diff -r 406eb996a9cd -r a2355e871b23 generic.py
--- a/generic.py	Thu Mar 20 09:17:09 2014 +0200
+++ b/generic.py	Mon May 12 11:14:44 2014 +0300
@@ -98,8 +98,8 @@
             raw_stop_in_seconds = raw_start_in_seconds + duration
             raw_Data_Stop_Time.append(raw_stop_in_seconds)
             
-        self.variables['Raw_Data_Start_Time']= raw_Data_Start_Time
-        self.variables['Raw_Data_Stop_Time']= raw_Data_Stop_Time
+        self.variables['Raw_Data_Start_Time'] = raw_Data_Start_Time
+        self.variables['Raw_Data_Stop_Time'] = raw_Data_Stop_Time
     
         # Make a dictionary to match time scales and channels
         channel_timescales = []
@@ -376,6 +376,14 @@
     
     def get_dark_measurements(self):
         return None
+    
+    @property
+    def mean_time(self):
+        start_time = self.info['start_time']
+        stop_time = self.info['stop_time']
+        dt = stop_time - start_time
+        t_mean = start_time + dt / 2
+        return t_mean
 
 
 class Lidar_channel: