internal static void Departing(this FlightContext context)
{
/*
* First check plausible scenarios. The easiest to track is an aerotow.
*
* If not, wait until the launch is completed.
*/
if (context.Flight.LaunchMethod == LaunchMethods.None)
{
var departure = context.Flight.PositionUpdates
.Where(q => q.Heading != 0 && !double.IsNaN(q.Heading))
.OrderBy(q => q.TimeStamp)
.Take(5)
.ToList();
if (departure.Count > 4)
{
context.Flight.DepartureHeading = Convert.ToInt16(departure.Average(q => q.Heading));
if (context.Flight.DepartureHeading == 0)
{
context.Flight.DepartureHeading = 360;
}
// Only start method recognition after the heading has been determined
context.Flight.LaunchMethod = LaunchMethods.Unknown | LaunchMethods.Aerotow | LaunchMethods.Winch | LaunchMethods.Self;
}
else
{
return;
}
}
if (context.Flight.DepartureTime != null &&
(context.CurrentPosition.TimeStamp - (context.Flight.PositionUpdates.FirstOrDefault(q => q.Speed > 30)?.TimeStamp ?? context.CurrentPosition.TimeStamp)).TotalSeconds < 10)
{
return;
}
// We can safely try to extract the correct path
if (context.Flight.LaunchMethod.HasFlag(LaunchMethods.Unknown | LaunchMethods.Aerotow))
{
var encounters = context.TowEncounter().ToList();
if (encounters.Count(q => q?.Type == EncounterType.Tug || q?.Type == EncounterType.Tow) > 1)
{
return;
}
var encounter = encounters.SingleOrDefault(q => q?.Type == EncounterType.Tug || q?.Type == EncounterType.Tow);
if (encounter != null)
{
context.Flight.LaunchMethod = LaunchMethods.Aerotow
| (encounter.Type == EncounterType.Tug
? LaunchMethods.OnTow
: LaunchMethods.TowPlane
);
context.Flight.Encounters.Add(encounter);
context.StateMachine.Fire(FlightContext.Trigger.TrackAerotow);
return;
}
else if (encounters.Any(q => q == null))
{
return;
}
context.Flight.LaunchMethod &= ~LaunchMethods.Aerotow;
}
if (context.Flight.LaunchMethod.HasFlag(LaunchMethods.Unknown))
{
var x = new DenseVector(context.Flight.PositionUpdates.Select(w => (w.TimeStamp - context.Flight.DepartureTime.Value).TotalSeconds).ToArray());
var y = new DenseVector(context.Flight.PositionUpdates.Select(w => w.Altitude).ToArray());
var interpolation = CubicSpline.InterpolateNatural(x, y);
var r = new List <double>();
var r2 = new List <double>();
for (var i = 0; i < (context.CurrentPosition.TimeStamp - context.Flight.DepartureTime.Value).TotalSeconds; i++)
{
r.Add(interpolation.Differentiate(i));
r2.Add(interpolation.Differentiate2(i));
}
// When the initial climb has completed
if (interpolation.Differentiate((context.CurrentPosition.TimeStamp - context.Flight.DepartureTime.Value).TotalSeconds) < 0)
{
// Skip the first element because heading is 0 when in rest
var averageHeading = context.Flight.PositionUpdates.Skip(1).Average(q => q.Heading);
// ToDo: Add check to see whether there is another aircraft nearby
if (context.Flight.PositionUpdates
.Skip(1)
.Where(q => interpolation.Differentiate((context.CurrentPosition.TimeStamp - context.Flight.DepartureTime.Value).TotalSeconds) > 0)
.Select(q => Geo.GetHeadingError(averageHeading, q.Heading))
.Any(q => q > 20) ||
Geo.DistanceTo(
context.Flight.PositionUpdates.First().Location,
context.CurrentPosition.Location) > 3000)
{
context.Flight.LaunchMethod = LaunchMethods.Self;
}
else
{
context.Flight.LaunchMethod = LaunchMethods.Winch;
}
context.Flight.LaunchFinished = context.CurrentPosition.TimeStamp;
context.InvokeOnLaunchCompletedEvent();
context.StateMachine.Fire(FlightContext.Trigger.LaunchCompleted);
}
}
}
internal static void Stationary(this FlightContext context)
{
if (context.CurrentPosition == null)
{
return;
}
if (context.CurrentPosition.Speed > 30)
{
double groundElevation = 0;
if (context.Options.NearbyRunwayAccessor != null)
{
groundElevation = context.Options.NearbyRunwayAccessor(
context.CurrentPosition.Location,
Constants.RunwayQueryRadius)?
.OrderBy(q => q.Sides
.Min(w => Geo.DistanceTo(w, context.CurrentPosition.Location))
).FirstOrDefault()
?.Sides
.Average(q => q.Z)
?? 0;
}
// Walk back to when the speed was 0
var start = context.Flight.PositionUpdates
.Where(q => (q.Speed == 0 || double.IsNaN(q.Speed)) &&
(context.CurrentPosition.TimeStamp - q.TimeStamp).TotalSeconds < 30)
.OrderByDescending(q => q.TimeStamp)
.FirstOrDefault();
if (start == null && context.CurrentPosition.Altitude > (groundElevation + Constants.ArrivalHeight))
{
// The flight was already in progress, or we could not find the starting point (trees in line of sight?)
