diff --git a/swash/processing/transmission.py b/swash/processing/transmission.py
new file mode 100644
index 0000000..b272a2d
--- /dev/null
+++ b/swash/processing/transmission.py
@@ -0,0 +1,71 @@
+import argparse
+import configparser
+import logging
+import pathlib
+
+import matplotlib.pyplot as plt
+import numpy as np
+import scipy.signal as sgl
+
+parser = argparse.ArgumentParser(description="Post-process swash output")
+parser.add_argument("-v", "--verbose", action="count", default=0)
+parser.add_argument("-c", "--config", default="config.ini")
+args = parser.parse_args()
+
+logging.basicConfig(level=max((10, 20 - 10 * args.verbose)))
+log = logging.getLogger("post")
+
+log.info("Starting post-processing")
+config = configparser.ConfigParser()
+config.read(args.config)
+
+inp = pathlib.Path(config.get("post", "inp"))
+root = pathlib.Path(config.get("swash", "out"))
+
+log.info(f"Reading data from '{inp}'")
+x = np.load(inp.joinpath("x.npy"))
+t = np.load(inp.joinpath("t.npy"))
+
+botl = np.load(inp.joinpath("botl.npy"))
+watl = np.load(inp.joinpath("watl.npy"))
+vel = np.load(inp.joinpath("vel.npy"))[0]
+
+t0 = np.linspace(23 * 60 + 8, 23 * 60 + 8 + 100, 5)
+
+# Plotting
+log.info("Plotting results")
+
+vlim = np.nanmin(np.maximum(watl, -botl)), np.nanmax(np.maximum(watl, -botl))
+
+fig_x, ax = plt.subplots(
+    len(t0), figsize=(10 / 2.54, 4 / 3 * 10 / 2.54), constrained_layout=True
+)
+i0 = np.argmin(np.abs(t * 1e-3 - t0[0]))
+for ax_x, t0_x in zip(ax, t0):
+    ax_x.plot(x, -botl, color="k")
+    i = np.argmin(np.abs(t * 1e-3 - t0_x))
+    ax_x.plot(
+        x,
+        np.maximum(watl[i, :], -botl),
+        color="#0066ff",
+    )
+    ax_x.axvline(-1450 + 1450 * ((t[i] - t[i0]) * 1e-3+5) / 100, color="k", alpha=0.2, lw=10)
+    ax_x.grid(color="k", alpha=0.2)
+    ax_x.set(ylabel="z (m)", ylim=vlim)
+    ax_x.text(
+        0.95,
+        0.95,
+        f"$T+{(t[i]-t[i0])*1e-3:.1f}s$",
+        horizontalalignment="right",
+        verticalalignment="top",
+        transform=ax_x.transAxes,
+    )
+    ax_x.autoscale(axis="x", tight=True)
+
+out = pathlib.Path(config.get("post", "out")).joinpath(f"trans")
+log.info(f"Saving plots in '{out}'")
+out.mkdir(parents=True, exist_ok=True)
+
+fig_x.savefig(out.joinpath("x.pdf"))
+
+log.info("Finished post-processing")