Coverage for python/lsst/obs/base/makeRawVisitInfoViaObsInfo.py: 17%
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1# This file is part of obs_base.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (https://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
22__all__ = ["MakeRawVisitInfoViaObsInfo"]
24import logging
25import warnings
27import astropy.units
28import astropy.utils.exceptions
29from astropy.utils import iers
31# Prefer the standard pyerfa over the Astropy version
32try:
33 import erfa
35 ErfaWarning = erfa.ErfaWarning
36except ImportError:
37 import astropy._erfa as erfa
39 ErfaWarning = None
41from astro_metadata_translator import ObservationInfo
42from lsst.afw.coord import Observatory, Weather
43from lsst.afw.image import RotType, VisitInfo
44from lsst.daf.base import DateTime
45from lsst.geom import SpherePoint, degrees, radians
48class MakeRawVisitInfoViaObsInfo:
49 """Base class functor to make a VisitInfo from the FITS header of a
50 raw image using `~astro_metadata_translator.ObservationInfo` translators.
52 Subclasses can be used if a specific
53 `~astro_metadata_translator.MetadataTranslator` translator should be used.
55 The design philosophy is to make a best effort and log warnings of
56 problems, rather than raising exceptions, in order to extract as much
57 VisitInfo information as possible from a messy FITS header without the
58 user needing to add a lot of error handling.
60 Parameters
61 ----------
62 log : `logging.Logger` or None
63 Logger to use for messages.
64 (None to use
65 ``Log.getLogger("lsst.obs.base.makeRawVisitInfoViaObsInfo")``).
66 doStripHeader : `bool`, optional
67 Strip header keywords from the metadata as they are used?
68 """
70 metadataTranslator = None
71 """Header translator to use to construct VisitInfo, defaulting to
72 automatic determination."""
74 def __init__(self, log=None, doStripHeader=False):
75 if log is None:
76 log = logging.getLogger(__name__)
77 self.log = log
78 self.doStripHeader = doStripHeader
80 def __call__(self, md, exposureId=None):
81 """Construct a VisitInfo and strip associated data from the metadata.
83 Parameters
84 ----------
85 md : `lsst.daf.base.PropertyList` or `lsst.daf.base.PropertySet`
86 Metadata to pull from.
87 May be modified if ``stripHeader`` is ``True``.
88 exposureId : `int`, optional
89 Ignored. Here for compatibility with `MakeRawVisitInfo`.
91 Returns
92 -------
93 visitInfo : `lsst.afw.image.VisitInfo`
94 `~lsst.afw.image.VisitInfo` derived from the header using
95 a `~astro_metadata_translator.MetadataTranslator`.
96 """
98 obsInfo = ObservationInfo(md, translator_class=self.metadataTranslator)
100 if self.doStripHeader:
101 # Strip all the cards out that were used
102 for c in obsInfo.cards_used:
103 del md[c]
105 return self.observationInfo2visitInfo(obsInfo, log=self.log)
107 @staticmethod
108 def observationInfo2visitInfo(obsInfo, log=None):
109 """Construct a `~lsst.afw.image.VisitInfo` from an
110 `~astro_metadata_translator.ObservationInfo`
112 Parameters
113 ----------
114 obsInfo : `astro_metadata_translator.ObservationInfo`
115 Information gathered from the observation metadata.
116 log : `logging.Logger` or `lsst.log.Log`, optional
117 Logger to use for logging informational messages.
118 If `None` logging will be disabled.
120 Returns
121 -------
122 visitInfo : `lsst.afw.image.VisitInfo`
123 `~lsst.afw.image.VisitInfo` derived from the supplied
124 `~astro_metadata_translator.ObservationInfo`.
