Models the 1976 U.S. More...

#include <FGStandardAtmosphere.h>

Inheritance diagram for FGStandardAtmosphere:

Collaboration diagram for FGStandardAtmosphere:

Public Member Functions
	FGStandardAtmosphere (FGFDMExec *)
	Constructor.

virtual	~FGStandardAtmosphere ()
	Destructor.

bool	InitModel (void)

virtual void	PrintStandardAtmosphereTable ()
	Prints the U.S. Standard Atmosphere table.

Temperature access functions.
There are several ways to get the temperature, and several modeled temperature values that can be retrieved. The U.S. Standard Atmosphere temperature either at a specified altitude, or at sea level can be retrieved. These two temperatures do NOT include the effects of any bias or delta gradient that may have been supplied by the user. The modeled temperature and the modeled temperature at sea level can also be retrieved. These two temperatures DO include the effects of an optionally user-supplied bias or delta gradient.
virtual double	GetTemperature (double altitude) const
	Returns the actual modeled temperature in degrees Rankine at a specified altitude. More...

virtual double	GetStdTemperature (double altitude) const
	Returns the standard temperature in degrees Rankine at a specified altitude. More...

virtual double	GetStdTemperatureSL () const
	Returns the standard sea level temperature in degrees Rankine. More...

virtual double	GetStdTemperatureRatio (double h) const
	Returns the ratio of the standard temperature at the supplied altitude over the standard sea level temperature. More...

virtual double	GetTemperatureBias (eTemperature to) const
	Returns the temperature bias over the sea level value in degrees Rankine.

virtual double	GetTemperatureDeltaGradient (eTemperature to)
	Returns the temperature gradient to be applied on top of the standard temperature gradient. More...

virtual void	SetTemperatureSL (double t, eTemperature unit=eFahrenheit)
	Sets the Sea Level temperature, if it is to be different than the standard. More...

virtual void	SetTemperature (double t, double h, eTemperature unit=eFahrenheit)
	Sets the temperature at the supplied altitude, if it is to be different than the standard temperature. More...

virtual void	SetTemperatureBias (eTemperature unit, double t)
	Sets the temperature bias to be added to the standard temperature at all altitudes. More...

virtual void	SetSLTemperatureGradedDelta (eTemperature unit, double t)
	Sets a Sea Level temperature delta that is ramped out by 86 km. More...

virtual void	SetTemperatureGradedDelta (double t, double h, eTemperature unit=eFahrenheit)
	Sets the temperature delta value at the supplied altitude/elevation above sea level, to be added to the standard temperature and ramped out by 86 km. More...

virtual void	ResetSLTemperature ()
	This function resets the model to apply no bias or delta gradient to the temperature. More...

Pressure access functions.
virtual double	GetPressure (double altitude) const
	Returns the pressure at a specified altitude in psf.

virtual double	GetStdPressure100K (double altitude) const
	Returns the standard pressure at a specified altitude in psf.

virtual double	GetStdPressure (double altitude) const
	Returns the standard pressure at the specified altitude.

virtual void	SetPressureSL (ePressure unit, double pressure)
	Sets the sea level pressure for modeling an off-standard pressure profile. More...

virtual void	ResetSLPressure ()
	Resets the sea level to the Standard sea level pressure, and recalculates dependent parameters so that the pressure calculations are standard. More...

Density access functions.
virtual double	GetStdDensity (double altitude) const
	Returns the standard density at a specified altitude.

Public Member Functions inherited from FGAtmosphere
	FGAtmosphere (FGFDMExec *)
	Constructor.

virtual	~FGAtmosphere ()
	Destructor.

virtual double	GetDensityAltitude () const

virtual double	GetPressureAltitude () const

bool	Run (bool Holding)
	Runs the atmosphere forces model; called by the Executive. More...

virtual double	GetTemperature () const
	Returns the actual, modeled temperature at the current altitude in degrees Rankine. More...

virtual double	GetTemperatureSL () const
	Returns the actual, modeled sea level temperature in degrees Rankine. More...

virtual double	GetTemperatureRatio () const
	Returns the ratio of the at-current-altitude temperature as modeled over the sea level value. More...

virtual double	GetTemperatureRatio (double h) const
	Returns the ratio of the temperature as modeled at the supplied altitude over the sea level value. More...

virtual double	GetPressure (void) const
	Returns the pressure in psf.

virtual double	GetPressureSL (ePressure to=ePSF) const

virtual double	GetPressureRatio (void) const
	Returns the ratio of at-altitude pressure over the sea level value.

