Coverage for python/lsst/obs/lsst/translators/lsst.py: 33%

394 statements  

« prev     ^ index     » next       coverage.py v7.4.1, created at 2024-02-14 10:44 +0000

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. 

10 

11"""Metadata translation support code for LSST headers""" 

12 

13__all__ = ("TZERO", "SIMONYI_LOCATION", "read_detector_ids", 

14 "compute_detector_exposure_id_generic", "LsstBaseTranslator", 

15 "SIMONYI_TELESCOPE") 

16 

17import os.path 

18import yaml 

19import logging 

20import re 

21import datetime 

22import hashlib 

23 

24import astropy.coordinates 

25import astropy.units as u 

26from astropy.time import Time, TimeDelta 

27from astropy.coordinates import EarthLocation 

28 

29from lsst.utils import getPackageDir 

30 

31from astro_metadata_translator import cache_translation, FitsTranslator 

32from astro_metadata_translator.translators.helpers import tracking_from_degree_headers, \ 

33 altaz_from_degree_headers 

34 

35 

36TZERO = Time("2015-01-01T00:00", format="isot", scale="utc") 

37TZERO_DATETIME = TZERO.to_datetime() 

38 

39# Delimiter to use for multiple filters/gratings 

40FILTER_DELIMITER = "~" 

41 

42# Regex to use for parsing a GROUPID string 

43GROUP_RE = re.compile(r"^(\d\d\d\d\-\d\d\-\d\dT\d\d:\d\d:\d\d)\.(\d\d\d)(?:[\+#](\d+))?$") 

44 

45# LSST Default location in the absence of headers 

46SIMONYI_LOCATION = EarthLocation.from_geodetic(-70.749417, -30.244639, 2663.0) 

47 

48# Name of the main survey telescope 

49SIMONYI_TELESCOPE = "Simonyi Survey Telescope" 

50 

51# Supported controller codes. 

52# The order here directly relates to the resulting exposure ID 

53# calculation. Do not reorder. Add new ones to the end. 

54# OCS, CCS, pHosim, P for simulated OCS, Q for simulated CCS, S for 

55# simulated images. 

56CONTROLLERS = "OCHPQS" 

57 

58# Number of decimal digits allocated to the sequence number in exposure_ids. 

59_SEQNUM_MAXDIGITS = 5 

60 

61# Number of decimal digits allocated to the day of observation (and controller 

62# code) in exposure_ids. 

63_DAYOBS_MAXDIGITS = 8 

64 

65# Value added to day_obs for controllers after the default. 

66_CONTROLLER_INCREMENT = 1000_00_00 

67 

68# Number of decimal digits used by exposure_ids. 

69EXPOSURE_ID_MAXDIGITS = _SEQNUM_MAXDIGITS + _DAYOBS_MAXDIGITS 

70 

71obs_lsst_packageDir = getPackageDir("obs_lsst") 

72 

73log = logging.getLogger(__name__) 

74 

75 

76def read_detector_ids(policyFile): 

77 """Read a camera policy file and retrieve the mapping from CCD name 

78 to ID. 

79 

80 Parameters 

81 ---------- 

82 policyFile : `str` 

83 Name of YAML policy file to read, relative to the obs_lsst 

84 package. 

85 

86 Returns 

87 ------- 

88 mapping : `dict` of `str` to (`int`, `str`) 

89 A `dict` with keys being the full names of the detectors, and the 

90 value is a `tuple` containing the integer detector number and the 

91 detector serial number. 

92 

93 Notes 

94 ----- 

95 Reads the camera YAML definition file directly and extracts just the 

96 IDs and serials. This routine does not use the standard 

97 `~lsst.obs.base.yamlCamera.YAMLCamera` infrastructure or 

98 `lsst.afw.cameraGeom`. This is because the translators are intended to 

99 have minimal dependencies on LSST infrastructure. 

100 """ 

101 

102 file = os.path.join(obs_lsst_packageDir, policyFile) 

103 try: 

104 with open(file) as fh: 

105 # Use the fast parser since these files are large 

106 camera = yaml.load(fh, Loader=yaml.CSafeLoader) 

107 except OSError as e: 

108 raise ValueError(f"Could not load camera policy file {file}") from e 

109 

110 mapping = {} 

111 for ccd, value in camera["CCDs"].items(): 

112 mapping[ccd] = (int(value["id"]), value["serial"]) 

113 

114 return mapping 

115 

116 

117def compute_detector_exposure_id_generic(exposure_id, detector_num, max_num): 

118 """Compute the detector_exposure_id from the exposure id and the 

119 detector number. 

