diff --git a/src/backscattering_analyzer/analyzer.py b/src/backscattering_analyzer/analyzer.py
index 89dbd4d..1d7525c 100644
--- a/src/backscattering_analyzer/analyzer.py
+++ b/src/backscattering_analyzer/analyzer.py
@@ -10,10 +10,10 @@ from numpy import loadtxt, array
 from scipy.io.matlab import loadmat
 
 # maths
-from numpy import mean, zeros, pi, sin, cos, arange, sqrt
+from numpy import mean, zeros, pi, sin, cos, arange, sqrt, where, real
 from scipy.signal import welch as psd
 from scipy.interpolate import CubicSpline
-
+from scipy.fft import fft, ifft, fftfreq
 
 class Analyzer:
     """
@@ -128,6 +128,7 @@ class Analyzer:
             ]
         )
         self.movement[1] -= mean(self.movement[1])
+        self.movement = self.movement[:,:-500000]
 
     def psd_signal(self, signal, fft_length=10):
         """
@@ -256,14 +257,8 @@ class Analyzer:
                 ]
             )
 
-            unpack = self.interpolate(
-                [factor_n, coupling_n, factor_d, coupling_d]
-            )
-            factor_n, coupling_n, factor_d, coupling_d = (
-                unpack[0],
-                unpack[1],
-                unpack[2],
-                unpack[3],
+            factor_n, coupling_n, factor_d, coupling_d = self.interpolate(
+                (factor_n, coupling_n, factor_d, coupling_d)
             )
 
             frequencies = factor_n[0]
@@ -273,8 +268,8 @@ class Analyzer:
                 * self.settings.power_in
                 / self.settings.power_out
                 * (
-                    coupling_n[1] * factor_n[1]
-                    + coupling_d[1] * factor_d[1]
+                    sqrt(coupling_n[1]) * sqrt(factor_n[1])
+                    + sqrt(coupling_d[1]) * sqrt(factor_d[1])
                 )
             )
         return array(
@@ -283,3 +278,14 @@ class Analyzer:
                 result,
             ]
         )
+
+    def low_pass_filter(self, signal, cutoff):
+        """
+        Cut higher frequencies than cutoff for a given temporal signal
+        """
+        sample_spacing = signal[0,1] - signal[0,0]
+        freq_signal = fft(signal[1])
+        frequencies = fftfreq(signal[1].shape[0], sample_spacing)
+        index_to_remove = where(abs(frequencies) > cutoff)
+        freq_signal[index_to_remove] = 0
+        return array([signal[0], real(ifft(freq_signal))])
diff --git a/src/backscattering_analyzer/settings.py b/src/backscattering_analyzer/settings.py
index 13c4a2c..ac6f00c 100644
--- a/src/backscattering_analyzer/settings.py
+++ b/src/backscattering_analyzer/settings.py
@@ -6,22 +6,20 @@ class Settings:
         self.version = "0.0.1"
         self.help = (
             "[main]display[/main] [option]\\[options][/option]"
-            "\n  [argument]-b --bench[argument]   [description]bench of the experiment[/description]"
-            "\n  [argument]-d --date[argument]    [description]date of the experiment[/description]"
-            "\n  [argument]-h --help[argument]    [description]print this help and exit[/description]"
-            "\n  [argument]-v --verbose[argument] [description]be verbose[/description]"
-            "\n  [argument]-V --version[argument] [description]print version number and exit[/description]"
+            "\n  [argument]-b --bench[/argument]   [description]bench of the experiment[/description]"
+            "\n  [argument]-d --date[/argument]    [description]date of the experiment[/description]"
+            "\n  [argument]-h --help[/argument]    [description]print this help and exit[/description]"
+            "\n  [argument]-v --verbose[/argument] [description]be verbose[/description]"
+            "\n  [argument]-V --version[/argument] [description]print version number and exit[/description]"
         )
         self.verbose = False
         self.bench = "SWEB"
         self.date = "2023_03_24"
         self.folder = Path("/home/demagny/data")
-        self.modelisation = "scatterCouplingO4.mat"
+        self.wavelength = 1.064e-6  # m
+
         self.calib_bench = 1.15
         self.calib_mirror = 1.15
-        self.wavelength = 1.064e-6  # m
-        self.power_in = 23  # W
-        self.power_out = 8e-3  # W
         self.scattering_factor = [1e-17, 0]  # parameter to change
 
         index = 0
@@ -112,6 +110,23 @@ class Settings:
                 pass
             index += 1
 
+        if self.date == "2023_03_24":
+            self.modelisation = "scatterCouplingO4.mat"
+            self.power_in = 23  # W
+            self.power_out = 8e-3  # W
+        elif self.date == "2023_12_21":
+            self.modelisation = "scatterCouplingMisalignSR.mat"
+            self.power_in = 12.1  # W
+            self.power_out = 8e-3  # W
+        elif self.date == "2024_01_21":
+            self.modelisation = "scatterCouplingMisalignSR.mat"
+            self.power_in = 12.1  # W
+            self.power_out = 8e-3  # W
+        else:
+            self.modelisation = "scatterCouplingO4.mat"
+            self.power_in = 23  # W
+            self.power_out = 8e-3  # W
+
     def bench_file(self):
         return self.folder / (
             "{bench}_{date}_ben.csv".format(