Coverage for python/astro_metadata_translator/translators/decam.py: 34%
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« prev ^ index » next coverage.py v7.2.7, created at 2023-06-27 02:38 -0700
1# This file is part of astro_metadata_translator.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the LICENSE file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# Use of this source code is governed by a 3-clause BSD-style
10# license that can be found in the LICENSE file.
12"""Metadata translation code for DECam FITS headers"""
14from __future__ import annotations
16__all__ = ("DecamTranslator",)
18import logging
19import posixpath
20import re
21from collections.abc import Iterator, Mapping, MutableMapping
22from typing import TYPE_CHECKING, Any
24import astropy.units as u
25from astropy.coordinates import Angle, EarthLocation
26from astropy.io import fits
28from ..translator import CORRECTIONS_RESOURCE_ROOT, cache_translation
29from .fits import FitsTranslator
30from .helpers import altaz_from_degree_headers, is_non_science, tracking_from_degree_headers
32if TYPE_CHECKING: 32 ↛ 33line 32 didn't jump to line 33, because the condition on line 32 was never true
33 import astropy.coordinates
34 import astropy.time
36log = logging.getLogger(__name__)
39class DecamTranslator(FitsTranslator):
40 """Metadata translator for DECam standard headers."""
42 name = "DECam"
43 """Name of this translation class"""
45 supported_instrument = "DECam"
46 """Supports the DECam instrument."""
48 default_resource_root = posixpath.join(CORRECTIONS_RESOURCE_ROOT, "DECam")
49 """Default resource path root to use to locate header correction files."""
51 # DECam has no rotator, and the instrument angle on sky is set to +Y=East,
52 # +X=South which we define as a 90 degree rotation and an X-flip.
53 _const_map = {
54 "boresight_rotation_angle": Angle(90 * u.deg),
55 "boresight_rotation_coord": "sky",
56 }
58 _trivial_map: dict[str, str | list[str] | tuple[Any, ...]] = {
59 "exposure_time": ("EXPTIME", dict(unit=u.s)),
60 "dark_time": ("DARKTIME", dict(unit=u.s)),
61 "boresight_airmass": ("AIRMASS", dict(checker=is_non_science)),
62 "observation_id": "OBSID",
63 "object": "OBJECT",
64 "science_program": "PROPID",
65 "detector_num": "CCDNUM",
66 "detector_serial": "DETECTOR",
67 "detector_unique_name": "DETPOS",
68 "telescope": ("TELESCOP", dict(default="CTIO 4.0-m telescope")),
69 "instrument": ("INSTRUME", dict(default="DECam")),
70 # Ensure that reasonable values are always available
71 "relative_humidity": ("HUMIDITY", dict(default=40.0, minimum=0, maximum=100.0)),
72 "temperature": ("OUTTEMP", dict(unit=u.deg_C, default=10.0, minimum=-10.0, maximum=40.0)),
73 # Header says torr but seems to be mbar. Use hPa unit
74 # which is the SI equivalent of mbar.
75 "pressure": ("PRESSURE", dict(unit=u.hPa, default=771.611, minimum=700.0, maximum=850.0)),
76 }
78 # Unique detector names are currently not used but are read directly from
79 # header.
80 # The detector_group could be N or S with detector_name corresponding
81 # to the number in that group.
82 detector_names = {
83 1: "S29",
84 2: "S30",
85 3: "S31",
86 4: "S25",
87 5: "S26",
88 6: "S27",
89 7: "S28",
90 8: "S20",
91 9: "S21",
92 10: "S22",
93 11: "S23",
94 12: "S24",
95 13: "S14",
96 14: "S15",
97 15: "S16",
98 16: "S17",
99 17: "S18",
100 18: "S19",
101 19: "S8",
102 20: "S9",
103 21: "S10",
104 22: "S11",
105 23: "S12",
106 24: "S13",
107 25: "S1",
108 26: "S2",
109 27: "S3",
110 28: "S4",
111 29: "S5",
112 30: "S6",
113 31: "S7",
114 32: "N1",
115 33: "N2",
116 34: "N3",
117 35: "N4",
118 36: "N5",
119 37: "N6",
120 38: "N7",
121 39: "N8",
122 40: "N9",
123 41: "N10",
124 42: "N11",
125 43: "N12",
126 44: "N13",
127 45: "N14",
128 46: "N15",
129 47: "N16",
130 48: "N17",
131 49: "N18",
132 50: "N19",
133 51: "N20",
134 52: "N21",
135 53: "N22",
136 54: "N23",
137 55: "N24",
138 56: "N25",
139 57: "N26",
140 58: "N27",
141 59: "N28",
142 60: "N29",
143 62: "N31",
144 }
146 @classmethod
147 def can_translate(cls, header: Mapping[str, Any], filename: str | None = None) -> bool:
148 """Indicate whether this translation class can translate the
149 supplied header.