120 

121 Parameters 

122 ---------- 

123 exposure_id : `int` 

124 The exposure ID. 

125 detector_num : `int` 

126 The detector number. 

127 max_num : `int` 

128 Maximum number of detectors to make space for. 

129 

130 Returns 

131 ------- 

132 detector_exposure_id : `int` 

133 Computed ID. 

134 

135 Raises 

136 ------ 

137 ValueError 

138 The detector number is out of range. 

139 """ 

140 

141 if detector_num is None: 

142 raise ValueError("Detector number must be defined.") 

143 if detector_num >= max_num or detector_num < 0: 

144 raise ValueError(f"Detector number out of range 0 <= {detector_num} < {max_num}") 

145 

146 return max_num*exposure_id + detector_num 

147 

148 

149class LsstBaseTranslator(FitsTranslator): 

150 """Translation methods useful for all LSST-style headers.""" 

151 

152 _const_map = {} 

153 _trivial_map = {} 

154 

155 # Do not specify a name for this translator 

156 cameraPolicyFile = None 

157 """Path to policy file relative to obs_lsst root.""" 

158 

159 detectorMapping = None 

160 """Mapping of detector name to detector number and serial.""" 

161 

162 detectorSerials = None 

163 """Mapping of detector serial number to raft, number, and name.""" 

164 

165 DETECTOR_MAX = 1000 

166 """Maximum number of detectors to use when calculating the 

167 detector_exposure_id. 

168 

169 Note that because this is the maximum number *of* detectors, for 

170 zero-based ``detector_num`` values this is one greater than the maximum 

171 ``detector_num``. It is also often rounded up to the nearest power of 

172 10 anyway, to allow ``detector_exposure_id`` values to be easily decoded by 

173 humans. 

174 """ 

175 

176 _DEFAULT_LOCATION = SIMONYI_LOCATION 

177 """Default telescope location in absence of relevant FITS headers.""" 

178 

179 _ROLLOVER_TIME = TimeDelta(12*60*60, scale="tai", format="sec") 

180 """Time delta for the definition of a Rubin Observatory start of day. 

181 Used when the header is missing. See LSE-400 for details.""" 

182 

183 @classmethod 

184 def __init_subclass__(cls, **kwargs): 

185 """Ensure that subclasses clear their own detector mapping entries 

186 such that subclasses of translators that use detector mappings 

187 do not pick up the incorrect values from a parent.""" 

188 

189 cls.detectorMapping = None 

190 cls.detectorSerials = None 

191 

192 super().__init_subclass__(**kwargs) 

193 

194 def search_paths(self): 

195 """Search paths to use for LSST data when looking for header correction 

196 files. 

197 

198 Returns 

199 ------- 

200 path : `list` 

201 List with a single element containing the full path to the 

202 ``corrections`` directory within the ``obs_lsst`` package. 

203 """ 

204 return [os.path.join(obs_lsst_packageDir, "corrections")] 

205 

206 @classmethod 

207 def compute_detector_exposure_id(cls, exposure_id, detector_num): 

208 """Compute the detector exposure ID from detector number and 

209 exposure ID. 

210 

211 This is a helper method to allow code working outside the translator 

212 infrastructure to use the same algorithm. 

213 

214 Parameters 

215 ---------- 

216 exposure_id : `int` 

217 Unique exposure ID. 

218 detector_num : `int` 

219 Detector number. 

220 

221 Returns 

222 ------- 

223 detector_exposure_id : `int` 

224 The calculated ID. 

225 """ 

226 from .._packer import RubinDimensionPacker 

227 

228 return RubinDimensionPacker.pack_id_pair(exposure_id, detector_num) 

229 

230 @classmethod 

231 def max_detector_exposure_id(cls): 

232 """The maximum detector exposure ID expected to be generated by 

233 this instrument. 

234 

235 Returns 

236 ------- 

237 max_id : `int` 

238 The maximum value. 

239 """ 

240 max_exposure_id = cls.max_exposure_id() 

241 # We subtract 1 from DETECTOR_MAX because LSST detector_num values are 

242 # zero-based, and detector_max is the maximum number *of* detectors, 

243 # while this returns the (inclusive) maximum ID value. 

