def __init__(self, header):
super(self.__class__, self).__init__(header)
self.mop_keywords = ['NAXIS1',
'NAXIS2',
'CRPIX1',
'CRPIX2',
'CRVAL1',
'CRVAL2',
'PIXSCALE',
'EXPTIME',
'EXPNUM',
'RDNOISE',
'PHPADU',
'CHIPNUM',
'DETECTOR',
'MJD-OBSC']
self.mop_comments = {'MJD-OBSC': "MJD at observation center time"}
self._DET_X_CEN = 11604.5
self._DET_Y_CEN = 9681
try:
self.wcs = WCS(header)
except:
self.wcs = None
for keyword in self.mop_keywords:
try:
comment = self.comments[keyword]
except:
comment = self.mop_comments.get(keyword, None)
try:
self[keyword] = (self.__getattribute__(keyword.lower().replace("-", "_")), comment)
except Exception as ex:
logging.debug("Failed to build mopkeyword: {} -> {} using default".format(keyword, ex))
pass
for keyword in list(self.keys()):
if keyword not in self.mop_keywords:
try:
self.__delitem__(keyword)
except:
pass
self['MOP_VER'] = 1.21
def __init__(self, header):
super(self.__class__, self).__init__(header)
self.mop_keywords = ['NAXIS1',
'NAXIS2',
'CRPIX1',
'CRPIX2',
'CRVAL1',
'CRVAL2',
'PIXSCALE',
'EXPTIME',
'EXPNUM',
'RDNOISE',
'PHPADU',
'CHIPNUM',
'DETECTOR',
'MJD-OBSC']
self.mop_comments = {'MJD-OBSC': "MJD at observation center time"}
self._DET_X_CEN = 11604.5
self._DET_Y_CEN = 9681
try:
self.wcs = WCS(header)
except:
self.wcs = None
for keyword in self.mop_keywords:
try:
comment = self.comments[keyword]
except:
comment = self.mop_comments.get(keyword, None)
try:
self[keyword] = (self.__getattribute__(keyword.lower().replace("-", "_")), comment)
except Exception as ex:
logging.debug("Failed to build mopkeyword: {} -> {} using default".format(keyword, ex))
pass
for keyword in self.keys():
if keyword not in self.mop_keywords:
try:
self.__delitem__(keyword)
except:
pass
self['MOP_VER'] = 1.21
class MOPHeader(fits.Header):
"""
MOPHeader creates a fits.Header object that is derived from an input image (only works for MegaPrime right now)
but with some keyword values modified to provide the correct values to down-stream processing.
Currently for MegaPrime the only major use of mopheader is to correct the FITS header expsoure time.
"""
def __init__(self, header):
super(self.__class__, self).__init__(header)
self.mop_keywords = ['NAXIS1',
'NAXIS2',
'CRPIX1',
'CRPIX2',
'CRVAL1',
'CRVAL2',
'PIXSCALE',
'EXPTIME',
'EXPNUM',
'RDNOISE',
'PHPADU',
'CHIPNUM',
'DETECTOR',
'MJD-OBSC']
self.mop_comments = {'MJD-OBSC': "MJD at observation center time"}
self._DET_X_CEN = 11604.5
self._DET_Y_CEN = 9681
try:
self.wcs = WCS(header)
except:
self.wcs = None
for keyword in self.mop_keywords:
try:
comment = self.comments[keyword]
except:
comment = self.mop_comments.get(keyword, None)
try:
self[keyword] = (self.__getattribute__(keyword.lower().replace("-", "_")), comment)
except Exception as ex:
logging.debug("Failed to build mopkeyword: {} -> {} using default".format(keyword, ex))
pass
for keyword in list(self.keys()):
if keyword not in self.mop_keywords:
try:
self.__delitem__(keyword)
except:
pass
self['MOP_VER'] = 1.21
def writeto(self, filename, **kwargs):
"""
Write the header to a fits file.
:param filename:
:return:
"""
fits.PrimaryHDU(header=self).writeto(filename, output_verify='ignore', **kwargs)
@property
def crpix1(self):
return round(self.crpix[0], 2)
@property
def crpix2(self):
return round(self.crpix[1], 2)
@property
def crval1(self):
return round(self.crval[0], 5)
@property
def crval2(self):
return round(self.crval[1], 5)
@property
def crpix(self):
"""
The location of the reference coordinate in the pixel frame.
