def update_beacon_receiver_distance(name):
"""
Calculate the distance between the receiver and its received aircrafts
and write this data into each aircraft_beacon.
"""
last_receiver_beacon = app.session.query(ReceiverBeacon) \
.filter(ReceiverBeacon.name == name) \
.order_by(desc(ReceiverBeacon.timestamp)) \
.first()
if (last_receiver_beacon is None):
return
aircraft_beacons_query = app.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():
location0 = (last_receiver_beacon.latitude, last_receiver_beacon.longitude)
location1 = (aircraft_beacon.latitude, aircraft_beacon.longitude)
alt0 = last_receiver_beacon.altitude
alt1 = aircraft_beacon.altitude
(flat_distance, phi) = haversine_distance(location0, location1)
theta = atan2(alt1 - alt0, flat_distance) * 180 / pi
distance = sqrt(flat_distance**2 + (alt1 - alt0)**2)
aircraft_beacon.radius = distance
aircraft_beacon.theta = theta
aircraft_beacon.phi = phi
app.session.commit()
logger.warning("Updated receiver {}.".format(name))
def test_haversine_distance(self):
# delta: one latitude degree
location0 = (0, 0)
location1 = (-1, 0)
(distance, phi) = haversine_distance(location0, location1)
self.assertAlmostEqual(distance, 60 * 1852, -2)
self.assertEqual(phi, 180)
# delta: one longitude degree at the equator
location0 = (0, 0)
location1 = (0, -1)
(distance, phi) = haversine_distance(location0, location1)
self.assertAlmostEqual(distance, 60 * 1852, -2)
self.assertEqual(phi, 90)
# delta: 29000m
location0 = (48.865, 9.2225)
location1 = (48.74435, 9.578)
(distance, phi) = haversine_distance(location0, location1)
self.assertAlmostEqual(distance, 29265.6035812215, -1)
self.assertAlmostEqual(phi, -117.1275408121, 5)