125 """
126 argDict = dict()
128 # Map the translated information into a form suitable for VisitInfo
129 if obsInfo.exposure_time is not None:
130 argDict["exposureTime"] = obsInfo.exposure_time.to_value("s")
131 if obsInfo.dark_time is not None:
132 argDict["darkTime"] = obsInfo.dark_time.to_value("s")
133 argDict["exposureId"] = obsInfo.detector_exposure_id
134 argDict["id"] = obsInfo.exposure_id
135 argDict["instrumentLabel"] = obsInfo.instrument
137 # VisitInfo uses the middle of the observation for the date
138 if obsInfo.datetime_begin is not None and obsInfo.datetime_end is not None:
139 tdelta = obsInfo.datetime_end - obsInfo.datetime_begin
140 middle = obsInfo.datetime_begin + 0.5 * tdelta
142 # DateTime uses nanosecond resolution, regardless of the resolution
143 # of the original date
144 middle.precision = 9
145 # isot is ISO8601 format with "T" separating date and time and no
146 # time zone
147 argDict["date"] = DateTime(middle.tai.isot, DateTime.TAI)
149 # Derive earth rotation angle from UT1 (being out by a second is
150 # not a big deal given the uncertainty over exactly what part of
151 # the observation we are needing it for).
152 # ERFA needs a UT1 time split into two floats
153 # We ignore any problems with DUT1 not being defined for now.
154 try:
155 # Catch any warnings about the time being in the future
156 # since there is nothing we can do about that for simulated
157 # data and it tells us nothing for data from the past.
158 with warnings.catch_warnings():
159 # If we are using the real erfa it is not an AstropyWarning
160 # During transition period filter both
161 warnings.simplefilter("ignore", category=astropy.utils.exceptions.AstropyWarning)
162 if ErfaWarning is not None:
163 warnings.simplefilter("ignore", category=ErfaWarning)
164 ut1time = middle.ut1
165 except iers.IERSRangeError:
166 ut1time = middle
168 era = erfa.era00(ut1time.jd1, ut1time.jd2)
169 argDict["era"] = era * radians
170 else:
171 argDict["date"] = DateTime()
173 # Coordinates
174 if obsInfo.tracking_radec is not None:
175 icrs = obsInfo.tracking_radec.transform_to("icrs")
176 argDict["boresightRaDec"] = SpherePoint(icrs.ra.degree, icrs.dec.degree, units=degrees)
178 altaz = obsInfo.altaz_begin
179 if altaz is not None:
180 argDict["boresightAzAlt"] = SpherePoint(altaz.az.degree, altaz.alt.degree, units=degrees)
182 argDict["boresightAirmass"] = obsInfo.boresight_airmass
184 if obsInfo.boresight_rotation_angle is not None:
185 argDict["boresightRotAngle"] = obsInfo.boresight_rotation_angle.degree * degrees
187 if obsInfo.boresight_rotation_coord is not None:
188 rotType = RotType.UNKNOWN
189 if obsInfo.boresight_rotation_coord == "sky":
190 rotType = RotType.SKY
191 argDict["rotType"] = rotType
193 # Weather and Observatory Location
194 temperature = float("nan")
195 if obsInfo.temperature is not None:
196 temperature = obsInfo.temperature.to_value("deg_C", astropy.units.temperature())
197 pressure = float("nan")
198 if obsInfo.pressure is not None:
199 pressure = obsInfo.pressure.to_value("Pa")
200 relative_humidity = float("nan")
201 if obsInfo.relative_humidity is not None:
202 relative_humidity = obsInfo.relative_humidity
203 argDict["weather"] = Weather(temperature, pressure, relative_humidity)
205 if obsInfo.location is not None:
206 geolocation = obsInfo.location.to_geodetic()
207 argDict["observatory"] = Observatory(
208 geolocation.lon.degree * degrees,
209 geolocation.lat.degree * degrees,
210 geolocation.height.to_value("m"),
211 )
213 for key in list(argDict.keys()): # use a copy because we may delete items
214 if argDict[key] is None:
215 if log is not None:
216 log.warning("argDict[%s] is None; stripping", key)
217 del argDict[key]
219 return VisitInfo(**argDict)