
196 modified = False
198 # Calculate the standard label to use for log messages
199 log_label = cls._construct_log_prefix(obsid, filename)
201 if "OBSID" not in header:
202 # Very old data used IMGNAME
203 header["OBSID"] = obsid
204 modified = True
205 # We are reporting the OBSID so no need to repeat it at start
206 # of log message. Use filename if we have it.
207 log_prefix = f"{filename}: " if filename else ""
208 log.debug("%sAssigning OBSID to a value of '%s'", log_prefix, header["OBSID"])
210 if "DAYOBS" not in header:
211 # OBS-NITE could have the value for DAYOBS but it is safer
212 # for older data to set it from the OBSID. Fall back to OBS-NITE
213 # if we have no alternative
214 dayObs = None
215 try:
216 dayObs = obsid.split("_", 3)[2]
217 except (AttributeError, ValueError):
218 # did not split as expected
219 pass
220 if dayObs is None or len(dayObs) != 8:
221 if "OBS-NITE" in header:
222 dayObs = header["OBS-NITE"]
223 log.debug("%s: Setting DAYOBS to '%s' from OBS-NITE header", log_label, dayObs)
224 else:
225 log.debug("%s: Unable to determine DAYOBS from header", log_label)
226 else:
227 log.debug("%s: Setting DAYOBS to '%s' from OBSID", log_label, dayObs)
228 if dayObs:
229 header["DAYOBS"] = dayObs
230 modified = True
232 if "SEQNUM" not in header:
233 try:
234 seqnum = obsid.split("_", 3)[3]
235 except (AttributeError, ValueError):
236 # did not split as expected
237 pass
238 else:
239 header["SEQNUM"] = int(seqnum)
240 modified = True
241 log.debug("%s: Extracting SEQNUM of '%s' from OBSID", log_label, header["SEQNUM"])
243 # The DATE-OBS / MJD-OBS keys can be 1970
244 if "DATE-OBS" in header and header["DATE-OBS"].startswith("1970"):
245 # Copy the headers from the DATE and MJD since we have no other
246 # choice.
247 header["DATE-OBS"] = header["DATE"]
248 header["DATE-BEG"] = header["DATE-OBS"]
249 header["MJD-OBS"] = header["MJD"]
250 header["MJD-BEG"] = header["MJD-OBS"]
252 # And clear the DATE-END and MJD-END -- the translator will use
253 # EXPTIME instead.
254 header["DATE-END"] = None
255 header["MJD-END"] = None
257 log.debug("%s: Forcing 1970 dates to '%s'", log_label, header["DATE"])
258 modified = True
260 # Create a translator since we need the date
261 translator = cls(header)
262 date = translator.to_datetime_begin()
263 if date > DETECTOR_068_DATE:
264 header["LSST_NUM"] = "ITL-3800C-068"
265 log.debug("%s: Forcing detector serial to %s", log_label, header["LSST_NUM"])
266 modified = True
268 if date < DATE_END_IS_BAD:
269 # DATE-END may or may not be in TAI and may or may not be
270 # before DATE-BEG. Simpler to clear it
271 if header.get("DATE-END"):
272 header["DATE-END"] = None
273 header["MJD-END"] = None
275 log.debug("%s: Clearing DATE-END as being untrustworthy", log_label)
276 modified = True
278 # Up until a certain date GROUPID was the IMGTYPE
279 if date < IMGTYPE_OKAY_DATE:
280 groupId = header.get("GROUPID")
281 if groupId and not groupId.startswith("test"):
282 imgType = header.get("IMGTYPE")
283 if not imgType:
284 if "_" in groupId:
285 # Sometimes have the form dark_0001_0002
286 # in this case we pull the IMGTYPE off the front and
287 # do not clear groupId (although groupId may now
288 # repeat on different days).