virtual double	GetDensity (void) const
	Returns the density in slugs/ft^3. More...

virtual double	GetDensity (double altitude) const
	Returns the density in slugs/ft^3 at a given altitude in ft. More...

virtual double	GetDensitySL (void) const
	Returns the sea level density in slugs/ft^3.

virtual double	GetDensityRatio (void) const
	Returns the ratio of at-altitude density over the sea level value.

virtual double	GetSoundSpeed (void) const
	Returns the speed of sound in ft/sec.

virtual double	GetSoundSpeed (double altitude) const
	Returns the speed of sound in ft/sec at a given altitude in ft.

virtual double	GetSoundSpeedSL (void) const
	Returns the sea level speed of sound in ft/sec.

virtual double	GetSoundSpeedRatio (void) const
	Returns the ratio of at-altitude sound speed over the sea level value.

virtual double	GetAbsoluteViscosity (void) const
	Returns the absolute viscosity.

virtual double	GetKinematicViscosity (void) const
	Returns the kinematic viscosity.

Public Member Functions inherited from FGModel
	FGModel (FGFDMExec *)
	Constructor.

virtual	~FGModel ()
	Destructor.

virtual SGPath	FindFullPathName (const SGPath &path) const

FGFDMExec *	GetExec (void)

unsigned int	GetRate (void)
	Get the output rate for the model in frames.

void	SetPropertyManager (FGPropertyManager *fgpm)

void	SetRate (unsigned int tt)
	Set the ouput rate for the model in frames.

Public Member Functions inherited from FGModelFunctions
std::string	GetFunctionStrings (const std::string &delimeter) const
	Gets the strings for the current set of functions. More...

std::string	GetFunctionValues (const std::string &delimeter) const
	Gets the function values. More...

FGFunction *	GetPreFunction (const std::string &name)
	Get one of the "pre" function. More...

bool	Load (Element el, FGPropertyManager PropertyManager, std::string prefix="")

void	PostLoad (Element el, FGPropertyManager PropertyManager, std::string prefix="")

void	PreLoad (Element el, FGPropertyManager PropertyManager, std::string prefix="")

void	RunPostFunctions (void)

void	RunPreFunctions (void)

Public Member Functions inherited from FGJSBBase
	FGJSBBase ()
	Constructor for FGJSBBase.

virtual	~FGJSBBase ()
	Destructor for FGJSBBase.

void	disableHighLighting (void)
	Disables highlighting in the console output.

std::string	GetVersion (void)
	Returns the version number of JSBSim. More...

void	PutMessage (const Message &msg)
	Places a Message structure on the Message queue. More...

void	PutMessage (const std::string &text)
	Creates a message with the given text and places it on the queue. More...

void	PutMessage (const std::string &text, bool bVal)
	Creates a message with the given text and boolean value and places it on the queue. More...

void	PutMessage (const std::string &text, int iVal)
	Creates a message with the given text and integer value and places it on the queue. More...

void	PutMessage (const std::string &text, double dVal)
	Creates a message with the given text and double value and places it on the queue. More...

int	SomeMessages (void)
	Reads the message on the queue (but does not delete it). More...

void	ProcessMessage (void)
	Reads the message on the queue and removes it from the queue. More...

Message *	ProcessNextMessage (void)
	Reads the next message on the queue and removes it from the queue. More...

Protected Member Functions
virtual void	bind (void)

void	CalculateLapseRates ()
	Recalculate the lapse rate vectors when the temperature profile is altered in a way that would change the lapse rates, such as when a gradient is applied. More...

void	CalculatePressureBreakpoints ()
	Calculate (or recalculate) the atmospheric pressure breakpoints at the altitudes in the standard temperature table. More...

void	Debug (int from)

Protected Member Functions inherited from FGAtmosphere
void	Calculate (double altitude)
	Calculate the atmosphere for the given altitude.

virtual double	ConvertFromPSF (double t, ePressure unit=ePSF) const

virtual double	ConvertToPSF (double t, ePressure unit=ePSF) const

virtual double	ConvertToRankine (double t, eTemperature unit) const

Protected Member Functions inherited from FGModel
virtual bool	Load (Element *el)
	Loads this model. More...

