Task SSB-42: Added a definition for the numpy coordinate type

CAL/CalibrationCommon/lib/datacontainers/holography_dataset.py

@@ -229,7 +229,10 @@ class HolographyDataset():
         #self.ra_dec = numpy.zeros((n_frequencies, n_beamlets),
         #                           dtype=coordinate_type)
         self.ra_dec = dict()
-        
+        coordinate_type = numpy.dtype([('RA', numpy.float64), 
+                                       ('DEC', numpy.float64),
+                                       ('EPOCH', 'S10')])
+             
         for frequency in self.frequencies:
             frequency_string = str(frequency)
             if frequency not in self.ra_dec: