from astrodata import astro_data_tag, astro_data_descriptor, returns_list, TagSet
from ..gemini import AstroDataGemini
from .. import gmu
[docs]
class AstroDataTrecs(AstroDataGemini):
__keyword_dict = dict(camera = 'OBSMODE',
disperser = 'GRATING',
exposure_time = 'OBJTIME',
focal_plane_mask = 'SLIT',
pupil_mask = 'PUPILIMA')
@staticmethod
def _matches_data(source):
return source[0].header.get('INSTRUME', '').upper() == 'TRECS'
@astro_data_tag
def _tag_instrument(self):
return TagSet(['TRECS'])
# override gemini-level "type_mode" because OBSMODE is used for something
# else in TReCS.
@astro_data_tag
def _type_mode(self):
if 'MIRROR' in self.phu.get('GRATING', '').upper():
return TagSet(['IMAGE'])
else:
return TagSet(['SPECT'])
[docs]
@astro_data_descriptor
def central_wavelength(self, asMicrometers=False, asNanometers=False,
asAngstroms=False):
"""
Returns the central wavelength in meters or specified units
Parameters
----------
asMicrometers : bool
If True, return the wavelength in microns
asNanometers : bool
If True, return the wavelength in nanometers
asAngstroms : bool
If True, return the wavelength in Angstroms
Returns
-------
float
The central wavelength setting
"""
unit_arg_list = [asMicrometers, asNanometers, asAngstroms]
if unit_arg_list.count(True) == 1:
# Just one of the unit arguments was set to True. Return the
# central wavelength in these units
if asMicrometers:
output_units = "micrometers"
if asNanometers:
output_units = "nanometers"
if asAngstroms:
output_units = "angstroms"
else:
# Either none of the unit arguments were set to True or more than
# one of the unit arguments was set to True. In either case,
# return the central wavelength in the default units of meters.
output_units = "meters"
disperser = self.disperser()
if disperser is None:
return None
if disperser == 'LowRes-10':
wave_in_microns = 10.5
elif disperser == 'LowRes-20':
wave_in_microns = 20.0
elif disperser.startswith('HighRes-10'):
wave_in_microns = self.phu.get('HRCENWL')
else:
return None
return gmu.convert_units('micrometers', wave_in_microns, output_units)
[docs]
@astro_data_descriptor
def detector_x_offset(self):
"""
Returns the offset from the reference position in pixels along
the positive x-direction of the detector
Returns
-------
float
The offset in pixels
"""
try:
return self.phu.get('POFFSET') / self.pixel_scale()
except TypeError: # either is None
return None
[docs]
@astro_data_descriptor
def detector_y_offset(self):
"""
Returns the offset from the reference position in pixels along
the positive y-direction of the detector
Returns
-------
float
The offset in pixels
"""
try:
return -self.phu.get('QOFFSET') / self.pixel_scale()
except TypeError: # either is None
return None
[docs]
@astro_data_descriptor
def dispersion(self, asMicrometers=False, asNanometers=False,
asAngstroms=False):
"""
Returns the dispersion in meters per pixel as a list (one value per
extension) or a float if used on a single-extension slice. It is
possible to control the units of wavelength using the input arguments.
Parameters
----------
asMicrometers : bool
If True, return the wavelength in microns
asNanometers : bool
If True, return the wavelength in nanometers
asAngstroms : bool
If True, return the wavelength in Angstroms
Returns
-------
list/float
The dispersion(s)
"""
# Look for the relevant, which we assume is in meters per pixel
unit_arg_list = [asMicrometers, asNanometers, asAngstroms]
if unit_arg_list.count(True) == 1:
# Just one of the unit arguments was set to True. Return the
# central wavelength in these units
if asMicrometers:
output_units = "micrometers"
if asNanometers:
output_units = "nanometers"
if asAngstroms:
output_units = "angstroms"
else:
# Either none of the unit arguments were set to True or more than
# one of the unit arguments was set to True. In either case,
# return the central wavelength in the default units of meters.
output_units = "meters"
disperser = self.disperser()
if disperser == 'LowRes-10':
dispersion = 0.022
elif disperser == 'LowRes-20':
dispersion = 0.033
elif disperser.startswith('HighRes-10'):
dispersion = 0.0019
else:
dispersion = None
return gmu.convert_units('micrometers', dispersion, output_units)
[docs]
@returns_list
@astro_data_descriptor
def gain(self):
"""
Returns the gain (electrons/ADU) for each extension
Returns
-------
list of floats/float
Gains used for the observation
"""
bias_level = self.phu.get('BIASLEVL', '')
if bias_level == '2':
return 214.0
elif bias_level == '1':
return 718.0
[docs]
@astro_data_descriptor
def pixel_scale(self):
"""
Returns the image scale in arcseconds per pixel
Returns
-------
float
the pixel scale
"""
return 0.089