SSB-42: minor fix, and add function to list for all the target station

present in the observation path

CAL/CalibrationCommon/lib/utils.py

@@ -28,6 +28,7 @@ def match_holography_beam_specification_file_with_observation(path):
     observation_list = HolographyObservation.list_observations_in_path(path)
     matched_observation_bsf_pair = []
     for bsf_file in bsf_files:
+        bsf_file.read_file()
         for observation in observation_list:
             if is_observation_in_range(observation.start_datetime,
                                        observation.end_datetime,
@@ -39,3 +40,10 @@ def match_holography_beam_specification_file_with_observation(path):
     return matched_observation_bsf_pair
 
 
+def list_all_target_stations(observation_path):
+    bsf_files = HolographySpecification.list_bsf_files_in_path(observation_path)
+    target_station_name_set = set()
+    for bsf_file in bsf_files:
+        bsf_file.read_file()
+        target_station_name_set.update(bsf_file.target_station_names)
+    return list(target_station_name_set)
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