diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index 5ad96673324f0f0de6f68e4dacdb835c49a884d7..6225ce5bfdb76b4f0cca553c8c19ba6077904639 100644
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -32,7 +32,7 @@ class Instrument:
     SCS = ForEachSC.indices()
     MOSAS = ForEachMOSA.indices()
 
-    def __init__(self, size=2592000, dt=0.3, t0=0,
+    def __init__(self, size=2592000, dt=1/4, t0=0,
                  # Inter-spacecraft propagation
                  orbits=None, gws=None, glitches=None, interpolation=('lagrange', 31),
                  # Lasers
@@ -46,7 +46,7 @@ class Instrument:
                  # Pseudo-ranging
                  ranging_biases=0, ranging_asds=3E-9,
                  # Physics simulation sampling and filtering
-                 physics_upsampling=10, aafilter=('kaiser', 240, 0.3, 1.35)):
+                 physics_upsampling=4, aafilter=('kaiser', 240, 1.1, 2.9)):
         """Initialize an instrumental simulation.
 
         Args: