Coverage for python/lsst/obs/base/makeRawVisitInfoViaObsInfo.py : 16%

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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/>.
22import warnings
23import astropy.units
24import astropy.utils.exceptions
25from astropy.utils import iers
27# This is an unofficial ERFA interface provided by Astropy.
28# We need to use this to calculate the Earth rotation angle.
29# If Astropy change their ERFA support we will need to either bring the
30# calculation into this package or use another python ERFA binding.
31import astropy._erfa as erfa
33from astro_metadata_translator import ObservationInfo
35from lsst.log import Log
36from lsst.daf.base import DateTime
37from lsst.geom import degrees, radians
38from lsst.afw.image import VisitInfo, RotType
39from lsst.afw.coord import Observatory, Weather
40from lsst.geom import SpherePoint
42__all__ = ["MakeRawVisitInfoViaObsInfo"]
45class MakeRawVisitInfoViaObsInfo(object):
46 """Base class functor to make a VisitInfo from the FITS header of a
47 raw image using `~astro_metadata_translator.ObservationInfo` translators.
49 Subclasses can be used if a specific
50 `~astro_metadata_translator.MetadataTranslator` translator should be used.
52 The design philosophy is to make a best effort and log warnings of
53 problems, rather than raising exceptions, in order to extract as much
54 VisitInfo information as possible from a messy FITS header without the
55 user needing to add a lot of error handling.
57 Parameters
58 ----------
59 log : `lsst.log.Log` or None
60 Logger to use for messages.
61 (None to use ``Log.getLogger("MakeRawVisitInfoViaObsInfo")``).
62 doStripHeader : `bool`, optional
63 Strip header keywords from the metadata as they are used?
64 """
66 metadataTranslator = None
67 """Header translator to use to construct VisitInfo, defaulting to
68 automatic determination."""
70 def __init__(self, log=None, doStripHeader=False):
71 if log is None:
72 log = Log.getLogger("MakeRawVisitInfoViaObsInfo")
73 self.log = log
74 self.doStripHeader = doStripHeader
76 def __call__(self, md, exposureId=None):
77 """Construct a VisitInfo and strip associated data from the metadata.
79 Parameters
80 ----------
81 md : `lsst.daf.base.PropertyList` or `lsst.daf.base.PropertySet`
82 Metadata to pull from.
83 May be modified if ``stripHeader`` is ``True``.
84 exposureId : `int`, optional
85 Ignored. Here for compatibility with `MakeRawVisitInfo`.
87 Returns
88 -------
89 visitInfo : `lsst.afw.image.VisitInfo`
90 `~lsst.afw.image.VisitInfo` derived from the header using
91 a `~astro_metadata_translator.MetadataTranslator`.
92 """
94 obsInfo = ObservationInfo(md, translator_class=self.metadataTranslator)
96 if self.doStripHeader:
97 # Strip all the cards out that were used
98 for c in obsInfo.cards_used:
99 del md[c]
101 return self.observationInfo2visitInfo(obsInfo, log=self.log)
103 @staticmethod
104 def observationInfo2visitInfo(obsInfo, log=None):
105 """Construct a `~lsst.afw.image.VisitInfo` from an
106 `~astro_metadata_translator.ObservationInfo`
108 Parameters
109 ----------
110 obsInfo : `astro_metadata_translator.ObservationInfo`
111 Information gathered from the observation metadata.
112 log : `logging.Logger` or `lsst.log.Log`, optional
113 Logger to use for logging informational messages.
114 If `None` logging will be disabled.
116 Returns
117 -------
118 visitInfo : `lsst.afw.image.VisitInfo`
119 `~lsst.afw.image.VisitInfo` derived from the supplied
120 `~astro_metadata_translator.ObservationInfo`.
121 """
122 argDict = dict()
124 # Map the translated information into a form suitable for VisitInfo
125 if obsInfo.exposure_time is not None:
126 argDict["exposureTime"] = obsInfo.exposure_time.to_value("s")
127 if obsInfo.dark_time is not None:
128 argDict["darkTime"] = obsInfo.dark_time.to_value("s")
129 argDict["exposureId"] = obsInfo.detector_exposure_id
131 # VisitInfo uses the middle of the observation for the date
132 if obsInfo.datetime_begin is not None and obsInfo.datetime_end is not None:
133 tdelta = obsInfo.datetime_end - obsInfo.datetime_begin
134 middle = obsInfo.datetime_begin + 0.5*tdelta
136 # DateTime uses nanosecond resolution, regardless of the resolution
137 # of the original date
138 middle.precision = 9
139 # isot is ISO8601 format with "T" separating date and time and no
140 # time zone
141 argDict["date"] = DateTime(middle.tai.isot, DateTime.TAI)
143 # Derive earth rotation angle from UT1 (being out by a second is not
144 # a big deal given the uncertainty over exactly what part of the
145 # observation we are needing it for).
146 # ERFA needs a UT1 time split into two floats
147 # We ignore any problems with DUT1 not being defined for now.
148 try:
149 # Catch any warnings about the time being in the future
150 # since there is nothing we can do about that for simulated
151 # data and it tells us nothing for data from the past.
152 with warnings.catch_warnings():
153 warnings.simplefilter("ignore", category=astropy.utils.exceptions.AstropyWarning)
154 ut1time = middle.ut1
155 except iers.IERSRangeError:
156 ut1time = middle
158 era = erfa.era00(ut1time.jd1, ut1time.jd2)
159 argDict["era"] = era * radians
160 else:
161 argDict["date"] = DateTime()
163 # Coordinates
164 if obsInfo.tracking_radec is not None:
165 icrs = obsInfo.tracking_radec.transform_to("icrs")
166 argDict["boresightRaDec"] = SpherePoint(icrs.ra.degree,
167 icrs.dec.degree, units=degrees)
169 altaz = obsInfo.altaz_begin
170 if altaz is not None:
171 argDict["boresightAzAlt"] = SpherePoint(altaz.az.degree,
172 altaz.alt.degree, units=degrees)
174 argDict["boresightAirmass"] = obsInfo.boresight_airmass
176 if obsInfo.boresight_rotation_angle is not None:
177 argDict["boresightRotAngle"] = obsInfo.boresight_rotation_angle.degree*degrees
179 if obsInfo.boresight_rotation_coord is not None:
180 rotType = RotType.UNKNOWN
181 if obsInfo.boresight_rotation_coord == "sky":
182 rotType = RotType.SKY
183 argDict["rotType"] = rotType
185 # Weather and Observatory Location
186 temperature = float("nan")
187 if obsInfo.temperature is not None:
188 temperature = obsInfo.temperature.to_value("deg_C", astropy.units.temperature())
189 pressure = float("nan")
190 if obsInfo.pressure is not None:
191 pressure = obsInfo.pressure.to_value("Pa")
192 relative_humidity = float("nan")
193 if obsInfo.relative_humidity is not None:
194 relative_humidity = obsInfo.relative_humidity
195 argDict["weather"] = Weather(temperature, pressure, relative_humidity)
197 if obsInfo.location is not None:
198 geolocation = obsInfo.location.to_geodetic()
199 argDict["observatory"] = Observatory(geolocation.lon.degree*degrees,
200 geolocation.lat.degree*degrees,
201 geolocation.height.to_value("m"))
203 for key in list(argDict.keys()): # use a copy because we may delete items
204 if argDict[key] is None:
205 if log is not None:
206 log.warn("argDict[{}] is None; stripping".format(key, argDict[key]))
207 del argDict[key]
209 return VisitInfo(**argDict)