289 groupId, _ = groupId.split("_", 1)
290 elif groupId.upper() != "FOCUS" and groupId.upper().startswith("FOCUS"):
291 # If it is exactly FOCUS we want groupId cleared
292 groupId = "FOCUS"
293 else:
294 header["GROUPID"] = None
295 header["IMGTYPE"] = groupId
296 log.debug("%s: Setting IMGTYPE to '%s' from GROUPID", log_label, header["IMGTYPE"])
297 modified = True
298 else:
299 # Someone could be fixing headers in old data
300 # and we do not want GROUPID == IMGTYPE
301 if imgType == groupId:
302 # Clear the group so we default to original
303 header["GROUPID"] = None
305 # We were using OBJECT for engineering observations early on
306 if date < OBJECT_IS_ENGTEST:
307 imgType = header.get("IMGTYPE")
308 if imgType == "OBJECT":
309 header["IMGTYPE"] = "ENGTEST"
310 log.debug("%s: Changing OBJECT observation type to %s",
311 log_label, header["IMGTYPE"])
312 modified = True
314 # Early on the RA/DEC headers were stored in radians
315 if date < RADEC_IS_RADIANS:
316 if header.get("RA") is not None:
317 header["RA"] *= RAD2DEG
318 log.debug("%s: Changing RA header to degrees", log_label)
319 modified = True
320 if header.get("DEC") is not None:
321 header["DEC"] *= RAD2DEG
322 log.debug("%s: Changing DEC header to degrees", log_label)
323 modified = True
325 if header.get("SHUTTIME"):
326 log.debug("%s: Forcing SHUTTIME header to be None", log_label)
327 header["SHUTTIME"] = None
328 modified = True
330 if "OBJECT" not in header:
331 # Only patch OBJECT IMGTYPE
332 if "IMGTYPE" in header and header["IMGTYPE"] == "OBJECT":
333 log.debug("%s: Forcing OBJECT header to exist", log_label)
334 header["OBJECT"] = "NOTSET"
335 modified = True
337 if date < TARGET_STARTS_SPECCOLON:
338 if (obj := header.get("OBJECT", None)) is not None:
339 header["OBJECT"] = obj.replace('spec:', '')
340 modified = True
342 if "RADESYS" in header:
343 if header["RADESYS"] == "":
344 # Default to ICRS
345 header["RADESYS"] = "ICRS"
346 log.debug("%s: Forcing blank RADESYS to '%s'", log_label, header["RADESYS"])
347 modified = True
349 if date < RASTART_IS_HOURS:
350 # Avoid two checks for case where RASTART is fine
351 if date < RASTART_IS_BAD:
352 # The wrong telescope position was used. Unsetting these will
353 # force the RA/DEC demand headers to be used instead.
354 for h in ("RASTART", "DECSTART", "RAEND", "DECEND"):
355 header[h] = None
356 log.debug("%s: Forcing derived RA/Dec headers to undefined", log_label)
357 modified = True
358 else:
359 # Correct hours to degrees
360 for h in ("RASTART", "RAEND"):
361 if header[h]:
362 header[h] *= 15.0
363 log.debug("%s: Correcting RASTART/END from hours to degrees", log_label)
364 modified = True
366 # RASTART/END headers have a TAI/UTC confusion causing an offset
367 # of 37 seconds for a period of time.
368 if RASTART_IS_BAD < date < RASTART_IS_OKAY:
369 modified = True
370 offset = (37.0 / 3600.0) * 15.0
371 for epoch in ("START", "END"):
372 h = "RA" + epoch
373 if header[h]:
374 header[h] += offset
376 if date < ROTPA_CONVENTION_180_SWITCH2 and date > ROTPA_CONVENTION_180_SWITCH1:
377 header['ROTPA'] = header['ROTPA'] - 180
378 modified = True
380 if obsgeo := header.get("OBSGEO-Z"):
381 try:
382 if obsgeo > 0.0:
383 obsgeo *= -1.0
384 header["OBSGEO-Z"] = obsgeo
385 modified = True
386 except TypeError:
387 pass
389 return modified
391 def _is_on_mountain(self):
392 date = self.to_datetime_begin()
393 if date > TSTART:
394 return True
395 return False
397 @staticmethod
398 def compute_detector_exposure_id(exposure_id, detector_num):
399 # Docstring inherited.
