Source code for legacypipe.decam

from __future__ import print_function
import numpy as np

import astropy.time

from legacypipe.image import LegacySurveyImage, CP_DQ_BITS

Code specific to images from the Dark Energy Camera (DECam).

[docs]class DecamImage(LegacySurveyImage): ''' A LegacySurveyImage subclass to handle images from the Dark Energy Camera, DECam, on the Blanco telescope. ''' def __init__(self, survey, t): super(DecamImage, self).__init__(survey, t) # Adjust zeropoint for exposure time self.ccdzpt += 2.5 * np.log10(self.exptime)
[docs] def read_invvar(self, **kwargs): return self.read_invvar_clipped(**kwargs)
glowmjd = astropy.time.Time('2014-08-01').utc.mjd
[docs] def get_good_image_subregion(self): x0,x1,y0,y1 = None,None,None,None # Handle 'glowing' edges in DES r-band images # aww yeah if == 'r' and ( ('DES' in self.imgfn) or ('COSMOS' in self.imgfn) or (self.mjdobs < DecamImage.glowmjd)): # Northern chips: drop 100 pix off the bottom if 'N' in self.ccdname: print('Clipping bottom part of northern DES r-band chip') y0 = 100 else: # Southern chips: drop 100 pix off the top print('Clipping top part of southern DES r-band chip') y1 = self.height - 100 # Clip the bad half of chip S7. # The left half is OK. if self.ccdname == 'S7': print('Clipping the right half of chip S7') x1 = 1023 return x0,x1,y0,y1
[docs] def remap_dq(self, dq, hdr): ''' Called by get_tractor_image() to map the results from read_dq into a bitmask. ''' primhdr = self.read_primary_header(self.dqfn) plver = primhdr['PLVER'] if decam_has_dq_codes(plver): dq = self.remap_dq_cp_codes(dq, hdr) else: from legacypipe.image import CP_DQ_BITS dq = dq.astype(np.int16) # Un-set the SATUR flag for pixels that also have BADPIX set. bothbits = CP_DQ_BITS['badpix'] | CP_DQ_BITS['satur'] I = np.flatnonzero((dq & bothbits) == bothbits) if len(I): print('Warning: un-setting SATUR for', len(I), 'pixels with SATUR and BADPIX set.') dq.flat[I] &= ~CP_DQ_BITS['satur'] assert(np.all((dq & bothbits) != bothbits)) return dq
def decam_has_dq_codes(plver): from distutils.version import StrictVersion # The format of the DQ maps changed as of version 3.5.0 of the # Community Pipeline. Handle that here... plver = plver.strip() plver = plver.replace('V','') plver = plver.replace('DES ', '') plver = plver.replace('+1', 'a1') return StrictVersion(plver) >= StrictVersion('3.5.0')