diff --git a/simulations/airshower_beacon_simulation/Makefile b/simulations/airshower_beacon_simulation/Makefile
index cbdbbec..7528db2 100644
--- a/simulations/airshower_beacon_simulation/Makefile
+++ b/simulations/airshower_beacon_simulation/Makefile
@@ -12,7 +12,7 @@ beacon:
 	./ac_show_signal_to_noise.py --no-show-plots --fig-dir=${FIG_DIR}
 
 clocks:
-	./ab_modify_clocks.py 15
+	./ab_modify_clocks.py 15 --gaussian
 
 phases:
 	./ba_measure_beacon_phase.py --no-show-plots --fig-dir=${FIG_DIR}
diff --git a/simulations/airshower_beacon_simulation/ab_modify_clocks.py b/simulations/airshower_beacon_simulation/ab_modify_clocks.py
index 413b03a..51c7e78 100755
--- a/simulations/airshower_beacon_simulation/ab_modify_clocks.py
+++ b/simulations/airshower_beacon_simulation/ab_modify_clocks.py
@@ -19,7 +19,17 @@ if __name__ == "__main__":
     from os import path
     import sys
 
-    max_clock_offset = 100 if len(sys.argv) < 2 else float(sys.argv[1]) # ns
+    from argparse import ArgumentParser
+
+    parser = ArgumentParser()
+    parser.add_argument('max_clock_offset', nargs='?', type=float, default=25, help='(Default: %(default)d)')
+    parser.add_argument('--uniform', action='store_const', const='uniform', dest='dist_type')
+    parser.add_argument('--gaussian',   action='store_const', const='gauss', dest='dist_type')
+    parser.set_defaults(dist_type='gauss')
+
+    args = parser.parse_args()
+
+    max_clock_offset = args.max_clock_offset # ns
     remake_clock_offsets = True
 
     seed = 12345
@@ -54,7 +64,7 @@ if __name__ == "__main__":
         if True:
             print(f"Modifying clocks upto {max_clock_offset}ns.")
             clock_offsets = np.zeros( N_antennas )
-            if not True: # uniform
+            if args.dist_type == 'uniform': # uniform
                 print("Uniform distribution")
                 clock_offsets = max_clock_offset * (2*rng.uniform(size=N_antennas) - 1)
             else: # normal