First simple respond with the header values, if they don't exist try usnig the DETSEC values
@rtype: float, float
"""
try:
return self.wcs.crpix1, self.wcs.crpix2
except Exception as ex:
logging.debug("Couldn't get CRPIX from WCS: {}".format(ex))
logging.debug("Switching to use DATASEC for CRPIX value computation.")
try:
(x1, x2), (y1, y2) = util.get_pixel_bounds_from_datasec_keyword(self['DETSEC'])
dx = float(self['NAXIS1'])
dy = float(self['NAXIS2'])
except KeyError as ke:
raise KeyError("Header missing keyword: {}, required for CRPIX[12] computation".format(ke.args[0]))
crpix1 = self._DET_X_CEN - (x1 + x2) / 2. + dx / 2.
crpix2 = self._DET_Y_CEN - (y1 + y2) / 2. + dy / 2.
return crpix1, crpix2
@property
def mjd_obsc(self):
"""Given a CFHT Megaprime image header compute the center of exposure.
This routine uses the calibration provide by Richard Wainscoat:
From: Richard Wainscoat <*****@*****.**>
Subject: Fwd: timing for MegaCam
Date: April 24, 2015 at 7:23:09 PM EDT
To: David Tholen <*****@*****.**>
Looks like the midpoint of the exposure is now UTCEND - 0.73 sec - (exposure time / 2 )
Wobble on the 0.73 sec is +/- 0.15 sec.
@rtype : float
"""
# TODO Check if this exposure was taken afer or before correction needed.
try:
utc_end = self['UTCEND']
exposure_time = float(self['EXPTIME'])
date_obs = self['DATE-OBS']
except KeyError as ke:
raise KeyError("Header missing keyword: {}, required for MJD-OBSC computation".format(ke.args[0]))
utc_end = Time(date_obs + "T" + utc_end)
utc_cen = utc_end - TimeDelta(0.73, format='sec') - TimeDelta(exposure_time / 2.0, format='sec')
return round(utc_cen.mjd, 7)
@property
def crval(self):
"""
Get the world coordinate of the reference pixel.
@rtype: float, float
"""
try:
return self.wcs.crval1, self.wcs.crval2
except Exception as ex:
logging.debug("Couldn't get CRVAL from WCS: {}".format(ex))
logging.debug("Trying RA/DEC values")
try:
return (float(self['RA-DEG']),
float(self['DEC-DEG']))
except KeyError as ke:
KeyError("Can't build CRVAL1/2 missing keyword: {}".format(ke.args[0]))
@property
def pixscale(self):
"""Return the pixel scale of the detector, in arcseconds.
This routine first attempts to compute the size of a pixel using the WCS. Then looks for PIXSCAL in header.
@return: pixscal
@rtype: float
"""
try:
(x, y) = self['NAXIS1'] / 2.0, self['NAXIS2'] / 2.0
p1 = SkyCoord(*self.wcs.xy2sky(x, y) * units.degree)
p2 = SkyCoord(*self.wcs.xy2sky(x + 1, y + 1) * units.degree)
return round(p1.separation(p2).to(units.arcsecond).value / math.sqrt(2), 3)
except Exception as ex:
logging.debug("Failed to compute PIXSCALE using WCS: {}".format(ex))
return float(self['PIXSCAL'])
@property
def chipnum(self):
return int(self['EXTVER']) + 1
@property
def phpadu(self):
"""
@rtype: float
@return: The CCD gain
"""
return round(float(self['GAIN']), 2)
@property
def detector(self):
"""
@rtype: basestring
:return: The DETECTOR keyword value
"""
return self.get('DETECTOR', self['INSTRUME'])
class MOPHeader(fits.Header):
"""
MOPHeader creates a fits.Header object that is derived from an input image (only works for MegaPrime right now)
but with some keyword values modified to provide the correct values to down-stream processing.
Currently for MegaPrime the only major use of mopheader is to correct the FITS header expsoure time.
"""
def __init__(self, header):
super(self.__class__, self).__init__(header)
self.mop_keywords = ['NAXIS1',
'NAXIS2',
'CRPIX1',
'CRPIX2',
'CRVAL1',
'CRVAL2',
'PIXSCALE',
'EXPTIME',
'EXPNUM',
'RDNOISE',
'PHPADU',
'CHIPNUM',
'DETECTOR',
'MJD-OBSC']
self.mop_comments = {'MJD-OBSC': "MJD at observation center time"}
self._DET_X_CEN = 11604.5
self._DET_Y_CEN = 9681
try:
self.wcs = WCS(header)
except:
self.wcs = None
for keyword in self.mop_keywords:
try:
comment = self.comments[keyword]
except:
comment = self.mop_comments.get(keyword, None)
try:
self[keyword] = (self.__getattribute__(keyword.lower().replace("-", "_")), comment)
except Exception as ex:
logging.debug("Failed to build mopkeyword: {} -> {} using default".format(keyword, ex))
pass
for keyword in self.keys():
if keyword not in self.mop_keywords:
try:
self.__delitem__(keyword)
except:
pass
self['MOP_VER'] = 1.21
def writeto(self, filename, **kwargs):
"""
Write the header to a fits file.
