diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index a8a7dd2b4521c5a25e8a6644e4d66353fd596f67..d4e36aab8df8086fd072df37f8d36fd35a99a033 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -679,8 +679,8 @@ class Instrument:
 
         # Prepare common interpolation method
         times = orbitf.attrs['t0'] + np.arange(orbitf.attrs['size']) * orbitf.attrs['dt']
-        interpolate = lambda data, t: InterpolatedUnivariateSpline(times, data, k=3, ext='raise')(t)
-        int_interpolate = lambda data, t: InterpolatedUnivariateSpline(times, data, k=3, ext='raise').antiderivative()(t)
+        interpolate = lambda data, t: InterpolatedUnivariateSpline(times, data, k=5, ext='raise')(t)
+        int_interpolate = lambda data, t: InterpolatedUnivariateSpline(times, data, k=5, ext='raise').antiderivative()(t)
         link_index = {'12': 0, '23': 1, '31': 2, '13': 3, '32': 4, '21': 5}
         sc_index = {'1': 0, '2': 1, '3': 2}