400 if detector_num != 0:
401 log.warning("Unexpected non-zero detector number for LATISS")
402 return LsstBaseTranslator.compute_detector_exposure_id(exposure_id, detector_num)
404 @cache_translation
405 def to_dark_time(self):
406 # Docstring will be inherited. Property defined in properties.py
408 # Always compare with exposure time
409 # We may revisit this later if there is a cutoff date where we
410 # can always trust the header.
411 exptime = self.to_exposure_time()
413 if self.is_key_ok("DARKTIME"):
414 darktime = self.quantity_from_card("DARKTIME", u.s)
415 if darktime >= exptime:
416 return darktime
417 reason = "Dark time less than exposure time."
418 else:
419 reason = "Dark time not defined."
421 log.warning("%s: %s Setting dark time to the exposure time.",
422 self._log_prefix, reason)
423 return exptime
425 @cache_translation
426 def to_exposure_time(self):
427 # Docstring will be inherited. Property defined in properties.py
428 # Some data is missing a value for EXPTIME.
429 # Have to be careful we do not have circular logic when trying to
430 # guess
431 if self.is_key_ok("EXPTIME"):
432 return self.quantity_from_card("EXPTIME", u.s)
434 # A missing or undefined EXPTIME is problematic. Set to -1
435 # to indicate that none was found.
436 log.warning("%s: Insufficient information to derive exposure time. Setting to -1.0s",
437 self._log_prefix)
438 return -1.0 * u.s
440 @cache_translation
441 def to_observation_type(self):
442 """Determine the observation type.
444 In the absence of an ``IMGTYPE`` header, assumes lab data is always a
445 dark if exposure time is non-zero, else bias.
447 Returns
448 -------
449 obstype : `str`
450 Observation type.
451 """
453 # LATISS observation type is documented to appear in OBSTYPE
454 # but for historical reasons prefers IMGTYPE.
455 # Test the keys in order until we find one that contains a
456 # defined value.
457 obstype_keys = ["OBSTYPE", "IMGTYPE"]
459 obstype = None
460 for k in obstype_keys:
461 if self.is_key_ok(k):
462 obstype = self._header[k]
463 self._used_these_cards(k)
464 obstype = obstype.lower()
465 break
467 if obstype is not None:
468 if obstype == "object" and not self._is_on_mountain():
469 # Do not map object to science in lab since most
470 # code assume science is on sky with RA/Dec.
471 obstype = "labobject"
472 elif obstype in ("skyexp", "object"):
473 obstype = "science"
475 return obstype
477 # In the absence of any observation type information, return
478 # unknown unless we think it might be a bias.
479 exptime = self.to_exposure_time()
480 if exptime == 0.0:
481 obstype = "bias"
482 else:
483 obstype = "unknown"
484 log.warning("%s: Unable to determine observation type. Guessing '%s'",
485 self._log_prefix, obstype)
486 return obstype
488 @cache_translation
489 def to_physical_filter(self):
490 """Calculate the physical filter name.
492 Returns
493 -------
494 filter : `str`
495 Name of filter. A combination of FILTER and GRATING
496 headers joined by a "~". The filter and grating are always
497 combined. The filter or grating part will be "none" if no value
498 is specified. Uses "empty" if any of the filters or gratings
499 indicate an "empty_N" name. "unknown" indicates that the filter is
500 not defined anywhere but we think it should be. "none" indicates
501 that the filter was not defined but the observation is a dark
502 or bias.
503 """
505 physical_filter = self._determine_primary_filter()
507 if self.is_key_ok("GRATING"):
508 grating = self._header["GRATING"]
509 self._used_these_cards("GRATING")
511 if not grating or grating.lower().startswith("empty"):
512 grating = "empty"
513 else:
514 # Be explicit about having no knowledge of the grating
515 grating = "unknown"
517 physical_filter = f"{physical_filter}{FILTER_DELIMITER}{grating}"
519 return physical_filter