Add (slow) [radius, theta, phi] calculation

ogn/commands/dbutils.py

@@ -1,8 +1,13 @@
 import os
 import importlib
-from sqlalchemy import create_engine
+
+from sqlalchemy import create_engine, and_, desc
+from sqlalchemy.sql import null
 from sqlalchemy.orm import sessionmaker
 
+from ogn.model import AircraftBeacon, ReceiverBeacon
+from ogn.utils import wgs84_to_sphere
+
 
 os.environ.setdefault('OGN_CONFIG_MODULE', 'config.default')
 
@@ -11,3 +16,26 @@ engine = create_engine(config.SQLALCHEMY_DATABASE_URI, echo=False)
 
 Session = sessionmaker(bind=engine)
 session = Session()
+
+
+def update_receiver_childs(name):
+    last_receiver_beacon = session.query(ReceiverBeacon) \
+        .filter(ReceiverBeacon.name == name) \
+        .order_by(desc(ReceiverBeacon.timestamp)) \
+        .first()
+
+    if (last_receiver_beacon is None):
+        return
+
+    aircraft_beacons_query = session.query(AircraftBeacon) \
+        .filter(and_(AircraftBeacon.timestamp > last_receiver_beacon.timestamp,
+                     AircraftBeacon.receiver_name == name,
+                     AircraftBeacon.radius == null()))
+
+    for aircraft_beacon in aircraft_beacons_query.all():
+        [radius, theta, phi] = wgs84_to_sphere(last_receiver_beacon,
+                                               aircraft_beacon)
+        aircraft_beacon.radius = radius
+        aircraft_beacon.theta = theta
+        aircraft_beacon.phi = phi
+    session.commit()

ogn/gateway/manage.py

@@ -1,9 +1,11 @@
 import logging
 
 from ogn.gateway.client import ognGateway
-from ogn.commands.dbutils import session
+from ogn.commands.dbutils import session, update_receiver_childs
+from ogn.model import ReceiverBeacon
 
 from manager import Manager
+
 manager = Manager()
 
 logging_formatstr = '%(asctime)s - %(levelname).4s - %(name)s - %(message)s'
@@ -33,6 +35,8 @@ def run(aprs_user='anon-dev', logfile='main.log', loglevel='INFO'):
     gateway.connect()
 
     def process_beacon(beacon):
+        if isinstance(beacon, ReceiverBeacon):
+            update_receiver_childs(beacon.name)
         session.add(beacon)
         session.commit()
 

ogn/utils.py

@@ -60,3 +60,24 @@ def get_country_code(latitude, longitude):
     except KeyError:
         country_code = None
     return country_code
+
+
+def wgs84_to_sphere(receiver_beacon, aircraft_beacon):
+    from math import pi, asin, sqrt, sin, cos, atan2
+    deg2rad = pi / 180
+    rad2deg = 180 / pi
+
+    lat1 = receiver_beacon.latitude * deg2rad
+    lon1 = receiver_beacon.longitude * deg2rad
+    alt1 = receiver_beacon.altitude
+
+    lat2 = aircraft_beacon.latitude * deg2rad
+    lon2 = aircraft_beacon.longitude * deg2rad
+    alt2 = aircraft_beacon.altitude
+
+    distance = 6366000 * 2 * asin(sqrt((sin((lat1 - lat2) / 2))**2 + cos(lat1) * cos(lat2) * (sin((lon1 - lon2) / 2))**2))
+    theta = atan2(alt2 - alt1, distance) * rad2deg
+    phi = atan2(sin(lon1 - lon2) * cos(lat2), cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(lon1 - lon2)) * rad2deg
+
+    radius = sqrt(distance**2 + (alt2 - alt1)**2)
+    return radius, theta, phi

tests/test_utils.py

@@ -1,7 +1,7 @@
 import unittest
 
-from ogn.utils import get_ddb, get_trackable, get_country_code
+from ogn.utils import get_ddb, get_trackable, get_country_code, wgs84_to_sphere
-from ogn.model import AddressOrigin
+from ogn.model import AddressOrigin, Beacon
 
 
 class TestStringMethods(unittest.TestCase):
@@ -43,3 +43,52 @@ class TestStringMethods(unittest.TestCase):
         longitude = -0.0009119
         country_code = get_country_code(latitude, longitude)
         self.assertEqual(country_code, None)
+
+    def test_wgs84_to_sphere(self):
+        receiver_beacon = Beacon()
+        receiver_beacon.latitude = 0
+        receiver_beacon.longitude = 0
+        receiver_beacon.altitude = 0
+
+        # delta: one latitude degree
+        aircraft_beacon = Beacon()
+        aircraft_beacon.latitude = -1
+        aircraft_beacon.longitude = 0
+        aircraft_beacon.altitude = 0
+        [radius, theta, phi] = wgs84_to_sphere(receiver_beacon, aircraft_beacon)
+        self.assertAlmostEqual(radius, 60 * 1852, -2)
+        self.assertEqual(theta, 0)
+        self.assertEqual(phi, 180)
+
+        # delta: one longitude degree at the equator
+        aircraft_beacon.latitude = 0
+        aircraft_beacon.longitude = -1
+        aircraft_beacon.altitude = 0
+        [radius, theta, phi] = wgs84_to_sphere(receiver_beacon, aircraft_beacon)
+        self.assertAlmostEqual(radius, 60 * 1852, -2)
+        self.assertEqual(theta, 0)
+        self.assertEqual(phi, 90)
+
+        # delta: 1000m altitude
+        aircraft_beacon.latitude = 0
+        aircraft_beacon.longitude = 0
+        aircraft_beacon.altitude = 1000
+        [radius, theta, phi] = wgs84_to_sphere(receiver_beacon, aircraft_beacon)
+        self.assertAlmostEqual(radius, 1000, 3)
+        self.assertEqual(theta, 90)
+        self.assertEqual(phi, 0)
+
+        # receiver
+        receiver_beacon.latitude = 48.865
+        receiver_beacon.longitude = 9.2225
+        receiver_beacon.altitude = 574
+
+        # aircraft beacon
+        aircraft_beacon.latitude = 48.74435
+        aircraft_beacon.longitude = 9.578
+        aircraft_beacon.altitude = 929
+
+        [radius, theta, phi] = wgs84_to_sphere(receiver_beacon, aircraft_beacon)
+        self.assertAlmostEqual(radius, 29265.6035812215, -1)
+        self.assertAlmostEqual(theta, 0.694979846308314, 5)
+        self.assertAlmostEqual(phi, -117.1275408121, 5)