MakeTestRawVisitInfo

class lsst.obs.test.MakeTestRawVisitInfo(log=None, doStripHeader=False)

Bases: lsst.obs.base.MakeRawVisitInfo

Make a VisitInfo from the FITS header of a test image.

Notes

Since the test data is extracted from LSST Sim data, this is a copy of MakeLsstSimRawVisitInfo (using a copy avoids undesireable dependencies).

Attributes Summary

observatory

Methods Summary

__call__(md, exposureId)	Construct a VisitInfo and strip associated data from the metadata.
altitudeFromZenithDistance(zd)	Convert zenith distance to altitude (lsst.afw.geom.Angle)
centigradeFromKelvin(tempK)	Convert temperature from Kelvin to Centigrade
defaultMetadata(value, defaultValue[, …])	Return the value if it is not NaN and within min/max, otherwise return defaultValue.
eraFromLstAndLongitude(lst, longitude)	Return an approximate Earth Rotation Angle (afw:Angle) computed from local sidereal time and longitude (both as afw:Angle; Longitude shares the afw:Observatory covention: positive values are E of Greenwich).
getDarkTime(argDict)	Get the darkTime from the DARKTIME keyword, else expTime, else NaN,
getDateAvg(md, exposureTime)	Return date at the middle of the exposure.
offsetDate(date, offsetSec)	Return a date offset by a specified number of seconds.
pascalFromMBar(mbar)	Convert pressure from millibars to Pascals
pascalFromMmHg(mmHg)	Convert pressure from mm Hg to Pascals
pascalFromTorr(torr)	Convert pressure from torr to Pascals
popAngle(md, key[, units])	Pop an lsst.afw.geom.Angle, whose metadata is in the specified units, with a default of Nan
popFloat(md, key)	Pop a float with a default of NaN.
popIsoDate(md, key[, timesys])	Pop a FITS ISO date as an lsst.daf.base.DateTime
popItem(md, key[, default])	Return an item of metadata.
popMjdDate(md, key[, timesys])	Get a FITS MJD date as an lsst.daf.base.DateTime.
setArgDict(md, argDict)	Set an argument dict for VisitInfo and pop associated metadata.

Attributes Documentation

observatory = -70.7494W, -30.2446N  2663

Methods Documentation

__call__(md, exposureId)

Construct a VisitInfo and strip associated data from the metadata.

Parameters

mdlsst.daf.base.PropertyList or lsst.daf.base.PropertySet

Metadata to pull from. Items that are used are stripped from the metadata (except TIMESYS, because it may apply to other keywords) if doStripHeader.

exposureIdint

exposure ID

Notes

The basic implementation sets date and exposureTime using typical values found in FITS files and logs a warning if neither can be set.

static altitudeFromZenithDistance(zd)

Convert zenith distance to altitude (lsst.afw.geom.Angle)

static centigradeFromKelvin(tempK)

Convert temperature from Kelvin to Centigrade

static defaultMetadata(value, defaultValue, minimum=None, maximum=None)

Return the value if it is not NaN and within min/max, otherwise return defaultValue.

Parameters

valuefloat

metadata value returned by popItem, popFloat, or popAngle

defaultValuefloat`

default value to use if the metadata value is invalid

minimumfloat

Minimum possible valid value, optional

maximumfloat

Maximum possible valid value, optional

Returns

float

The “validated” value.

static eraFromLstAndLongitude(lst, longitude)

Return an approximate Earth Rotation Angle (afw:Angle) computed from local sidereal time and longitude (both as afw:Angle; Longitude shares the afw:Observatory covention: positive values are E of Greenwich).

NOTE: if we properly compute ERA via UT1 a la DM-8053, we should remove this method.

getDarkTime(argDict)

Get the darkTime from the DARKTIME keyword, else expTime, else NaN,

If dark time is available then subclasses should call this method by putting the following in their __init__ method:

argDict['darkTime'] = self.getDarkTime(argDict)

Parameters

argdictdict

Dict of arguments.

Returns

float

Dark time, as inferred from the metadata.

getDateAvg(md, exposureTime)

Return date at the middle of the exposure.

Parameters

mdlsst.daf.base.PropertySet

Image metadata.

exposureTimefloat

Exposure time, in sec

Returns

dateAvglsst.daf.base.DateTime

Date at middle of the exposure, or lsst.daf.base.DateTime() if the metadata item TAI is not found.

offsetDate(date, offsetSec)

Return a date offset by a specified number of seconds.

datelsst.daf.base.DateTime

Date baseline to offset from.

offsetSecfloat

Offset, in seconds.

Returns

lsst.daf.base.DateTime

The offset date.

static pascalFromMBar(mbar)

Convert pressure from millibars to Pascals

static pascalFromMmHg(mmHg)

Convert pressure from mm Hg to Pascals

Notes

Could use the following, but astropy.units.cds is not fully compatible with Python 2 as of astropy 1.2.1 (see https://github.com/astropy/astropy/issues/5350#issuecomment-248612824): astropy.units.cds.mmHg.to(astropy.units.pascal, mmHg)

static pascalFromTorr(torr)

Convert pressure from torr to Pascals

popAngle(md, key, units=Unit('deg'))

Pop an lsst.afw.geom.Angle, whose metadata is in the specified units, with a default of Nan

The angle may be specified as a float or sexagesimal string with 1-3 fields.

Parameters

mdlsst.daf.base.PropertyList or PropertySet

Metadata to pull key from.

keystr

Key to read from md.

Returns

lsst.afw.geom.Angle

Value of the requested key as an angle; Angle(NaN) if the key is not found.

popFloat(md, key)

Pop a float with a default of NaN.

Parameters

mdlsst.daf.base.PropertyList or PropertySet

Metadata to pull key from.

keystr

Key to read.

Returns

float

Value of the requested key as a float; float(“nan”) if the key is not found.

popIsoDate(md, key, timesys=None)

Pop a FITS ISO date as an lsst.daf.base.DateTime

Parameters

mdlsst.daf.base.PropertyList or PropertySet

Metadata to pull key from.

keystr

Date key to read from md.

timesysstr

Time system as a string (not case sensitive), e.g. “UTC” or None; if None then look for TIMESYS (but do NOT pop it, since it may be used for more than one date) and if not found, use UTC.

Returns

lsst.daf.base.DateTime

Value of the requested date; DateTime() if the key is not found.

popItem(md, key, default=None)

Return an item of metadata.

The item is removed if doStripHeader is True.

Log a warning if the key is not found.

Parameters

mdlsst.daf.base.PropertyList or PropertySet

Metadata to pull key from and (optionally) remove.

keystr

Metadata key to extract.

defaultobject

Value to return if key not found.

Returns

object

The value of the specified key, using whatever type md.getScalar(key) returns.

popMjdDate(md, key, timesys=None)

Get a FITS MJD date as an lsst.daf.base.DateTime.

Parameters

mdlsst.daf.base.PropertyList or PropertySet

Metadata to pull key from.

keystr

Date key to read from md.

timesysstr

Time system as a string (not case sensitive), e.g. “UTC” or None; if None then look for TIMESYS (but do NOT pop it, since it may be used for more than one date) and if not found, use UTC.

Returns

lsst.daf.base.DateTime

Value of the requested date; DateTime() if the key is not found.

setArgDict(md, argDict)

Set an argument dict for VisitInfo and pop associated metadata.

Parameters

mdlsst.daf.base.PropertySet

Image metadata.

argDictdict

A dict of arguments for the lsst.afw.image.VisitInfo constructor. Updated by this call.

Returns

visitInfolsst.afw.image.VisitInfo

Visit information.