:param filename:
:return:
"""
fits.PrimaryHDU(header=self).writeto(filename, output_verify='ignore', **kwargs)
@property
def crpix1(self):
return round(self.crpix[0], 2)
@property
def crpix2(self):
return round(self.crpix[1], 2)
@property
def crval1(self):
return round(self.crval[0], 5)
@property
def crval2(self):
return round(self.crval[1], 5)
@property
def crpix(self):
"""
The location of the reference coordinate in the pixel frame.
First simple respond with the header values, if they don't exist try usnig the DETSEC values
@rtype: float, float
"""
try:
return self.wcs.crpix1, self.wcs.crpix2
except Exception as ex:
logging.debug("Couldn't get CRPIX from WCS: {}".format(ex))
logging.debug("Switching to use DATASEC for CRPIX value computation.")
try:
(x1, x2), (y1, y2) = util.get_pixel_bounds_from_datasec_keyword(self['DETSEC'])
dx = float(self['NAXIS1'])
dy = float(self['NAXIS2'])
except KeyError as ke:
raise KeyError("Header missing keyword: {}, required for CRPIX[12] computation".format(ke.args[0]))
crpix1 = self._DET_X_CEN - (x1 + x2) / 2. + dx / 2.
crpix2 = self._DET_Y_CEN - (y1 + y2) / 2. + dy / 2.
return crpix1, crpix2
@property
def mjd_obsc(self):
"""Given a CFHT Megaprime image header compute the center of exposure.
This routine uses the calibration provide by Richard Wainscoat:
From: Richard Wainscoat <*****@*****.**>
Subject: Fwd: timing for MegaCam
Date: April 24, 2015 at 7:23:09 PM EDT
To: David Tholen <*****@*****.**>
Looks like the midpoint of the exposure is now UTCEND - 0.73 sec - (exposure time / 2 )
Wobble on the 0.73 sec is +/- 0.15 sec.
@rtype : float
"""
# TODO Check if this exposure was taken afer or before correction needed.
try:
utc_end = self['UTCEND']
exposure_time = float(self['EXPTIME'])
date_obs = self['DATE-OBS']
except KeyError as ke:
raise KeyError("Header missing keyword: {}, required for MJD-OBSC computation".format(ke.args[0]))
utc_end = Time(date_obs + "T" + utc_end)
utc_cen = utc_end - TimeDelta(0.73, format='sec') - TimeDelta(exposure_time / 2.0, format='sec')
return round(utc_cen.mjd, 7)
@property
def crval(self):
"""
Get the world coordinate of the reference pixel.
@rtype: float, float
"""
try:
return self.wcs.crval1, self.wcs.crval2
except Exception as ex:
logging.debug("Couldn't get CRVAL from WCS: {}".format(ex))
logging.debug("Trying RA/DEC values")
try:
return (float(self['RA-DEG']),
float(self['DEC-DEG']))
except KeyError as ke:
KeyError("Can't build CRVAL1/2 missing keyword: {}".format(ke.args[0]))
@property
def pixscale(self):
"""Return the pixel scale of the detector, in arcseconds.
This routine first attempts to compute the size of a pixel using the WCS. Then looks for PIXSCAL in header.
@return: pixscal
@rtype: float
"""
try:
(x, y) = self['NAXIS1'] / 2.0, self['NAXIS2'] / 2.0
p1 = SkyCoord(*self.wcs.xy2sky(x, y) * units.degree)
p2 = SkyCoord(*self.wcs.xy2sky(x + 1, y + 1) * units.degree)
return round(p1.separation(p2).to(units.arcsecond).value / math.sqrt(2), 3)
except Exception as ex:
logging.debug("Failed to compute PIXSCALE using WCS: {}".format(ex))
return float(self['PIXSCAL'])
@property
def chipnum(self):
return int(self['EXTVER']) + 1
@property
def phpadu(self):
"""
@rtype: float
@return: The CCD gain
"""
return round(float(self['GAIN']), 2)
@property
def detector(self):
"""
@rtype: basestring
:return: The DETECTOR keyword value
"""
return self.get('DETECTOR', self['INSTRUME'])