244 return cls.compute_detector_exposure_id(max_exposure_id, cls.DETECTOR_MAX - 1) 

245 

246 @classmethod 

247 def max_exposure_id(cls): 

248 """The maximum exposure ID expected from this instrument. 

249 

250 Returns 

251 ------- 

252 max_exposure_id : `int` 

253 The maximum value. 

254 """ 

255 max_date = "2050-12-31T23:59.999" 

256 max_seqnum = 99_999 

257 # This controller triggers the largest numbers 

258 max_controller = CONTROLLERS[-1] 

259 return cls.compute_exposure_id(max_date, max_seqnum, max_controller) 

260 

261 @classmethod 

262 def detector_mapping(cls): 

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

264 

265 Returns 

266 ------- 

267 mapping : `dict` of `str`:`tuple` 

268 Returns the mapping of full detector name (group+detector) 

269 to detector number and serial. 

270 

271 Raises 

272 ------ 

273 ValueError 

274 Raised if no camera policy file has been registered with this 

275 translation class. 

276 

277 Notes 

278 ----- 

279 Will construct the mapping if none has previously been constructed. 

280 """ 

281 if cls.cameraPolicyFile is not None: 

282 if cls.detectorMapping is None: 

283 cls.detectorMapping = read_detector_ids(cls.cameraPolicyFile) 

284 else: 

285 raise ValueError(f"Translation class '{cls.__name__}' has no registered camera policy file") 

286 

287 return cls.detectorMapping 

288 

289 @classmethod 

290 def detector_serials(cls): 

291 """Obtain the mapping of detector serial to detector group, name, 

292 and number. 

293 

294 Returns 

295 ------- 

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

297 A `dict` with the serial numbers as keys and values of detector 

298 group, name, and number. 

299 """ 

300 if cls.detectorSerials is None: 

301 detector_mapping = cls.detector_mapping() 

302 

303 if detector_mapping is not None: 

304 # Form mapping to go from serial number to names/numbers 

305 serials = {} 

306 for fullname, (id, serial) in cls.detectorMapping.items(): 

307 raft, detector_name = fullname.split("_") 

308 if serial in serials: 

309 raise RuntimeError(f"Serial {serial} is defined in multiple places") 

310 serials[serial] = (raft, detector_name, id) 

311 cls.detectorSerials = serials 

312 else: 

313 raise RuntimeError("Unable to obtain detector mapping information") 

314 

315 return cls.detectorSerials 

316 

317 @classmethod 

318 def compute_detector_num_from_name(cls, detector_group, detector_name): 

319 """Helper method to return the detector number from the name. 

320 

321 Parameters 

322 ---------- 

323 detector_group : `str` 

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

325 detector_name : `str` 

326 Detector name. 

327 

328 Returns 

329 ------- 

330 num : `int` 

331 Detector number. 

332 """ 

333 fullname = f"{detector_group}_{detector_name}" 

334 

335 num = None 

336 detector_mapping = cls.detector_mapping() 

337 if detector_mapping is None: 

338 raise RuntimeError("Unable to obtain detector mapping information") 

339 

340 if fullname in detector_mapping: 

341 num = detector_mapping[fullname] 

342 else: 

343 log.warning(f"Unable to determine detector number from detector name {fullname}") 

344 return None 

345 

346 return num[0] 

347 

348 @classmethod 

349 def compute_detector_info_from_serial(cls, detector_serial): 

350 """Helper method to return the detector information from the serial. 

351 

352 Parameters 

353 ---------- 

354 detector_serial : `str` 

355 Detector serial ID. 

356 

357 Returns 

358 ------- 

359 info : `tuple` of (`str`, `str`, `int`) 

360 Detector group, name, and number. 

361 """ 

362 serial_mapping = cls.detector_serials() 

363 if serial_mapping is None: 

364 raise RuntimeError("Unable to obtain serial mapping information") 

365 

366 if detector_serial in serial_mapping: 

367 info = serial_mapping[detector_serial] 

368 else: 

369 raise RuntimeError("Unable to determine detector information from detector serial" 

370 f" {detector_serial}") 

371 

372 return info 

373 

374 @staticmethod 

375 def compute_exposure_id(dayobs, seqnum, controller=None): 

376 """Helper method to calculate the exposure_id. 

