/// Returns the standard pressure at the specified altitude.
public virtual double GetStdPressure(double altitude)
{
double GeoPotAlt = GeopotentialAltitude(altitude);
// Iterate through the altitudes to find the current Base Altitude
// in the table. That is, if the current altitude (the argument passed in)
// is 20000 ft, then the base altitude from the table is 0.0. If the
// passed-in altitude is 40000 ft, the base altitude is 36089.2388 ft (and
// the index "b" is 2 - the second entry in the table).
double BaseAlt = StdAtmosTemperatureTable.GetElement(1, 0);
int numRows = StdAtmosTemperatureTable.GetNumRows();
int b;
for (b = 0; b < numRows - 2; ++b)
{
double testAlt = StdAtmosTemperatureTable.GetElement(b + 2, 0);
if (GeoPotAlt < testAlt)
{
break;
}
BaseAlt = testAlt;
}
double Tmb = GetStdTemperature(GeometricAltitude(BaseAlt));
double deltaH = GeoPotAlt - BaseAlt;
double Lmb = LapseRates[b];
if (Lmb != 0.0)
{
double Exp = Constants.g0 / (Rdry * Lmb);
double factor = Tmb / (Tmb + Lmb * deltaH);
return(StdPressureBreakpoints[b] * Math.Pow(factor, Exp));
}
else
{
return(StdPressureBreakpoints[b] * Math.Exp(-Constants.g0 * deltaH / (Rdry * Tmb)));
}
}
/// Destructor
//virtual ~FGStandardAtmosphere();
public override bool InitModel()
{
// Assume the altitude to fade out the gradient at is at the highest
// altitude in the table. Above that, other functions are used to
// calculate temperature.
gradientFadeoutAltitude = StdAtmosTemperatureTable.GetElement(StdAtmosTemperatureTable.GetNumRows(), 0);
temperatureDeltaGradient = 0.0;
temperatureBias = 0.0;
LapseRates = StdLapseRates;
PressureBreakpoints = StdPressureBreakpoints;
SLpressure = StdSLpressure;
SLtemperature = StdSLtemperature;
SLdensity = StdSLdensity;
SLsoundspeed = StdSLsoundspeed;
Calculate(0.0);
// PrintStandardAtmosphereTable();
return(true);
}