151 Checks the INSTRUME and FILTER headers.
153 Parameters
154 ----------
155 header : `dict`-like
156 Header to convert to standardized form.
157 filename : `str`, optional
158 Name of file being translated.
160 Returns
161 -------
162 can : `bool`
163 `True` if the header is recognized by this class. `False`
164 otherwise.
165 """
166 # Use INSTRUME. Because of defaulting behavior only do this
167 # if we really have an INSTRUME header
168 if "INSTRUME" in header:
169 via_instrume = super().can_translate(header, filename=filename)
170 if via_instrume:
171 return via_instrume
172 if cls.is_keyword_defined(header, "FILTER") and "DECam" in header["FILTER"]:
173 return True
174 return False
176 @cache_translation
177 def to_exposure_id(self) -> int:
178 """Calculate exposure ID.
180 Returns
181 -------
182 id : `int`
183 ID of exposure.
184 """
185 value = self._header["EXPNUM"]
186 self._used_these_cards("EXPNUM")
187 return value
189 @cache_translation
190 def to_observation_counter(self) -> int:
191 """Return the lifetime exposure number.
193 Returns
194 -------
195 sequence : `int`
196 The observation counter.
197 """
198 return self.to_exposure_id()
200 @cache_translation
201 def to_visit_id(self) -> int:
202 # Docstring will be inherited. Property defined in properties.py
203 return self.to_exposure_id()
205 @cache_translation
206 def to_datetime_end(self) -> astropy.time.Time:
207 # Docstring will be inherited. Property defined in properties.py
208 # Instcals have no DATE-END or DTUTC
209 datetime_end = self._from_fits_date("DTUTC", scale="utc")
210 if datetime_end is None:
211 datetime_end = self.to_datetime_begin() + self.to_exposure_time()
212 return datetime_end
214 def _translate_from_calib_id(self, field: str) -> str:
215 """Fetch the ID from the CALIB_ID header.
217 Calibration products made with constructCalibs have some metadata
218 saved in its FITS header CALIB_ID.
219 """
220 data = self._header["CALIB_ID"]
221 match = re.search(r".*%s=(\S+)" % field, data)
222 if not match:
223 raise RuntimeError(f"Header CALIB_ID with value '{data}' has not field '{field}'")
224 self._used_these_cards("CALIB_ID")
225 return match.groups()[0]
227 @cache_translation
228 def to_physical_filter(self) -> str | None:
229 """Calculate physical filter.
231 Return `None` if the keyword FILTER does not exist in the header,
232 which can happen for some valid Community Pipeline products.
234 Returns
235 -------
236 filter : `str`
237 The full filter name.
238 """
239 if self.is_key_ok("FILTER"):
240 value = self._header["FILTER"].strip()
241 self._used_these_cards("FILTER")
242 return value
243 elif self.is_key_ok("CALIB_ID"):
244 return self._translate_from_calib_id("filter")
245 else:
246 return None
248 @cache_translation
249 def to_location(self) -> astropy.coordinates.EarthLocation:
250 """Calculate the observatory location.
252 Returns
253 -------
254 location : `astropy.coordinates.EarthLocation`
255 An object representing the location of the telescope.
256 """
258 if self.is_key_ok("OBS-LONG"):
259 # OBS-LONG has west-positive sign so must be flipped
260 lon = self._header["OBS-LONG"] * -1.0
261 value = EarthLocation.from_geodetic(lon, self._header["OBS-LAT"], self._header["OBS-ELEV"])
262 self._used_these_cards("OBS-LONG", "OBS-LAT", "OBS-ELEV")
263 else:
264 # Look up the value since some files do not have location
265 value = EarthLocation.of_site("ctio")
267 return value
269 @cache_translation
270 def to_observation_type(self) -> str:
271 """Calculate the observation type.