377 

378 Parameters 

379 ---------- 

380 dayobs : `str` or `int` 

381 Day of observation in either YYYYMMDD or YYYY-MM-DD format. 

382 If the string looks like ISO format it will be truncated before the 

383 ``T`` before being handled. 

384 seqnum : `int` or `str` 

385 Sequence number. 

386 controller : `str`, optional 

387 Controller to use. If this is "O", no change is made to the 

388 exposure ID. If it is "C" a 1000 is added to the year component 

389 of the exposure ID. If it is "H" a 2000 is added to the year 

390 component. This sequence continues with "P" and "Q" controllers. 

391 `None` indicates that the controller is not relevant to the 

392 exposure ID calculation (generally this is the case for test 

393 stand data). 

394 

395 Returns 

396 ------- 

397 exposure_id : `int` 

398 Exposure ID in form YYYYMMDDnnnnn form. 

399 """ 

400 # We really want an integer but the checks require a str. 

401 if isinstance(dayobs, int): 

402 dayobs = str(dayobs) 

403 

404 if "T" in dayobs: 

405 dayobs = dayobs[:dayobs.find("T")] 

406 

407 dayobs = dayobs.replace("-", "") 

408 

409 if len(dayobs) != 8: 

410 raise ValueError(f"Malformed dayobs: {dayobs}") 

411 

412 # Expect no more than 99,999 exposures in a day 

413 if seqnum >= 10**_SEQNUM_MAXDIGITS: 

414 raise ValueError(f"Sequence number ({seqnum}) exceeds limit") 

415 

416 dayobs = int(dayobs) 

417 if dayobs > 20231004 and controller == "C": 

418 # As of this date the CCS controller has a unified counter 

419 # with the OCS, so there is no need to adjust the dayobs 

420 # to make unique exposure IDs. 

421 controller = None 

422 

423 # Camera control changes the exposure ID 

424 if controller is not None: 

425 index = CONTROLLERS.find(controller) 

426 if index == -1: 

427 raise ValueError(f"Supplied controller, '{controller}' is not " 

428 f"in supported list: {CONTROLLERS}") 

429 

430 # Increment a thousand years per controller 

431 dayobs += _CONTROLLER_INCREMENT * index 

432 

433 # Form the number as a string zero padding the sequence number 

434 idstr = f"{dayobs}{seqnum:0{_SEQNUM_MAXDIGITS}d}" 

435 

436 # Exposure ID has to be an integer 

437 return int(idstr) 

438 

439 @staticmethod 

440 def unpack_exposure_id(exposure_id): 

441 """Unpack an exposure ID into dayobs, seqnum, and controller. 

442 

443 Parameters 

444 ---------- 

445 exposure_id : `int` 

446 Integer exposure ID produced by `compute_exposure_id`. 

447 

448 Returns 

449 ------- 

450 dayobs : `str` 

451 Day of observation as a YYYYMMDD string. 

452 seqnum : `int` 

453 Sequence number. 

454 controller : `str` 

455 Controller code. Will be ``O`` (but should be ignored) for IDs 

456 produced by calling `compute_exposure_id` with ``controller=None``. 

457 """ 

458 dayobs, seqnum = divmod(exposure_id, 10**_SEQNUM_MAXDIGITS) 

459 controller_index = dayobs // _CONTROLLER_INCREMENT - 2 

460 dayobs -= controller_index * _CONTROLLER_INCREMENT 

461 return (str(dayobs), seqnum, CONTROLLERS[controller_index], ) 

462 

463 def _is_on_mountain(self): 

464 """Indicate whether these data are coming from the instrument 

465 installed on the mountain. 

466 

467 Returns 

468 ------- 

469 is : `bool` 

470 `True` if instrument is on the mountain. 

471 """ 

472 if "TSTAND" in self._header: 

473 return False 

474 return True 

475 

476 def is_on_sky(self): 

477 """Determine if this is an on-sky observation. 

478 

479 Returns 

480 ------- 

481 is_on_sky : `bool` 

482 Returns True if this is a observation on sky on the 

483 summit. 

