//Retrieve wind data at vessel location
public wx_wind getWind(double vlat, double vlng, double vheight)
{
double epoch_time = Util.getLocalTime(); //Get local time (i.e. UT time)
Dictionary <string, int> idx = get_dim_idx(vlat, vlng, vheight); //Get index of coordinates closest to vessel location
int t = idx["t"]; int z = idx["z"]; int x = idx["x"]; int y = idx["y"];
double uu; double vv; double ww;
ww = interp_var3d(0, t, z, y, x, epoch_time, vheight, vlat, vlng); //Get vertical wind component (w) at vessel location
uu = interp_var3d(1, t, z, y, x, epoch_time, vheight, vlat, vlng); //Get zonal wind component (u) at vessel location
vv = interp_var3d(2, t, z, y, x, epoch_time, vheight, vlat, vlng); //Get meridional wind component (v) at vessel location
//Return data as struct
wx_wind wind_data = new wx_wind();
wind_data.uwind = uu;
wind_data.vwind = vv;
wind_data.zwind = ww;
return(wind_data);
}
public wx_vel getVehicleVel(Vessel vessel, double vlat, double vlng, double vheight, bool wxenabled)
{
Vector3 windVector = Vector3.zero; //Wind in map space
if (wxenabled)
{
//Get wind vector (in meteorological coordinates)
wx_wind windvec = getWind(vlat, vlng, vheight);
windVector.x = (float)windvec.vwind; //North
windVector.y = (float)windvec.zwind; //Up
windVector.z = (float)windvec.uwind; //East
}
//Retrieve mach
double vel_mach;
if (Util.far_GetMachNumber != null)
{
vel_mach = Util.far_GetMachNumber(vessel.mainBody, vessel.altitude, vessel.srf_velocity);
}
else
{
vel_mach = vessel.mach;
}
//Compute indicated airspeed
double vel_ias = Math.Sqrt(((vessel.staticPressurekPa * 1000 * 2) * (Util.RayleighPitotTubeStagPressure(vel_mach) - 1)) / 1.225);
//Get density ratio
double d_ratio;
if (Util.far_GetCurrentDensity != null)
{
d_ratio = Util.far_GetCurrentDensity(vessel.mainBody, vessel.altitude) * invKerbinSLDensity;
}
else
{
d_ratio = vessel.atmDensity / 1.225;
}
//Compute equivalent air speed
double easCoeff = Math.Sqrt(d_ratio);
double vel_eas = vessel.srfSpeed * easCoeff;
if (vessel.staticPressurekPa <= 0)
{
vel_eas = 0;
}
//Get vessel orientation
Vector3d CoM = vessel.CoMD;
Vector3d orbitalVelocity = vessel.obt_velocity;
Vector3d orbitalPosition = CoM - vessel.mainBody.position;
Vector3d up = orbitalPosition.normalized;
Vector3d north = vessel.north;
Vector3d east = vessel.east;
//Compute vessel surface velocity
Vector3d surfaceVelocity = orbitalVelocity - vessel.mainBody.getRFrmVel(CoM);
//Get components of vessel velocity
double speedVertical = Vector3d.Dot(surfaceVelocity, up);
double speedNorth = Vector3d.Dot(vessel.srf_velocity, north);
double speedEast = Vector3d.Dot(vessel.srf_velocity, east);
//Compute vessel ground speed
double vel_grnd = Math.Sqrt(Math.Pow(speedEast, 2) + Math.Pow(speedNorth, 2));
//Get true air speed w.r.t surface
double vel_tas_sfc = Math.Sqrt(Math.Pow((windVector.z - speedEast), 2) + Math.Pow((windVector.x - speedNorth), 2));
//Get true air speed (including vertical component)
double vel_tas = Math.Sqrt(Math.Pow((windVector.z - speedEast), 2) + Math.Pow((windVector.x - speedNorth), 2) + Math.Pow((windVector.y - speedVertical), 2));
//Get component of wind perpendicular and parallel to the vessel's flight path.
double projvu_sc = ((windVector.z * speedEast + windVector.x * speedNorth + windVector.y * speedVertical) / (Math.Pow(speedEast, 2) + Math.Pow(speedNorth, 2) + Math.Pow(speedVertical, 2)));
double vel_par = Math.Sqrt(Math.Pow(projvu_sc * speedEast, 2) + Math.Pow(projvu_sc * speedNorth, 2) + Math.Pow(projvu_sc * speedVertical, 2));
double vel_prp = Math.Sqrt(Math.Pow(windVector.z - projvu_sc * speedEast, 2) + Math.Pow(windVector.x - projvu_sc * speedNorth, 2) + Math.Pow(windVector.y - projvu_sc * speedVertical, 2));
//If ground speed is slower than horizontal component of true air speed then there is a headwind.
if (vel_grnd < vel_tas_sfc)
{
vel_par = vel_par * -1;
}
//Return all fields as struct
wx_vel wx_data = new wx_vel();
wx_data.vel_ias = vel_ias; //Indiciated airspeed
wx_data.vel_tas = vel_tas; //True airspeed
wx_data.vel_eas = vel_eas; //Equivalent airspeed
wx_data.vel_grnd = vel_grnd; //Surface velocity (i.e. ground speed)
wx_data.vel_par = vel_par; //Component of wind perpendicular to aircraft
wx_data.vel_prp = vel_prp; //Component of wind parallel to aircraft
return(wx_data);
}
