diff --git a/ogn/collect/celery.py b/ogn/collect/celery.py
index bc89364..dd8f289 100644
--- a/ogn/collect/celery.py
+++ b/ogn/collect/celery.py
@@ -9,7 +9,7 @@ from celery.signals import worker_init, worker_shutdown
 app = Celery('ogn.collect',
              broker='redis://localhost:6379/0',
              backend='redis://localhost:6379/0',
-             include=["ogn.collect.fetchddb"])
+             include=["ogn.collect.fetchddb", "ogn.collect.logbook"])
 
 DB_URI = 'sqlite:///beacons.db'
 
diff --git a/ogn/collect/fetchddb.py b/ogn/collect/fetchddb.py
index f228ed2..6b6fc57 100644
--- a/ogn/collect/fetchddb.py
+++ b/ogn/collect/fetchddb.py
@@ -36,6 +36,7 @@ def update_ddb_from_file():
         .delete()
 
     devices = get_ddb('ogn/custom_ddb.txt')
+    logger.debug("New Devices: %s" % str(devices))
 
     app.session.bulk_save_objects(devices)
     app.session.commit()
diff --git a/ogn/collect/logbook.py b/ogn/collect/logbook.py
index 59e835e..a0d51f1 100644
--- a/ogn/collect/logbook.py
+++ b/ogn/collect/logbook.py
@@ -1,6 +1,6 @@
 from __future__ import absolute_import
 
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from celery.utils.log import get_task_logger
 from ogn.collect.celery import app
@@ -16,14 +16,24 @@ logger = get_task_logger(__name__)
 
 @app.task
 def compute_takeoff_and_landing():
+    logger.info("Compute takeoffs and landings.")
+
     takeoff_speed = 30
     landing_speed = 30
 
-    # get last takeoff_landing time as starting point for the following search
+    # calculate the time where the computation starts
     last_takeoff_landing_query = app.session.query(func.max(TakeoffLanding.timestamp))
     last_takeoff_landing = last_takeoff_landing_query.one()[0]
     if last_takeoff_landing is None:
+        # if the table is empty
         last_takeoff_landing = datetime(2015, 1, 1, 0, 0, 0)
+    else:
+        # we get the beacons async. to be safe we delete takeoffs/landings from last 5 minutes and recalculate from then
+        # alternative: takeoff/landing has a primary key (timestamp,address)
+        last_takeoff_landing = last_takeoff_landing - timedelta(minutes=5)
+        app.session.query(TakeoffLanding) \
+            .filter(TakeoffLanding.timestamp > last_takeoff_landing) \
+            .delete()
 
     # make a query with current, previous and next position, so we can detect takeoffs and landings
     sq = app.session.query(
@@ -75,5 +85,9 @@ def compute_takeoff_and_landing():
 
     # ... and save them
     ins = insert(TakeoffLanding).from_select((TakeoffLanding.address, TakeoffLanding.timestamp, TakeoffLanding.latitude, TakeoffLanding.longitude, TakeoffLanding.track, TakeoffLanding.ground_speed, TakeoffLanding.altitude, TakeoffLanding.is_takeoff), takeoff_landing_query)
-    app.session.execute(ins)
+    result = app.session.execute(ins)
+    counter = result.rowcount
     app.session.commit()
+    logger.debug("New/recalculated takeoffs and landings: %s" % counter)
+
+    return counter
diff --git a/ogn/commands/logbook.py b/ogn/commands/logbook.py
index 7b2484a..35f079c 100644
--- a/ogn/commands/logbook.py
+++ b/ogn/commands/logbook.py
@@ -9,11 +9,21 @@ from sqlalchemy.sql.expression import true, false, label
 from ogn.model import Device, TakeoffLanding
 
 from ogn.commands.dbutils import session
+from ogn.collect.logbook import compute_takeoff_and_landing
 
 from manager import Manager
 manager = Manager()
 
 
+@manager.command
+def compute():
+    """Compute takeoffs and landings."""
+    print("Compute takeoffs and landings...")
+    result = compute_takeoff_and_landing.delay()
+    counter = result.get()
+    print("New/recalculated takeoffs/landings: %s" % counter)
+
+
 @manager.command
 def show(airport_name, latitude, longitude, altitude):
     """Show a logbook for <airport_name> located at given position."""
diff --git a/ogn/gateway/__init__.py b/ogn/gateway/__init__.py
index 2a12b37..5a6e4ec 100644
--- a/ogn/gateway/__init__.py
+++ b/ogn/gateway/__init__.py
@@ -58,10 +58,10 @@ class ognGateway:
         try:
             beacon = parse_aprs(line)
         except AprsParseError:
-            logger.error('AprsParseError', exc_info=True)
+            logger.error('AprsParseError while parsing line: %s' % line, exc_info=True)
             return
         except OgnParseError:
-            logger.error('OgnParseError', exc_info=True)
+            logger.error('OgnParseError while parsing line: ' % line, exc_info=True)
             return
 
         if beacon is not None:
diff --git a/ogn/gateway/settings.py b/ogn/gateway/settings.py
index d311da2..0273c48 100644
--- a/ogn/gateway/settings.py
+++ b/ogn/gateway/settings.py
@@ -1,7 +1,7 @@
 APRS_SERVER_HOST = 'aprs.glidernet.org'
-APRS_SERVER_PORT = 14580
+APRS_SERVER_PORT = 10152
 APRS_APP_NAME = 'ogn-gateway-python'
 APRS_APP_VER = '0.2'
 
-APRS_FILTER = 'r/50.0000/10.0000/5000'
+APRS_FILTER = ''
 APRS_KEEPALIVE_TIME = 240