diff --git a/swash/config.ini b/swash/config.ini
index 0310686..171f312 100644
--- a/swash/config.ini
+++ b/swash/config.ini
@@ -17,3 +17,5 @@ out=out
 
 [post]
 out=out_post
+dt=0.25
+x0=125
diff --git a/swash/processing/post.py b/swash/processing/post.py
index dafe5c1..beac68b 100644
--- a/swash/processing/post.py
+++ b/swash/processing/post.py
@@ -1,5 +1,7 @@
 import configparser
 import pathlib
+import argparse
+import logging
 
 import numpy as np
 import pandas as pd
@@ -9,15 +11,25 @@ import scipy.signal as sgl
 from .read_swash import *
 
 
+parser = argparse.ArgumentParser(description="Pre-process bathymetry")
+parser.add_argument("-v", "--verbose", action="count", default=0)
+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("config.ini")
 
 cache = pathlib.Path(config.get("data", "out"))
 root = pathlib.Path(config.get("swash", "out"))
 
+log.info(f"Reading bathymetry from '{cache}'")
 bathy = pd.read_hdf(cache.joinpath("bathy.h5"), "bathy")
 n = bathy.index.size
 
+log.info(f"Reading swash output from '{root}'")
 botl = read_nohead_scalar(root.joinpath("botl.dat"), n)
 dep = np.maximum(0, read_nohead_scalar(root.joinpath("dep.dat"), n))
 vel = read_nohead_vect(root.joinpath("vel.dat"), n)
@@ -25,8 +37,9 @@ vel = read_nohead_vect(root.joinpath("vel.dat"), n)
 n_t = botl.shape[0]
 
 # Cospectral calculations
-pos_x = n // 10
-f = 1 / 0.25
+pos_x = config.getint("post", "x0")
+f = 1 / config.getfloat("post", "dt")
+log.info(f"Computing reflection coefficient at x={pos_x}")
 
 eta = (dep - botl)[n_t // 2 :, pos_x]
 u = vel[n_t // 2 :, 0, pos_x]
@@ -41,6 +54,7 @@ R = np.sqrt(
 )
 
 # Plotting
+log.info("Plotting results")
 fig, (ax_dep, ax_vel) = plt.subplots(2)
 
 ax_dep.plot((dep - botl)[:, pos_x], label="dep", color="#0066ff")
@@ -63,7 +77,10 @@ ax_r.set(ylim=(0, 1), xlabel="f (Hz)", ylabel="R")
 ax_r.grid()
 
 out = pathlib.Path(config.get("post", "out"))
+log.info(f"Saving plots in '{out}'")
 out.mkdir(exist_ok=True)
 
 fig.savefig(out.joinpath(f"{pos_x}.png"))
 fig_r.savefig(out.joinpath(f"R{pos_x}.png"))
+
+log.info("Finished post-processing")