/**
* After take-off has been detected, we check if the ground speed goes
* below a certain threshold that indicates the aircraft has ceased
* flying. To avoid false positives while wave/ridge soaring, this
* threshold is half of the given take-off speed.
*/
gcc_pure
static bool
CheckLandingSpeed(fixed takeoff_speed, const NMEAInfo &basic)
{
return !CheckTakeOffSpeed(Half(takeoff_speed), basic);
}
void
FlyingComputer::Compute(fixed takeoff_speed,
const NMEAInfo &basic,
const DerivedInfo &calculated,
FlyingState &flying)
{
if (!basic.time_available || !basic.location_available)
return;
const fixed dt = delta_time.Update(basic.time, fixed(0.5), fixed(20));
if (negative(dt)) {
Reset();
flying.Reset();
}
if (!positive(dt))
return;
const auto any_altitude = basic.GetAnyAltitude();
if (!basic.airspeed_available && !calculated.altitude_agl_valid &&
any_altitude.first && !negative(last_ground_altitude) &&
any_altitude.second > last_ground_altitude + fixed(250)) {
/* lower the threshold for "not moving" when the aircraft is high
above the take-off airfield and there's no airspeed probe; this
shall reduce the risk of false landing detection when flying in
strong head wind (e.g. ridge or wave) */
fixed dh = any_altitude.second - last_ground_altitude;
if (dh > fixed(1000))
takeoff_speed /= 4;
else if (dh > fixed(500))
takeoff_speed /= 2;
else
takeoff_speed = takeoff_speed * 2 / 3;
}
if (CheckTakeOffSpeed(takeoff_speed, basic) ||
CheckAltitudeAGL(calculated))
Moving(flying, basic.time, dt, basic.location);
else if (!flying.flying ||
(CheckLandingSpeed(takeoff_speed, basic) &&
(!any_altitude.first || !CheckClimbing(dt, any_altitude.second))))
Stationary(flying, basic.time, dt, basic.location);
if (basic.engine_noise_level_available)
CheckPowered(dt, basic, flying);
if (any_altitude.first) {
if (flying.on_ground)
last_ground_altitude = any_altitude.second;
CheckRelease(flying, basic.time, basic.location, any_altitude.second);
} else
sinking_since = fixed(-1);
if (flying.flying && flying.release_location.IsValid()) {
fixed distance = basic.location.Distance(flying.release_location);
if (distance > flying.far_distance) {
flying.far_location = basic.location;
flying.far_distance = distance;
}
}
}
/**
* After take-off has been detected, we check if the ground speed goes
* below a certain threshold that indicates the aircraft has ceased
* flying. To avoid false positives while wave/ridge soaring, this
* threshold is half of the given take-off speed.
*/
gcc_pure
static bool
CheckLandingSpeed(double takeoff_speed, const NMEAInfo &basic)
{
return !CheckTakeOffSpeed(takeoff_speed / 2, basic);
}