Protected Member Functions inherited from FGJSBBase
void	Debug (int)

Protected Attributes
double	GradientFadeoutAltitude

std::vector< double >	LapseRateVector

std::vector< double >	PressureBreakpointVector

FGTable *	StdAtmosTemperatureTable

double	StdSLdensity

double	StdSLpressure

double	StdSLsoundspeed

double	StdSLtemperature

double	TemperatureBias

double	TemperatureDeltaGradient

Protected Attributes inherited from FGAtmosphere
const double	Beta

double	Density

double	DensityAltitude

double	KinematicViscosity

double	Pressure

double	PressureAltitude

double	rSLdensity

double	rSLpressure

double	rSLsoundspeed

double	rSLtemperature

double	SLdensity

double	SLpressure

double	SLsoundspeed

double	SLtemperature

double	Soundspeed

const double	SutherlandConstant

double	Temperature

double	Viscosity

Protected Attributes inherited from FGModel
unsigned int	exe_ctr

FGFDMExec *	FDMExec

FGPropertyManager *	PropertyManager

unsigned int	rate

Protected Attributes inherited from FGModelFunctions
FGPropertyReader	LocalProperties

std::vector< FGFunction * >	PostFunctions

std::vector< FGFunction * >	PreFunctions

Additional Inherited Members
Public Types inherited from FGAtmosphere
enum	ePressure { eNoPressUnit =0, ePSF, eMillibars, ePascals, eInchesHg }
	Enums for specifying pressure units.

enum	eTemperature { eNoTempUnit =0, eFahrenheit, eCelsius, eRankine, eKelvin }
	Enums for specifying temperature units.

Public Types inherited from FGJSBBase
enum	{ eL = 1, eM, eN }
	Moments L, M, N.

enum	{ eP = 1, eQ, eR }
	Rates P, Q, R.

enum	{ eU = 1, eV, eW }
	Velocities U, V, W.

enum	{ eX = 1, eY, eZ }
	Positions X, Y, Z.

enum	{ ePhi = 1, eTht, ePsi }
	Euler angles Phi, Theta, Psi.

enum	{ eDrag = 1, eSide, eLift }
	Stability axis forces, Drag, Side force, Lift.

enum	{ eRoll = 1, ePitch, eYaw }
	Local frame orientation Roll, Pitch, Yaw.

enum	{ eNorth = 1, eEast, eDown }
	Local frame position North, East, Down.

enum	{ eLat = 1, eLong, eRad }
	Locations Radius, Latitude, Longitude.

enum	{ inNone = 0, inDegrees, inRadians, inMeters, inFeet }
	Conversion specifiers.

Static Public Member Functions inherited from FGJSBBase
static double	CelsiusToFahrenheit (double celsius)
	Converts from degrees Celsius to degrees Fahrenheit. More...

static double	CelsiusToKelvin (double celsius)
	Converts from degrees Celsius to degrees Kelvin. More...

static double	CelsiusToRankine (double celsius)
	Converts from degrees Celsius to degrees Rankine. More...

static double	Constrain (double min, double value, double max)
	Constrain a value between a minimum and a maximum value.

static bool	EqualToRoundoff (double a, double b)
	Finite precision comparison. More...

static bool	EqualToRoundoff (float a, float b)
	Finite precision comparison. More...

static bool	EqualToRoundoff (float a, double b)
	Finite precision comparison. More...

static bool	EqualToRoundoff (double a, float b)
	Finite precision comparison. More...

static double	FahrenheitToCelsius (double fahrenheit)
	Converts from degrees Fahrenheit to degrees Celsius. More...

static double	FeetToMeters (double measure)
	Converts from feet to meters. More...

static double	GaussianRandomNumber (void)

static double	KelvinToCelsius (double kelvin)
	Converts from degrees Kelvin to degrees Celsius. More...

static double	KelvinToFahrenheit (double kelvin)
	Converts from degrees Kelvin to degrees Fahrenheit. More...

static double	KelvinToRankine (double kelvin)
	Converts from degrees Kelvin to degrees Rankine. More...

static double	MachFromVcalibrated (double vcas, double p, double psl, double rhosl)
	Calculate the Mach number from the calibrated airspeed. More...

static double	PitotTotalPressure (double mach, double p)
	Compute the total pressure in front of the Pitot tube. More...

static double	RankineToCelsius (double rankine)
	Converts from degrees Rankine to degrees Celsius. More...

static double	RankineToKelvin (double rankine)
	Converts from degrees Rankine to degrees Kelvin. More...

static double	sign (double num)

static double	VcalibratedFromMach (double mach, double p, double psl, double rhosl)
	Calculate the calibrated airspeed from the Mach number. More...

