Task SSB-42: RA, DEC are stored in a tuple

CAL/CalibrationCommon/lib/datacontainers/holography_dataset.py

@@ -334,11 +334,13 @@ class HolographyDataset():
 
             # Data tables
             f[self.HDS_REFERENCE_STATION] = numpy.array(self.reference_stations,
-                                                 dtype=h5py.special_dtype(vlen = str))
+                                                 dtype = h5py.special_dtype(vlen = str))
 
             f[self.HDS_FREQUENCY] = self.frequencies
 
-            f[self.HDS_RA_DEC] = self.ra_dec
+            ra_dec_type = numpy.dtype([('RA', numpy.float64), 
+                                       ('DEC', numpy.float64)])
+            f[self.HDS_RA_DEC] = numpy.array(self.ra_dec, dtype = ra_dec_type)
 
             sample_type = numpy.dtype([
                 ('XX', numpy.complex64),