484 """ 

485 # For LSST we think on sky unless tracksys is local 

486 if self.is_key_ok("TRACKSYS"): 

487 if self._header["TRACKSYS"].lower() == "local": 

488 # not on sky 

489 return False 

490 

491 # These are obviously not on sky 

492 if self.to_observation_type() in ("bias", "dark", "flat"): 

493 return False 

494 

495 return self._is_on_mountain() 

496 

497 @cache_translation 

498 def to_location(self): 

499 # Docstring will be inherited. Property defined in properties.py 

500 if not self._is_on_mountain(): 

501 return None 

502 try: 

503 # Try standard FITS headers 

504 return super().to_location() 

505 except KeyError: 

506 return self._DEFAULT_LOCATION 

507 

508 @cache_translation 

509 def to_datetime_begin(self): 

510 # Docstring will be inherited. Property defined in properties.py 

511 self._used_these_cards("MJD-OBS") 

512 return Time(self._header["MJD-OBS"], scale="tai", format="mjd") 

513 

514 @cache_translation 

515 def to_datetime_end(self): 

516 # Docstring will be inherited. Property defined in properties.py 

517 if self.is_key_ok("DATE-END"): 

518 return super().to_datetime_end() 

519 

520 return self.to_datetime_begin() + self.to_exposure_time() 

521 

522 @cache_translation 

523 def to_detector_num(self): 

524 # Docstring will be inherited. Property defined in properties.py 

525 raft = self.to_detector_group() 

526 detector = self.to_detector_name() 

527 return self.compute_detector_num_from_name(raft, detector) 

528 

529 @cache_translation 

530 def to_detector_exposure_id(self): 

531 # Docstring will be inherited. Property defined in properties.py 

532 exposure_id = self.to_exposure_id() 

533 num = self.to_detector_num() 

534 return self.compute_detector_exposure_id(exposure_id, num) 

535 

536 @cache_translation 

537 def to_observation_type(self): 

538 # Docstring will be inherited. Property defined in properties.py 

539 obstype = self._header["IMGTYPE"] 

540 self._used_these_cards("IMGTYPE") 

541 obstype = obstype.lower() 

542 if obstype in ("skyexp", "object"): 

543 obstype = "science" 

544 return obstype 

545 

546 @cache_translation 

547 def to_observation_reason(self): 

548 # Docstring will be inherited. Property defined in properties.py 

549 for key in ("REASON", "TESTTYPE"): 

550 if self.is_key_ok(key): 

551 reason = self._header[key] 

552 self._used_these_cards(key) 

553 return reason.lower() 

554 # no specific header present so use the default translation 

555 return super().to_observation_reason() 

556 

557 @cache_translation 

558 def to_dark_time(self): 

559 """Calculate the dark time. 

560 

561 If a DARKTIME header is not found, the value is assumed to be 

562 identical to the exposure time. 

563 

564 Returns 

565 ------- 

566 dark : `astropy.units.Quantity` 

567 The dark time in seconds. 

568 """ 

569 if self.is_key_ok("DARKTIME"): 

570 darktime = self._header["DARKTIME"]*u.s 

571 self._used_these_cards("DARKTIME") 

572 else: 

573 log.warning("%s: Unable to determine dark time. Setting from exposure time.", 

574 self._log_prefix) 

575 darktime = self.to_exposure_time() 

576 return darktime 

577 

578 @cache_translation 

579 def to_exposure_id(self): 

580 """Generate a unique exposure ID number 

581 

582 This is a combination of DAYOBS and SEQNUM, and optionally 

583 CONTRLLR. 

584 

585 Returns 

586 ------- 

587 exposure_id : `int` 

588 Unique exposure number. 

589 """ 

590 if "CALIB_ID" in self._header: 

591 self._used_these_cards("CALIB_ID") 

592 return None 

593 

594 dayobs = self._header["DAYOBS"] 

595 seqnum = self._header["SEQNUM"] 

596 self._used_these_cards("DAYOBS", "SEQNUM") 

597 

598 if self.is_key_ok("CONTRLLR"): 

599 controller = self._header["CONTRLLR"] 

600 self._used_these_cards("CONTRLLR") 

601 else: 

602 controller = None 

603 

604 return self.compute_exposure_id(dayobs, seqnum, controller=controller) 

605 

606 @cache_translation 

607 def to_visit_id(self): 

608 """Calculate the visit associated with this exposure. 

609 

610 Notes 

611 ----- 

612 For LATISS and LSSTCam the default visit is derived from the 

613 exposure group. For other instruments we return the exposure_id. 