Public Attributes inherited from FGAtmosphere
struct JSBSim::FGAtmosphere::Inputs	in

Public Attributes inherited from FGModel
std::string	Name

Static Public Attributes inherited from FGJSBBase
static short	debug_lvl = 1

static char	highint [5] = {27, '[', '1', 'm', '\0' }
	highlights text

static char	halfint [5] = {27, '[', '2', 'm', '\0' }
	low intensity text

static char	normint [6] = {27, '[', '2', '2', 'm', '\0' }
	normal intensity text

static char	reset [5] = {27, '[', '0', 'm', '\0' }
	resets text properties

static char	underon [5] = {27, '[', '4', 'm', '\0' }
	underlines text

static char	underoff [6] = {27, '[', '2', '4', 'm', '\0' }
	underline off

static char	fgblue [6] = {27, '[', '3', '4', 'm', '\0' }
	blue text

static char	fgcyan [6] = {27, '[', '3', '6', 'm', '\0' }
	cyan text

static char	fgred [6] = {27, '[', '3', '1', 'm', '\0' }
	red text

static char	fggreen [6] = {27, '[', '3', '2', 'm', '\0' }
	green text

static char	fgdef [6] = {27, '[', '3', '9', 'm', '\0' }
	default text

Static Protected Member Functions inherited from FGJSBBase
static std::string	CreateIndexedPropertyName (const std::string &Property, int index)

Static Protected Attributes inherited from FGJSBBase
static const double	degtorad = 0.017453292519943295769236907684886

static const double	fpstokts = 1.0/ktstofps

static const double	fttom = 0.3048

static int	gaussian_random_number_phase = 0

static const double	hptoftlbssec = 550.0

static const double	in3tom3 = 1.638706E-5

static const double	inchtoft = 0.08333333

static const double	inhgtopa = 3386.38

static const std::string	JSBSim_version = "1.0 " __DATE__ " " __TIME__

static const double	kgtolb = 2.20462

static const double	kgtoslug = 0.06852168

static const double	ktstofps = 1.68781

static const double	lbtoslug = 1.0/slugtolb

static Message	localMsg

static const double	m3toft3 = 1.0/(fttomfttomfttom)

static double	Mair = 28.9645

static unsigned int	messageId = 0

static std::queue< Message >	Messages

static const std::string	needed_cfg_version = "2.0"

static const double	psftoinhg = 0.014138

static const double	psftopa = 47.88

static const double	radtodeg = 57.295779513082320876798154814105

static double	Reng = 1716.56

static double	Rstar = 1545.348

static const double	SHRatio = 1.40

static const double	slugtolb = 32.174049

Detailed Description

Models the 1976 U.S.

Standard Atmosphere, with the ability to modify the temperature and pressure. A base feature of the model is the temperature profile that is stored as an FGTable object with this data:

GeoMet Alt    Temp      GeoPot Alt  GeoMet Alt
   (ft)      (deg R)      (km)        (km)
 ---------  --------    ----------  ----------
       0.0    518.67 //    0.000       0.000
   36151.6    390.0  //   11.000      11.019
   65823.5    390.0  //   20.000      20.063
  105518.4    411.6  //   32.000      32.162
  155347.8    487.2  //   47.000      47.350
  168677.8    487.2  //   51.000      51.413
  235570.9    386.4  //   71.000      71.802
  282152.2    336.5; //   84.852      86.000

The pressure is calculated at lower altitudes through the use of two equations that are presented in the U.S. Standard Atmosphere document (see references). Density, kinematic viscosity, speed of sound, etc., are all calculated based on various constants and temperature and pressure. At higher altitudes (above 86 km (282152 ft) a different and more complicated method of calculating pressure is used. The temperature may be modified through the use of several methods. Ultimately, these access methods allow the user to modify the sea level standard temperature, and/or the sea level standard pressure, so that the entire profile will be consistently and accurately calculated.

Properties

atmosphere/delta-T
atmosphere/T-sl-dev-F

Author: Jon Berndt

See also: "U.S. Standard Atmosphere, 1976", NASA TM-X-74335

Version

Id: FGStandardAtmosphere.h,v 1.17 2012/04/13 13:18:27 jberndt Exp

Definition at line 103 of file FGStandardAtmosphere.h.

Member Function Documentation

◆ CalculateLapseRates()

void CalculateLapseRates ( )

protected

Recalculate the lapse rate vectors when the temperature profile is altered in a way that would change the lapse rates, such as when a gradient is applied.

This function is also called to initialize the lapse rate vector.

Definition at line 377 of file FGStandardAtmosphere.cpp.

