Merge pull request #218 from LSSTDESC/u/jchiang/roll-back_observatory…

…_setting

undo the changes to set the GalSimInterpreter._observatory attribute

python/desc/imsim/ImageSimulator.py

@@ -15,7 +15,7 @@
 from lsst.sims.photUtils import BandpassDict
 from lsst.sims.GalSimInterface import make_galsim_detector
 from lsst.sims.GalSimInterface import make_gs_interpreter
-from lsst.sims.GalSimInterface import LSSTCameraWrapper, LsstObservatory
+from lsst.sims.GalSimInterface import LSSTCameraWrapper
 from .imSim import read_config, parsePhoSimInstanceFile, add_cosmic_rays,\
     add_treering_info, get_logger, TracebackDecorator
 from .bleed_trails import apply_channel_bleeding
@@ -100,10 +100,6 @@ def __init__(self, instcat, psf, numRows=None, config=None, seed=267,
         self.gs_obj_dict = sources[1]
         self.apply_sensor_model = apply_sensor_model
         self.file_id = file_id
-        # Create an LsstObservatory object to be shared among the
-        # GalSimInterpeter objects to avoid the computational cost in
-        # making one for each.
-        self.lsstObservatory = LsstObservatory()
         self._make_gs_interpreters(seed, sensor_list, file_id)
         self.log_level = log_level
         self.logger = get_logger(self.log_level, name='ImageSimulator')
@@ -154,7 +150,6 @@ def _make_gs_interpreters(self, seed, sensor_list, file_id):
                                       apply_sensor_model=self.apply_sensor_model,
                                       bf_strength=self.config['ccd']['bf_strength'])
 
-            self.gs_interpreters[det_name]._observatory = self.lsstObservatory
             self.gs_interpreters[det_name].sky_bg_per_pixel \
                 = noise_and_background.sky_counts(det_name)
             self.gs_interpreters[det_name].setPSF(PSF=self.psf)