614 """ 

615 

616 exposure_group = self.to_exposure_group() 

617 # If the group is an int we return it 

618 try: 

619 visit_id = int(exposure_group) 

620 return visit_id 

621 except ValueError: 

622 pass 

623 

624 # A Group is defined as ISO date with an extension 

625 # The integer must be the same for a given group so we can never 

626 # use datetime_begin. 

627 # Nominally a GROUPID looks like "ISODATE+N" where the +N is 

628 # optional. This can be converted to seconds since epoch with 

629 # an adjustment for N. 

630 # For early data lacking that form we hash the group and return 

631 # the int. 

632 matches_date = GROUP_RE.match(exposure_group) 

633 if matches_date: 

634 iso_str = matches_date.group(1) 

635 fraction = matches_date.group(2) 

636 n = matches_date.group(3) 

637 if n is not None: 

638 n = int(n) 

639 else: 

640 n = 0 

641 iso = datetime.datetime.strptime(iso_str, "%Y-%m-%dT%H:%M:%S") 

642 

643 tdelta = iso - TZERO_DATETIME 

644 epoch = int(tdelta.total_seconds()) 

645 

646 # Form the integer from EPOCH + 3 DIGIT FRAC + 0-pad N 

647 visit_id = int(f"{epoch}{fraction}{n:04d}") 

648 else: 

649 # Non-standard string so convert to numbers 

650 # using a hash function. Use the first N hex digits 

651 group_bytes = exposure_group.encode("us-ascii") 

652 hasher = hashlib.blake2b(group_bytes) 

653 # Need to be big enough it does not possibly clash with the 

654 # date-based version above 

655 digest = hasher.hexdigest()[:14] 

656 visit_id = int(digest, base=16) 

657 

658 # To help with hash collision, append the string length 

659 visit_id = int(f"{visit_id}{len(exposure_group):02d}") 

660 

661 return visit_id 

662 

663 @cache_translation 

664 def to_physical_filter(self): 

665 """Calculate the physical filter name. 

666 

667 Returns 

668 ------- 

669 filter : `str` 

670 Name of filter. Can be a combination of FILTER, FILTER1 and FILTER2 

671 headers joined by a "~". Returns "unknown" if no filter is declared 

672 """ 

673 joined = self._join_keyword_values(["FILTER", "FILTER1", "FILTER2"], delim=FILTER_DELIMITER) 

674 if not joined: 

675 joined = "unknown" 

676 

677 # Replace instances of "NONE" with "none". 

678 joined = joined.replace("NONE", "none") 

679 

680 return joined 

681 

682 @cache_translation 

683 def to_tracking_radec(self): 

684 # RA/DEC are *derived* headers and for the case where the DATE-BEG 

685 # is 1970 they are garbage and should not be used. 

686 try: 

687 if self._header["DATE-OBS"] == self._header["DATE"]: 

688 # A fixed up date -- use AZEL as source of truth 

689 altaz = self.to_altaz_begin() 

690 radec = astropy.coordinates.SkyCoord(altaz.transform_to(astropy.coordinates.ICRS()), 

691 obstime=altaz.obstime, 

692 location=altaz.location) 

693 else: 

694 radecsys = ("RADESYS",) 

695 radecpairs = (("RASTART", "DECSTART"), ("RA", "DEC")) 

696 radec = tracking_from_degree_headers(self, radecsys, radecpairs) 

697 except Exception: 

698 # If this observation was not formally on sky then we are allowed 

699 # to return None. 

700 if self.is_on_sky(): 

701 raise 

702 radec = None 

703 

704 return radec 

705 

706 @cache_translation 

707 def to_altaz_begin(self): 

708 if not self._is_on_mountain(): 

709 return None 

710 

711 # Always attempt to find the alt/az values regardless of observation 

712 # type. 

713 return altaz_from_degree_headers(self, (("ELSTART", "AZSTART"),), 

714 self.to_datetime_begin(), is_zd=False) 

715 

716 @cache_translation 

717 def to_exposure_group(self): 

718 """Calculate the exposure group string. 

719 

720 For LSSTCam and LATISS this is read from the ``GROUPID`` header. 

721 If that header is missing the exposure_id is returned instead as 

722 a string. 

723 """ 

724 if self.is_key_ok("GROUPID"): 

725 exposure_group = self._header["GROUPID"] 

726 self._used_these_cards("GROUPID") 

727 return exposure_group 

728 return super().to_exposure_group() 

729 

730 @cache_translation 

731 def to_focus_z(self): 

732 """Return the defocal distance of the camera in units of mm. 

