diff --git a/CAL/CalibrationCommon/lib/datacontainers/holography_measurementset.py b/CAL/CalibrationCommon/lib/datacontainers/holography_measurementset.py
index 1fd95230ff47f91a2043748b0d0e27013251297d..5a624c66a934a3b3b1e1c13e00f70846bf77eb7a 100644
--- a/CAL/CalibrationCommon/lib/datacontainers/holography_measurementset.py
+++ b/CAL/CalibrationCommon/lib/datacontainers/holography_measurementset.py
@@ -173,9 +173,9 @@ class HolographyMeasurementSet(object):
                                                            n_polarizations], order='F')
             flags = flags.reshape([n_reference_stations, n_timestamps], order='F')
 
-
-            beams_crosscorrelations_array = numpy.empty([n_reference_stations, n_timestamps],
-                                                        dtype = data_sample_type)
+            beams_crosscorrelations_array = numpy.full([n_reference_stations, n_timestamps],
+                                                       fill_value=-999999.9,
+                                                       dtype = data_sample_type)
 
             for reference_station_index, reference_station_name in enumerate(reference_stations):
                 beams_crosscorrelations_array[reference_station_index, :]['t'] = timestamps