273 Returns
274 -------
275 typ : `str`
276 Observation type. Normalized to standard set.
277 """
278 if not self.is_key_ok("OBSTYPE"):
279 return "none"
280 obstype = self._header["OBSTYPE"].strip().lower()
281 self._used_these_cards("OBSTYPE")
282 if obstype == "object":
283 return "science"
284 return obstype
286 @cache_translation
287 def to_tracking_radec(self) -> astropy.coordinates.SkyCoord:
288 # Docstring will be inherited. Property defined in properties.py
289 radecsys = ("RADESYS",)
290 radecpairs = (("TELRA", "TELDEC"),)
291 return tracking_from_degree_headers(self, radecsys, radecpairs, unit=(u.hourangle, u.deg))
293 @cache_translation
294 def to_altaz_begin(self) -> astropy.coordinates.AltAz:
295 # Docstring will be inherited. Property defined in properties.py
296 return altaz_from_degree_headers(self, (("ZD", "AZ"),), self.to_datetime_begin(), is_zd={"ZD"})
298 @cache_translation
299 def to_detector_exposure_id(self) -> int | None:
300 # Docstring will be inherited. Property defined in properties.py
301 exposure_id = self.to_exposure_id()
302 if exposure_id is None:
303 return None
304 return int(f"{exposure_id:07d}{self.to_detector_num():02d}")
306 @cache_translation
307 def to_detector_group(self) -> str:
308 # Docstring will be inherited. Property defined in properties.py
309 name = self.to_detector_unique_name()
310 return name[0]
312 @cache_translation
313 def to_detector_name(self) -> str:
314 # Docstring will be inherited. Property defined in properties.py
315 name = self.to_detector_unique_name()
316 return name[1:]
318 @cache_translation
319 def to_focus_z(self) -> u.Quantity:
320 # Docstring will be inherited. Property defined in properties.py
321 # ``TELFOCUS`` is a comma-separated string with six focus offsets
322 # (fx, fy, fz, tx, ty, tz) recorded in units of microns.
323 tel_focus_list = self._header["TELFOCUS"].split(",")
324 return float(tel_focus_list[2]) * u.um
326 @classmethod
327 def fix_header(
328 cls, header: MutableMapping[str, Any], instrument: str, obsid: str, filename: str | None = None
329 ) -> bool:
330 """Fix DECam headers.
332 Parameters
333 ----------
334 header : `dict`
335 The header to update. Updates are in place.
336 instrument : `str`
337 The name of the instrument.
338 obsid : `str`
339 Unique observation identifier associated with this header.
340 Will always be provided.
341 filename : `str`, optional
342 Filename associated with this header. May not be set since headers
343 can be fixed independently of any filename being known.
345 Returns
346 -------
347 modified = `bool`
348 Returns `True` if the header was updated.
350 Notes
351 -----
352 Fixes the following issues:
354 * If OBSTYPE contains "zero" or "bias",
355 update the FILTER keyword to "solid plate 0.0 0.0".
357 Corrections are reported as debug level log messages.
358 """
359 modified = False
361 # Calculate the standard label to use for log messages
362 log_label = cls._construct_log_prefix(obsid, filename)
364 obstype = header.get("OBSTYPE", "unknown")
366 if "bias" in obstype.lower() or "zero" in obstype.lower():
367 header["FILTER"] = "solid plate 0.0 0.0"
368 modified = True
369 log.debug("%s: Set FILTER to %s because OBSTYPE is %s", log_label, header["FILTER"], obstype)
371 return modified
373 @classmethod
374 def determine_translatable_headers(
375 cls, filename: str, primary: MutableMapping[str, Any] | None = None
376 ) -> Iterator[MutableMapping[str, Any]]:
377 """Given a file return all the headers usable for metadata translation.
379 DECam files are multi-extension FITS with a primary header and
380 each detector stored in a subsequent extension. DECam uses
381 ``INHERIT=T`` and each detector header will be merged with the
382 primary header.
384 Guide headers are not returned.
386 Parameters
387 ----------
388 filename : `str`
389 Path to a file in a format understood by this translator.
390 primary : `dict`-like, optional
391 The primary header obtained by the caller. This is sometimes
392 already known, for example if a system is trying to bootstrap
393 without already knowing what data is in the file. Will be
394 merged with detector headers if supplied, else will be read
395 from the file.
397 Yields
398 ------
399 headers : iterator of `dict`-like
400 Each detector header in turn. The supplied header will be merged
401 with the contents of each detector header.
403 Notes
404 -----
405 This translator class is specifically tailored to raw DECam data and
406 is not designed to work with general FITS files. The normal paradigm
407 is for the caller to have read the first header and then called
408 `determine_translator()` on the result to work out which translator
409 class to then call to obtain the real headers to be used for
410 translation.
411 """
412 # Circular dependency so must defer import.
413 from ..headers import merge_headers
415 # This is convoluted because we need to turn an Optional variable
416 # to a Dict so that mypy is happy.
417 primary_hdr = primary if primary else {}
419 # Since we want to scan many HDUs we use astropy directly to keep
420 # the file open rather than continually opening and closing it
421 # as we go to each HDU.
422 with fits.open(filename) as fits_file:
423 # Astropy does not automatically handle the INHERIT=T in
424 # DECam headers so the primary header must be merged.
425 first_pass = True
427 for hdu in fits_file:
428 if first_pass:
429 if not primary_hdr:
430 primary_hdr = hdu.header
431 first_pass = False
432 continue
434 header = hdu.header
435 if "CCDNUM" not in header: # Primary does not have CCDNUM
436 continue
437 if header["CCDNUM"] > 62: # ignore guide CCDs
438 continue
439 yield merge_headers([primary_hdr, header], mode="overwrite")