// Create an estimation about the departure time. Unless contact happens high in the sky
context.Flight.DepartureInfoFound = false;
context.InvokeOnRadarContactEvent();
context.StateMachine.Fire(FlightContext.Trigger.TrackMovements);
return;
}
else if (start == null && context.CurrentPosition.Altitude <= (groundElevation + Constants.ArrivalHeight))
{
// ToDo: Try to estimate the departure time
context.Flight.DepartureTime = context.CurrentPosition.TimeStamp;
context.Flight.DepartureLocation = context.CurrentPosition.Location;
context.Flight.PositionUpdates
.Where(q => q.TimeStamp < context.Flight.DepartureTime.Value)
.ToList()
.ForEach(q => context.Flight.PositionUpdates.Remove(q));
context.Flight.DepartureInfoFound = false;
}
else if (start != null)
{
context.Flight.DepartureTime = start.TimeStamp;
context.Flight.DepartureLocation = context.CurrentPosition.Location;
// Remove points not related to this flight
context.Flight.PositionUpdates
.Where(q => q.TimeStamp < context.Flight.DepartureTime.Value)
.ToList()
.ForEach(q => context.Flight.PositionUpdates.Remove(q));
context.Flight.DepartureInfoFound = false;
}
context.Flight.DepartureHeading = (short)context.CurrentPosition.Heading;
context.InvokeOnTakeoffEvent();
context.StateMachine.Fire(FlightContext.Trigger.Depart);
}
}
internal static void Arriving(this FlightContext context)
{
/*
* - Create an estimate for the arrival time
* - When data shows a landing, use that data
* - When no data is received anymore, use the estimation
*/
double groundElevation = 0;
if (context.Options.NearbyRunwayAccessor != null)
{
groundElevation = context.Options.NearbyRunwayAccessor(
context.CurrentPosition.Location,
Constants.RunwayQueryRadius)?
.OrderBy(q => q.Sides
.Min(w => Geo.DistanceTo(w, context.CurrentPosition.Location))
).FirstOrDefault()
?.Sides
.Average(q => q.Z)
?? 0;
}
if (context.CurrentPosition.Altitude > (groundElevation + Constants.ArrivalHeight))
{
context.Flight.ArrivalTime = null;
context.Flight.ArrivalInfoFound = null;
context.Flight.ArrivalHeading = 0;
context.StateMachine.Fire(FlightContext.Trigger.LandingAborted);
return;
}
var arrival = context.Flight.PositionUpdates
.Where(q => q.Heading != 0 && !double.IsNaN(q.Heading))
.OrderByDescending(q => q.TimeStamp)
.Take(5)
.ToList();
if (!arrival.Any())
{
return;
}
if (context.CurrentPosition.Speed == 0)
{
/*
* If a flight has been in progress, end the flight.
*
* When the aircraft has been registered mid flight the departure
* location is unknown, and so is the time. Therefore look at the
* flag which is set to indicate whether the departure location has
* been found.
*
* ToDo: Also check the vertical speed as it might be an indication
* that the flight is still in progress! (Aerobatic stuff and so)
*/
context.Flight.ArrivalTime = context.CurrentPosition.TimeStamp;
context.Flight.ArrivalInfoFound = true;
context.Flight.ArrivalHeading = Convert.ToInt16(arrival.Average(q => q.Heading));
context.Flight.ArrivalLocation = arrival.First().Location;
if (context.Flight.ArrivalHeading == 0)
{
context.Flight.ArrivalHeading = 360;
}
context.InvokeOnLandingEvent();
context.StateMachine.Fire(FlightContext.Trigger.Arrived);
}
else if (!(context.Flight.ArrivalInfoFound ?? true) &&
context.CurrentPosition.TimeStamp > context.Flight.ArrivalTime.Value.AddSeconds(Constants.ArrivalTimeout))
{
// Our theory needs to be finalized
context.InvokeOnLandingEvent();
context.StateMachine.Fire(FlightContext.Trigger.Arrived);
}
else
{
var previousPoint = context.Flight.PositionUpdates.LastOrDefault();
if (previousPoint == null)
{
return;
}
// Take the average climbrate over the last few points
var climbrates = new List <double>();
var speeds = new List <double>();
for (var i = context.Flight.PositionUpdates.Count - 1; i > Math.Max(context.Flight.PositionUpdates.Count - 15, 0); i--)
{
var p1 = context.Flight.PositionUpdates[i];
var p2 = context.Flight.PositionUpdates[i - 1];
var deltaAltitude = p1.Altitude - p2.Altitude;
var deltaTime = p1.TimeStamp - p2.TimeStamp;
speeds.Add(p1.Speed);
climbrates.Add(deltaAltitude / deltaTime.TotalSeconds);
}
if (!climbrates.Any())
{
context.Flight.ArrivalTime = null;
context.Flight.ArrivalInfoFound = null;
context.Flight.ArrivalHeading = 0;
context.Flight.ArrivalLocation = null;
return;
}
var average = climbrates.Average();
double ETUA = context.CurrentPosition.Altitude / -average;
if (double.IsInfinity(ETUA) || ETUA > (60 * 10) || ETUA < 0)
{
context.Flight.ArrivalTime = null;
context.Flight.ArrivalInfoFound = null;
context.Flight.ArrivalHeading = 0;
context.Flight.ArrivalLocation = null;
return;
}
var averageHeading = arrival.Average(q => q.Heading);
context.Flight.ArrivalTime = context.CurrentPosition.TimeStamp.AddSeconds(ETUA);
context.Flight.ArrivalInfoFound = false;
context.Flight.ArrivalHeading = Convert.ToInt16(averageHeading);
context.Flight.ArrivalLocation = context.CurrentPosition.Location.HaversineExtrapolation(
averageHeading,
speeds.Average() * 0.514444444 * ETUA); // Knots to m/s times the estimated time until arrival
}
}