 {
   for (unsigned int bh=0; bh<LapseRateVector.size(); bh++)
   {
     double t0 = (*StdAtmosTemperatureTable)(bh+1,1);
     double t1 = (*StdAtmosTemperatureTable)(bh+2,1);
     double h0 = (*StdAtmosTemperatureTable)(bh+1,0);
     double h1 = (*StdAtmosTemperatureTable)(bh+2,0);
     LapseRateVector[bh] = (t1 - t0) / (h1 - h0) + TemperatureDeltaGradient;
   }
 }

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◆ CalculatePressureBreakpoints()

void CalculatePressureBreakpoints ( )

protected

Calculate (or recalculate) the atmospheric pressure breakpoints at the altitudes in the standard temperature table.

Definition at line 391 of file FGStandardAtmosphere.cpp.

 {
   for (unsigned int b=0; b<PressureBreakpointVector.size()-1; b++) {
     double BaseTemp = (*StdAtmosTemperatureTable)(b+1,1);
     double BaseAlt = (*StdAtmosTemperatureTable)(b+1,0);
     double UpperAlt = (*StdAtmosTemperatureTable)(b+2,0);
     double deltaH = UpperAlt - BaseAlt;
     double Tmb = BaseTemp
                  + TemperatureBias 
                  + (GradientFadeoutAltitude - BaseAlt)*TemperatureDeltaGradient;
     if (LapseRateVector[b] != 0.00) {
       double Lmb = LapseRateVector[b];
       double Exp = Mair/(Rstar*Lmb);
       double factor = Tmb/(Tmb + Lmb*deltaH);
       PressureBreakpointVector[b+1] = PressureBreakpointVector[b]*pow(factor, Exp);
     } else {
       PressureBreakpointVector[b+1] = PressureBreakpointVector[b]*exp(-Mair*deltaH/(Rstar*Tmb));
     }
   }
 }

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◆ GetStdTemperature()

double GetStdTemperature ( double altitude ) const

virtual

Returns the standard temperature in degrees Rankine at a specified altitude.

Parameters

altitude The altitude in feet above sea level (ASL) to get the temperature at.

Returns: The STANDARD temperature in degrees Rankine at the specified altitude.

Definition at line 213 of file FGStandardAtmosphere.cpp.

 {
   double Lk9 = 0.00658368; // deg R per foot
   double Tinf = 1800.0; // Same as 1000 Kelvin
   double temp = Tinf;
 
   if (altitude < 298556.4) {                // 91 km - station 8
 
     double GeoPotAlt = (altitude*20855531.5)/(20855531.5+altitude);
     temp = StdAtmosTemperatureTable->GetValue(GeoPotAlt);
 
   } else if (altitude < 360892.4) {        // 110 km - station 9
 
     temp = 473.7429 - 137.38176 * sqrt(1.0 - pow((altitude - 298556.4)/65429.462, 2.0));
 
   } else if (altitude < 393700.8) {        // 120 km - station 10
 
     temp = 432 + Lk9 * (altitude - 360892.4);
 
   } else if (altitude < 3280839.9) {        // 1000 km station 12
 
     double lambda = 0.00001870364;
     double eps = (altitude - 393700.8) * (20855531.5 + 393700.8) / (20855531.5 + altitude);
     temp = Tinf - (Tinf - 648.0) * exp(-lambda*eps);
 
   }
 
   return temp;
 }

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◆ GetStdTemperatureRatio()

virtual double GetStdTemperatureRatio ( double h ) const

inlinevirtual

Returns the ratio of the standard temperature at the supplied altitude over the standard sea level temperature.

Definition at line 139 of file FGStandardAtmosphere.h.

139 { return GetStdTemperature(h)*rSLtemperature; }

JSBSim::FGStandardAtmosphere::GetStdTemperature

virtual double GetStdTemperature(double altitude) const

Returns the standard temperature in degrees Rankine at a specified altitude.

Definition: FGStandardAtmosphere.cpp:213

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◆ GetStdTemperatureSL()

virtual double GetStdTemperatureSL ( ) const

inlinevirtual

Returns the standard sea level temperature in degrees Rankine.

Returns: The STANDARD temperature at sea level in degrees Rankine.

Definition at line 135 of file FGStandardAtmosphere.h.

135 { return GetStdTemperature(0.0); }

JSBSim::FGStandardAtmosphere::GetStdTemperature

virtual double GetStdTemperature(double altitude) const

Returns the standard temperature in degrees Rankine at a specified altitude.

