DensityAltitude.h

/***************************************************************************
 *   Copyright (C) 2019-2022 by Stefan Kebekus                             *
 *   stefan.kebekus@gmail.com                                              *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
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 *   (at your option) any later version.                                   *
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 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
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 *   GNU General Public License for more details.                          *
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 ***************************************************************************/
 
#pragma once
 
#include "units/Density.h"
#include "units/Distance.h"
#include "units/Pressure.h"
#include "units/Temperature.h"
 
namespace Weather {

class DensityAltitude {
public:
    //
    // Methods
    //

    static Units::Distance calculateDensityAltitudeDryAirApproximation(Units::Temperature oat, Units::Pressure qnh, Units::Distance geometricAltitude);
 
    
    static Units::Distance calculateDensityAltitude(Units::Temperature oat, Units::Pressure qnh, Units::Distance geometricAltitude, Units::Temperature dewPoint);
private:
    // calculates the actual density altitude either with or without a given dewpoint
    static Units::Distance calculateDensityAltitudeInternal(Units::Temperature oat, Units::Pressure qnh, Units::Distance geometricAltitude, Units::Temperature dewPoint, bool bWithDewPoint);
 
    // calculates the vapour pressure using the Herman Wobus approximation polynominal curve
    static Units::Pressure calculateVapourPressure(Units::Temperature dewPoint);
 
    // calculates the air density
    static Units::Pressure calculateAbsolutePressure(Units::Pressure qnh, Units::Distance height);
 
    // calculates the air density either with or without a given dewpoint
    static Units::Density calculateAirDensity(Units::Temperature temperature, Units::Pressure qnh, Units::Distance height, Units::Temperature dewPoint, bool bWithDewPoint);
 
 
    // converts the geometricAltitude into geopotential altitude
    static Units::Distance geometricAltitudeToGeopotentialAltitude(Units::Distance geometricAltitude);
};
 
} // namespace Weather