Index: ammosreader/PDW.py
===================================================================
--- ammosreader/PDW.py	(revision dbcb2557515b7ecdf063c8ee0f02e58933d3a560)
+++ ammosreader/PDW.py	(revision 5d039b8e61a151f3825d977516c4463113fc9919)
@@ -223,7 +223,7 @@
 
     def to_json(self):
-        return {'TIMEOFARRIVAL': self.time_of_arrival,
+        return {'time of arrival': self.time_of_arrival,
                 'FORMATIDENTIFIER': self.pdw_format_identifier,
-                'CENTERFREQUENCY': self.center_frequency,
+                'center frequency': self.center_frequency,
                 'VALID': self.is_valid,
                 'PULSE': self.is_pulse,
Index: ammosreader/PPDWContainer.py
===================================================================
--- ammosreader/PPDWContainer.py	(revision dbcb2557515b7ecdf063c8ee0f02e58933d3a560)
+++ ammosreader/PPDWContainer.py	(revision 5d039b8e61a151f3825d977516c4463113fc9919)
@@ -29,6 +29,6 @@
         for index, current_pdw in enumerate(self.signals[1:]):
             pulse_dict[index+1] = current_pdw.to_json()
-            pulse_dict[index]["TIMEDELTA"] = current_pdw.time_of_arrival - pulse_dict[index]["TIMEOFARRIVAL"]
-        pulse_dict[index+1]["TIMEDELTA"] = 0
+            pulse_dict[index]["dtoa"] = (current_pdw.time_of_arrival - pulse_dict[index]["time of arrival"]).item()/1000.0
+        pulse_dict[index+1]["dtoa"] = 0.0  # np.timedelta64(0, 'us')
         return pulse_dict
 
@@ -60,8 +60,8 @@
                 'STARTTIME': str(self.start_time()),
                 'ENDTIME': str(self.end_time()),
-                # 'CENTERFREQUENCIES': self.center_frequencies(),
-                'CHANNELS': self.channels()
-                # 'MODULATIONS': self.modulations(),
-                # 'BANDWIDTHS': self.bandwidths()
+                'CENTERFREQUENCIES': self.center_frequencies(),
+                'CHANNELS': self.channels(),
+                'MODULATIONS': self.modulations(),
+                'BANDWIDTHS': self.bandwidths()
                 }