public void Process(LightningContext context)
{
var closePackets = context.Datapackets.Where(x => x.Received > this.packet.Received - TOACorrelator.MAXDELAY);
var fullInfo = (from data in closePackets
join
status in context.Statuspackets
on data.Batchid equals status.Batchid
select new
{
DetectionInstance = DetectionInstance.FromPacket(data),
Status = status
}).ToList();
foreach (var x in fullInfo)
{
x.DetectionInstance.DetectorLat = x.Status.Gpslat.Value;
x.DetectionInstance.DetectorLon = x.Status.Gpslon.Value;
}
Strike strike = TOACorrelator.Correlate(fullInfo.Select(x => x.DetectionInstance).ToList());
if (strike != null)
{
context.Add(strike);
}
}
public static Strike Correlate(List <DetectionInstance> instances)
{
if (instances.Any())
{
// select the first (not in any order)
var rootDetector = instances.OrderBy(x => x.DetectionTime).First();
List <DetectorDelta> detectorDeltas = new List <DetectorDelta>();
// create the intersections
foreach (var secondaryDetector in instances.Where(x => x != rootDetector))
{
var firstToHear = rootDetector.DetectionTime > secondaryDetector.DetectionTime ? rootDetector : secondaryDetector;
var secondToHear = rootDetector.DetectionTime > secondaryDetector.DetectionTime ? secondaryDetector : rootDetector;
detectorDeltas.Add(new DetectorDelta
{
deltaLat = rootDetector.DetectorLat - secondaryDetector.DetectorLat,
deltaLon = rootDetector.DetectorLon - secondaryDetector.DetectorLon,
deltaTime = rootDetector.DetectionTime - secondaryDetector.DetectionTime,
Primary = firstToHear,
Secondary = secondToHear,
Angle = Math.Atan2(secondToHear.DetectorLat - firstToHear.DetectorLat, secondToHear.DetectorLon - firstToHear.DetectorLon)
});
}
var strike = new Strike();
detectorDeltas = detectorDeltas.OrderBy(x => x.deltaTime).ToList();
foreach (var delta in detectorDeltas)
{
var distance = delta.GetKilometers();
var timeDiff = delta.deltaTime;
// time diff is the radius of the 'circle of difference' and 'opposite of the RHTriangle'
var adjacent = timeDiff * SIGNALSPEED;
var hypotenuse = distance;
var opposite = Math.Sqrt((hypotenuse * hypotenuse) - (adjacent * adjacent));
// sin theta = O / H
var angleFromDetector = Math.Asin(opposite / hypotenuse);
// this angle represents the angle from normal between the two points, relative, get absolute.
var finalAngle = angleFromDetector + delta.Angle;
// as we are treating as a front, no curve, take detector 1 as point for now ( could work out midpoint of line between detectors)
strike.Vectors.Add(new Vector()
{
Angle = finalAngle, Lat = delta.Primary.DetectorLat, Lon = delta.Primary.DetectorLon
});
}
if (strike.Vectors.Any())
{
return(strike);
}
}
return(null);
}
