/// <summary>
/// Returns the maximum elevation angle Epsilon of all objects on an elevation path are seen from an observer(h1)
/// If the maxixum elevation angle is higher than an object with maxelv could reach the path is cut to this length
/// </summary>
/// <param name="h1">The height of the observer [m].</param>
/// <param name="elv">The array with elevation data [m].</param>
/// <param name="dist">The full path distance [km].</param>
/// <param name="stepwidth">The stepwidth in [m].</param>
/// <param name="freq">The frequency in [GHz].</param>
/// <param name="f1_clearance">The Fresenl Zone F1 clearance [].</param>
/// <param name="maxelv">The maximal elevation an object could have [m].</param>
/// <param name="re">The equivalent earth radius [km].</param>
/// <returns>The HorizonPoint with distance, epsmax and elevation.</returns>
public static HorizonPoint EpsilonMaxFromPath(double h1, ref short[] elv, double dist, double stepwidth, double freq, double f1_clearance, double maxelv, double re)
{
HorizonPoint hp = new HorizonPoint();
stepwidth = stepwidth / 1000.0;
double d = 0;
for (int i = 0; i < elv.Length; i++)
{
double f1 = ScoutBase.Core.Propagation.F1Radius(freq, d, dist - d);
double h2 = elv[i] + f1 * f1_clearance;
double eps = ScoutBase.Core.Propagation.EpsilonFromHeights(h1, d, h2, re);
if (eps > hp.Epsmin)
{
// ignore first 100m
if (d > 0.1)
{
hp.Epsmin = eps;
hp.Dist = d;
hp.Elv = elv[i];
}
}
if (maxelv > 0)
{
double epsmax = ScoutBase.Core.Propagation.EpsilonFromHeights(h1, d, maxelv, re);
if (epsmax < hp.Epsmin)
{
Array.Resize <short>(ref elv, i);
return(hp);
}
}
d += stepwidth;
}
return(hp);
}
public PropagationHorizonDesignator()
{
Lat = 0;
Lon = 0;
h = 0;
Dist = 0;
StepWidth = 0;
QRG = 0;
F1_Clearance = 0;
Radius = 0;
Horizon = new HorizonPoint[360];
for (int i = 0; i < Horizon.Length; i++)
{
Horizon[i] = new HorizonPoint(0, 0, 0);
}
LastUpdated = DateTime.MinValue.ToUniversalTime();
}
public PropagationHorizonDesignator(double lat, double lon, double h, double dist, double qrg, double radius, double f1_clearance, double stepwidth, HorizonPoint[] horizon, DateTime lastupdated, LocalObstructionDesignator localobstruction)
{
Lat = lat;
Lon = lon;
this.h = h;
Dist = dist;
StepWidth = stepwidth;
QRG = qrg;
F1_Clearance = f1_clearance;
Radius = radius;
if (horizon == null)
{
// initialize new horizon array if null
Horizon = new HorizonPoint[360];
for (int i = 0; i < Horizon.Length; i++)
{
Horizon[i] = new HorizonPoint(0, 0, 0);
}
}
else
{
Horizon = horizon;
}
LocalObstruction = localobstruction;
LastUpdated = lastupdated;
if (Horizon == null)
{
return;
}
if (LocalObstruction == null)
{
return;
}
for (int i = 0; i > 360; i++)
{
if ((Horizon[i] != null) && (Horizon[i].Epsmin < LocalObstruction.GetObstruction(h, i)))
{
LocalObstructed = true;
}
}
}
public PropagationHorizonDesignator PropagationHorizonCreate(BackgroundWorker caller, double lat, double lon, double h, double dist, double qrg, double radius, double f1_clearance, double stepwidth, ELEVATIONMODEL model, LocalObstructionDesignator localobstruction, bool savetodatabase = true)
{
// calculate propagation horizon
// report status messages and single data points if called from background thread
HorizonPoint[] hor = new HorizonPoint[360];
bool valid = true;
PropagationHorizonDesignator hd = new PropagationHorizonDesignator(lat, lon, h, dist, qrg, radius, f1_clearance, stepwidth, hor, localobstruction);
for (int j = 0; j < 360; j++)
{
// report progress if called from background worker
if (caller != null)
{
if (caller.WorkerReportsProgress)
{
caller.ReportProgress(-1, "Calculating horizon " + j.ToString() + "° of 360°");
}
}
double eps_min = double.MinValue;
double eps_dist = 0;
short eps_elv = 0;
// find or create elevation path
ElevationPathDesignator ep = ElevationData.Database.ElevationPathFindOrCreateFromBearing(caller, lat, lon, j, dist, stepwidth, model, false);
for (int i = 0; i < ep.Count; i++)
{
double d = i * stepwidth / 1000.0;
double nf = NearFieldSuppression / 1000.0;
double eps;
if (d > nf)
{
double f1c = ScoutBase.Core.Propagation.F1Radius(qrg, d, dist) * f1_clearance;
eps = ScoutBase.Core.Propagation.EpsilonFromHeights(h, d, ep.Path[i] + f1c, radius);
}
else
{
double f1c = ScoutBase.Core.Propagation.F1Radius(qrg, nf, dist) * f1_clearance;
eps = ScoutBase.Core.Propagation.EpsilonFromHeights(h, nf, ep.Path[i] + f1c, radius);
}
if (eps > eps_min)
{
eps_min = eps;
eps_dist = d;
eps_elv = ep.Path[i];
}
}
hor[j] = new HorizonPoint(eps_dist, eps_min, eps_elv);
// report current horizon if called from background worker
if (caller != null)
{
if (caller.WorkerReportsProgress)
{
caller.ReportProgress(j, hor[j]);
}
}
// take status from elevation path
if (!ep.Valid)
{
valid = false;
}
// abort calculation if called from background worker and cancellation pending
if (caller != null)
{
if (caller.WorkerSupportsCancellation && caller.CancellationPending)
{
return(null);
}
}
}
// copy over the horizon and status
hd.Horizon = hor;
hd.Valid = valid;
// store in database if valid
if ((hd != null) && hd.Valid && savetodatabase)
{
this.PropagationHorizonInsertOrUpdateIfNewer(hd, model);
}
return(hd);
}