733 If there is no ``FOCUSZ`` value in the header it will return 

734 the default 0.0mm value. 

735 

736 Returns 

737 ------- 

738 focus_z: `astropy.units.Quantity` 

739 The defocal distance from header in mm or the 0.0mm default 

740 """ 

741 if self.is_key_ok("FOCUSZ"): 

742 focus_z = self._header["FOCUSZ"] 

743 return focus_z * u.mm 

744 return super().to_focus_z() 

745 

746 @staticmethod 

747 def _is_filter_empty(filter): 

748 """Return true if the supplied filter indicates an empty filter slot 

749 

750 Parameters 

751 ---------- 

752 filter : `str` 

753 The filter string to check. 

754 

755 Returns 

756 ------- 

757 is_empty : `bool` 

758 `True` if the filter string looks like it is referring to an 

759 empty filter slot. For example this can be if the filter is 

760 "empty" or "empty_2". 

761 """ 

762 return bool(re.match(r"empty_?\d*$", filter.lower())) 

763 

764 def _determine_primary_filter(self): 

765 """Determine the primary filter from the ``FILTER`` header. 

766 

767 Returns 

768 ------- 

769 filter : `str` 

770 The contents of the ``FILTER`` header with some appropriate 

771 defaulting. 

772 """ 

773 

774 if self.is_key_ok("FILTER"): 

775 physical_filter = self._header["FILTER"] 

776 self._used_these_cards("FILTER") 

777 

778 if self._is_filter_empty(physical_filter): 

779 physical_filter = "empty" 

780 else: 

781 # Be explicit about having no knowledge of the filter 

782 # by setting it to "unknown". It should always have a value. 

783 physical_filter = "unknown" 

784 

785 # Warn if the filter being unknown is important 

786 obstype = self.to_observation_type() 

787 if obstype not in ("bias", "dark"): 

788 log.warning("%s: Unable to determine the filter", 

789 self._log_prefix) 

790 

791 return physical_filter 

792 

793 @cache_translation 

794 def to_observing_day(self): 

795 """Return the day of observation as YYYYMMDD integer. 

796 

797 For LSSTCam and other compliant instruments this is the value 

798 of the DAYOBS header. 

799 

800 Returns 

801 ------- 

802 obs_day : `int` 

803 The day of observation. 

804 """ 

805 if self.is_key_ok("DAYOBS"): 

806 self._used_these_cards("DAYOBS") 

807 return int(self._header["DAYOBS"]) 

808 

809 # Calculate it ourselves correcting for the Rubin offset 

810 date = self.to_datetime_begin().tai 

811 date -= self._ROLLOVER_TIME 

812 return int(date.strftime("%Y%m%d")) 

813 

814 @cache_translation 

815 def to_observation_counter(self): 

816 """Return the sequence number within the observing day. 

817 

818 Returns 

819 ------- 

820 counter : `int` 

821 The sequence number for this day. 

822 """ 

823 if self.is_key_ok("SEQNUM"): 

824 # Some older LATISS data may not have the header 

825 # but this is corrected in fix_header for LATISS. 

826 self._used_these_cards("SEQNUM") 

827 return int(self._header["SEQNUM"]) 

828 

829 # This indicates a problem so we warn and return a 0 

830 log.warning("%s: Unable to determine the observation counter so returning 0", 

831 self._log_prefix) 

832 return 0 

833 

834 @cache_translation 

835 def to_boresight_rotation_coord(self): 

836 """Boresight rotation angle. 

837 

838 Only relevant for science observations. 

839 """ 

840 unknown = "unknown" 

841 if not self.is_on_sky(): 

842 return unknown 

843 

844 self._used_these_cards("ROTCOORD") 

845 coord = self._header.get("ROTCOORD", unknown) 

846 if coord is None: 

847 coord = unknown 

848 return coord 

849 

850 @cache_translation 

851 def to_boresight_airmass(self): 

852 """Calculate airmass at boresight at start of observation. 

853 

854 Notes 

855 ----- 

856 Early data are missing AMSTART header so we fall back to calculating 

857 it from ELSTART. 

