diff --git a/keogram.py b/keogram.py
new file mode 100755
index 0000000..10ff9b0
--- /dev/null
+++ b/keogram.py
@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+from __future__ import print_function
+import glob
+import numpy as np
+from stvid.stio import fourframe
+import configparser
+import argparse
+import os
+import matplotlib.pyplot as plt
+import matplotlib.dates as mdates
+from astropy.time import Time
+
+def generate_keogram(path):
+    # Get files
+    fnames = sorted(glob.glob(os.path.join(path, "processed/2*.fits")))
+
+    # Allocate arrays
+    nx = len(fnames)
+    ny = cfg.getint('Camera', 'camera_y')
+    ixmid = cfg.getint('Camera', 'camera_x')//2
+    keogram = np.zeros(nx*ny).reshape(ny, nx)
+    mjds = np.zeros(nx)
+    
+    # Get data
+    for i, fname in enumerate(fnames):
+        if i%10==0:
+            print(i, fname)
+
+        # Read file
+        ff = fourframe(fname)
+
+        # Extract data
+        keogram[:, i] = ff.zavg[:, ixmid]
+        mjds[i] = ff.mjd
+
+    # Save npy arrays
+    np.save(os.path.join(path, "mjds"), mjds)
+    np.save(os.path.join(path, "keogram"), keogram)
+
+
+if __name__ == "__main__":
+    # Read commandline options
+    conf_parser = argparse.ArgumentParser(description='Process captured' +
+                                                      ' video frames.')
+    conf_parser.add_argument("-c", "--conf_file",
+                             help="Specify configuration file. If no file" +
+                             " is specified 'configuration.ini' is used.",
+                             metavar="FILE")
+    conf_parser.add_argument("-d", "--directory",
+                             help="Specify directory of observations. If no" +
+                             " directory is specified parent will be used.",
+                             metavar='DIR', dest='file_dir', default=".")
+
+    args = conf_parser.parse_args()
+
+    # Process commandline options and parse configuration
+    cfg = configparser.ConfigParser(inline_comment_prefixes=('#', ';'))
+    if args.conf_file:
+        cfg.read([args.conf_file])
+    else:
+        cfg.read('configuration.ini')
+
+    # Generate keogram is it does not exist
+    if not os.path.exists(os.path.join(args.file_dir, "keogram.npy")):
+        generate_keogram(args.file_dir)
+
+    # Load data
+    keogram = np.load(os.path.join(args.file_dir, "keogram.npy"))
+    mjds = np.load(os.path.join(args.file_dir, "mjds.npy"))
+
+    # Time limits
+    tmin = mdates.date2num(Time(np.min(mjds), format="mjd").datetime)
+    tmax = mdates.date2num(Time(np.max(mjds), format="mjd").datetime)
+    
+    # Plot keogram
+    fig, ax = plt.subplots(figsize=(15, 5))
+    ax.imshow(np.log10(keogram), aspect="auto", origin="lower", cmap="magma", extent=[tmin, tmax, 0, 1])
+
+    ax.axes.get_yaxis().set_visible(False)
+    ax.xaxis_date()
+    date_format = mdates.DateFormatter("%F\n%H:%M:%S")
+    ax.xaxis.set_major_formatter(date_format)
+    fig.autofmt_xdate(rotation=0, ha="center")
+    
+    plt.tight_layout()
+    plt.savefig(os.path.join(args.file_dir, "keogram.png"))