Add default -1.75° true North offset + associated warning

Ticket #88

sphere/IFS.py

@@ -462,6 +462,22 @@ def __new__(cls, path, log_level='info', sphere_handler=None):
 
         reduction._logger.info('Creating IFS reduction at path {}'.format(path))
 
+        #
+        # v1.4 - True North correction change
+        #
+        reduction._logger.warning('#################################################################')
+        reduction._logger.warning('Starting in the present version of the pipeline, the default     ')
+        reduction._logger.warning('-1.75° true North offset is automatically added to the derotation')
+        reduction._logger.warning('angles. The offset value can be modified in the configuration of ')
+        reduction._logger.warning('the reduction:                                                   ')
+        reduction._logger.warning('                                                                 ')
+        reduction._logger.warning('  >>> reduction.config[\'true_north\'] = xxx                     ')
+        reduction._logger.warning('                                                                 ')
+        reduction._logger.warning('To avoid any issues, make sure to:                               ')
+        reduction._logger.warning('  * either reprocess data previously processed with version <1.4 ')
+        reduction._logger.warning('  * or take into account the offset in your astrometric analysis ')
+        reduction._logger.warning('#################################################################')
+
         #
         # configuration
         #
@@ -1051,7 +1067,8 @@ def sort_frames(self):
         toolbox.compute_times(frames_info, logger=self._logger)
 
         # compute angles (ra, dec, parang)
-        ret = toolbox.compute_angles(frames_info, logger=self._logger)
+        true_north = self.config['true_north']
+        ret = toolbox.compute_angles(frames_info, true_north, logger=self._logger)
         if ret == sphere.ERROR:
             self._update_recipe_status('sort_frames', sphere.ERROR)
             self._status = sphere.FATAL

sphere/IRDIS/ImagingReduction.py

@@ -123,6 +123,22 @@ def __new__(cls, path, log_level='info', sphere_handler=None):
 
         reduction._logger.info('Creating IRDIS imaging reduction at path {}'.format(path))
 
+        #
+        # v1.4 - True North correction change
+        #
+        reduction._logger.warning('#################################################################')
+        reduction._logger.warning('Starting in the present version of the pipeline, the default     ')
+        reduction._logger.warning('-1.75° true North offset is automatically added to the derotation')
+        reduction._logger.warning('angles. The offset value can be modified in the configuration of ')
+        reduction._logger.warning('the reduction:                                                   ')
+        reduction._logger.warning('                                                                 ')
+        reduction._logger.warning('  >>> reduction.config[\'true_north\'] = xxx                     ')
+        reduction._logger.warning('                                                                 ')
+        reduction._logger.warning('To avoid any issues, make sure to:                               ')
+        reduction._logger.warning('  * either reprocess data previously processed with version <1.4 ')
+        reduction._logger.warning('  * or take into account the offset in your astrometric analysis ')
+        reduction._logger.warning('#################################################################')
+
         #
         # configuration
         #
@@ -674,7 +690,8 @@ def sort_frames(self):
         toolbox.compute_times(frames_info, logger=self._logger)
 
         # compute angles (ra, dec, parang)
-        ret = toolbox.compute_angles(frames_info, logger=self._logger)
+        true_north = self.config['true_north']        
+        ret = toolbox.compute_angles(frames_info, true_north, logger=self._logger)
         if ret == sphere.ERROR:
             self._update_recipe_status('sort_frames', sphere.ERROR)
             self._status = sphere.FATAL

sphere/IRDIS/SpectroReduction.py

@@ -747,7 +747,8 @@ def sort_frames(self):
         toolbox.compute_times(frames_info, logger=self._logger)
 
         # compute angles (ra, dec, parang)
-        ret = toolbox.compute_angles(frames_info, logger=self._logger)
+        true_north = self.config['true_north']
+        ret = toolbox.compute_angles(frames_info, true_north, logger=self._logger)
         if ret == sphere.ERROR:
             self._update_recipe_status('sort_frames', sphere.ERROR)
             self._status = sphere.FATAL

sphere/instruments/IFS.ini

@@ -20,6 +20,9 @@ default_center = (290//2, 290//2)
 # field orientation offset
 orientation_offset = 102
 
+# true North
+true_north = -1.75
+
 #
 # default reduction parameters
 #

sphere/instruments/IRDIS.ini

@@ -21,6 +21,9 @@ default_center = ((485, 520), (486, 508))
 # field orientation offset
 orientation_offset = 0
 
+# true North
+true_north = -1.75
+
 [calibration-spectro]
 
 # LRS parameters

sphere/toolbox.py

@@ -173,7 +173,7 @@ def compute_times(frames_info, logger=_log):
         frames_info['MJD']  = mjd
 
 
-def compute_angles(frames_info, logger=_log):
+def compute_angles(frames_info, true_north, logger=_log):
     '''
     Compute the various angles associated to frames: RA, DEC, parang,
     pupil offset, final derotation angle
@@ -183,9 +183,11 @@ def compute_angles(frames_info, logger=_log):
     frames_info : dataframe
         The data frame with all the information on science frames
 
+    true_north : float
+        True North offset correction, in degrees
+
     logger : logHandler object
         Log handler for the reduction. Default is root logger
-
     '''
 
     logger.debug('> compute angles')
@@ -262,11 +264,13 @@ def compute_angles(frames_info, logger=_log):
     #
     # Derotation angles
     #
-    # PA_on-sky = PA_detector + PARANGLE + True_North + PUP_OFFSET + INSTRUMENT_OFFSET
-    #  PUP_OFFSET = -135.99 ± 0.11
+    # PA_on-sky = PA_detector + PARANGLE + True_North + PUP_OFFSET + INSTRUMENT_OFFSET + TRUE_NORTH
+    #
+    #  PUP_OFFSET = +135.99 ± 0.11
     #  INSTRUMENT_OFFSET
-    #   IFS = +100.48 ± 0.10
-    #   IRD =    0.00 ± 0.00
+    #     * IFS = -100.48 ± 0.10
+    #     * IRD =    0.00 ± 0.00
+    #  TRUE_NORTH = -1.75 ± 0.08
     #
     if len(instrument) != 1:
         logger.error('Sequence is mixing different instruments: {0}'.format(instrument))
@@ -298,7 +302,7 @@ def compute_angles(frames_info, logger=_log):
     frames_info['PUPIL OFFSET'] = pupoff + instru_offset
 
     # final derotation value
-    frames_info['DEROT ANGLE'] = frames_info['PARANG'] + pupoff + instru_offset
+    frames_info['DEROT ANGLE'] = frames_info['PARANG'] + pupoff + instru_offset + true_north
 
     return sphere.SUCCESS