858 """ 

859 if not self.is_on_sky(): 

860 return None 

861 

862 # This observation should have AMSTART 

863 amkey = "AMSTART" 

864 if self.is_key_ok(amkey): 

865 self._used_these_cards(amkey) 

866 return self._header[amkey] 

867 

868 # Instead we need to look at azel 

869 altaz = self.to_altaz_begin() 

870 if altaz is not None: 

871 return altaz.secz.to_value() 

872 

873 log.warning("%s: Unable to determine airmass of a science observation, returning 1.", 

874 self._log_prefix) 

875 return 1.0 

876 

877 @cache_translation 

878 def to_group_counter_start(self): 

879 # Effectively the start of the visit as determined by the headers. 

880 counter = self.to_observation_counter() 

881 # Older data does not have the CURINDEX header. 

882 if self.is_key_ok("CURINDEX"): 

883 # CURINDEX is 1-based. 

884 seq_start = counter - self._header["CURINDEX"] + 1 

885 self._used_these_cards("CURINDEX") 

886 return seq_start 

887 else: 

888 # If the counter is 0 we need to pick something else 

889 # that is not going to confuse the visit calculation 

890 # (since setting everything to 0 will make one big visit). 

891 return counter if counter != 0 else self.to_exposure_id() 

892 

893 @cache_translation 

894 def to_group_counter_end(self): 

895 # Effectively the end of the visit as determined by the headers. 

896 counter = self.to_observation_counter() 

897 # Older data does not have the CURINDEX or MAXINDEX headers. 

898 if self.is_key_ok("CURINDEX") and self.is_key_ok("MAXINDEX"): 

899 # CURINDEX is 1-based. CURINDEX == MAXINDEX indicates the 

900 # final exposure in the sequence. 

901 remaining = self._header["MAXINDEX"] - self._header["CURINDEX"] 

902 seq_end = counter + remaining 

903 self._used_these_cards("CURINDEX", "MAXINDEX") 

904 return seq_end 

905 else: 

906 # If the counter is 0 we need to pick something else 

907 # that is not going to confuse the visit calculation 

908 # (since setting everything to 0 will make one big visit). 

909 return counter if counter != 0 else self.to_exposure_id() 

910 

911 @cache_translation 

912 def to_has_simulated_content(self): 

913 # Check all the simulation flags. 

914 # We do not know all the simulation flags that we may have so 

915 # must check every header key. Ideally HIERARCH SIMULATE would 

916 # be a hierarchical header so _header["SIMULATE"] would return 

917 # everything. The header looks like: 

918 # 

919 # HIERARCH SIMULATE ATMCS = / ATMCS Simulation Mode 

920 # HIERARCH SIMULATE ATHEXAPOD = 0 / ATHexapod Simulation Mode 

921 # HIERARCH SIMULATE ATPNEUMATICS = / ATPneumatics Simulation Mode 

922 # HIERARCH SIMULATE ATDOME = 1 / ATDome Simulation Mode 

923 # HIERARCH SIMULATE ATSPECTROGRAPH = 0 / ATSpectrograph Simulation Mode 

924 # 

925 # So any header that includes "SIMULATE" in the key name and has a 

926 # true value implies that something in the data is simulated. 

927 for k, v in self._header.items(): 

928 if "SIMULATE" in k and v: 

929 return True 

930 

931 # If the controller is H, P, or Q then the data are simulated. 

932 ctrlr_key = "CONTRLLR" 

933 if self.is_key_ok(ctrlr_key): 

934 controller = self._header[ctrlr_key] 

935 self._used_these_cards(ctrlr_key) 

936 if controller in "HPQ": 

937 return True 

938 

939 # No simulation flags set. 

940 return False 

941 

942 @cache_translation 

943 def to_relative_humidity(self) -> float | None: 

944 key = "HUMIDITY" 

945 if self.is_key_ok(key): 

946 self._used_these_cards(key) 

947 return self._header[key] 

948 

949 return None 

950 

951 @cache_translation 

952 def to_pressure(self): 

953 key = "PRESSURE" 

954 if self.is_key_ok(key): 

955 value = self._header[key] 

956 # There has been an inconsistency in units for the pressure reading 

957 # so we need to adjust for this. 

958 if value > 10_000: 

959 unit = u.Pa 

960 else: 

961 unit = u.hPa 

962 return value * unit 

963 

964 return None 

965 

966 @cache_translation 

967 def to_temperature(self): 

968 key = "AIRTEMP" 

969 if self.is_key_ok(key): 

970 return self._header[key] * u.deg_C 

971 return None