Definition: FGStandardAtmosphere.cpp:213

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◆ GetTemperature()

double GetTemperature ( double altitude ) const

virtual

Returns the actual modeled temperature in degrees Rankine at a specified altitude.

Parameters

altitude The altitude above sea level (ASL) in feet.

Returns: Modeled temperature in degrees Rankine at the specified altitude.

Implements FGAtmosphere.

Definition at line 199 of file FGStandardAtmosphere.cpp.

 {
   double GeoPotAlt = (altitude*20855531.5)/(20855531.5+altitude);
 
   double T = StdAtmosTemperatureTable->GetValue(GeoPotAlt) + TemperatureBias;
   if (altitude <= GradientFadeoutAltitude)
     T += TemperatureDeltaGradient * (GradientFadeoutAltitude - altitude);
 
   return T;
 }

◆ GetTemperatureDeltaGradient()

virtual double GetTemperatureDeltaGradient ( eTemperature to )

inlinevirtual

Returns the temperature gradient to be applied on top of the standard temperature gradient.

Definition at line 147 of file FGStandardAtmosphere.h.

148 { if (to == eCelsius || to == eKelvin) return TemperatureDeltaGradient/1.80; else return TemperatureDeltaGradient; }

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◆ ResetSLPressure()

void ResetSLPressure ( )

virtual

Resets the sea level to the Standard sea level pressure, and recalculates dependent parameters so that the pressure calculations are standard.

Definition at line 423 of file FGStandardAtmosphere.cpp.

 {
   PressureBreakpointVector[0] = StdSLpressure; // psf
   CalculatePressureBreakpoints();
 }

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◆ ResetSLTemperature()

void ResetSLTemperature ( )

virtual

This function resets the model to apply no bias or delta gradient to the temperature.

The delta gradient and bias values are reset to 0.0, and the standard temperature is used for the entire temperature profile at all altitudes.

Definition at line 414 of file FGStandardAtmosphere.cpp.

 {
   TemperatureBias = TemperatureDeltaGradient = 0.0;
   CalculateLapseRates();
   CalculatePressureBreakpoints();
 }

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◆ SetPressureSL()

void SetPressureSL	(	ePressure	unit,
		double	pressure
	)

virtual

Sets the sea level pressure for modeling an off-standard pressure profile.

This could be useful in the case where the pressure at an airfield is known or set for a particular simulation run.

Parameters

pressure	The pressure in the units specified.
unit	the unit of measure that the specified pressure is supplied in.

Reimplemented from FGAtmosphere.

Definition at line 187 of file FGStandardAtmosphere.cpp.

 {
   double press = ConvertToPSF(pressure, unit);
 
   PressureBreakpointVector[0] = press;
   CalculatePressureBreakpoints();
 }

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◆ SetSLTemperatureGradedDelta()

void SetSLTemperatureGradedDelta	(	eTemperature	unit,
		double	t
	)

virtual

Sets a Sea Level temperature delta that is ramped out by 86 km.

The value of the delta is used to calculate a delta gradient that is applied to the temperature at all altitudes below 86 km (282152 ft). For instance, if a temperature of 20 degrees F is supplied, the delta gradient would be 20/282152 - or, about 7.09E-5 degrees/ft. At sea level, the full 20 degrees would be added to the standard temperature, but that 20 degree delta would be reduced by 7.09E-5 degrees for every foot of altitude above sea level, so that by 86 km, there would be no further delta added to the standard temperature. The graded delta can be used along with the a bias to tailor the temperature profile as desired.

Parameters

t	the sea level temperature delta value in the unit provided.
unit	the unit of the temperature.

Definition at line 329 of file FGStandardAtmosphere.cpp.

 {
   SetTemperatureGradedDelta(deltemp, 0.0, unit);
 }

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◆ SetTemperature()

void SetTemperature	(	double	t,
		double	h,
		eTemperature	unit = `eFahrenheit`
	)

virtual

Sets the temperature at the supplied altitude, if it is to be different than the standard temperature.

This function will calculate a bias - a difference - from the standard atmosphere temperature at the supplied altitude and will apply that calculated bias to the entire temperature profile. If a graded delta is present, that will be included in the calculation - that is, regardless of any graded delta present, a temperature bias will be determined so that the temperature requested in this function call will be reached.

Parameters

t	The temperature value in the unit provided.
h	The altitude in feet above sea level.
unit	The unit of the temperature.

Implements FGAtmosphere.

Definition at line 295 of file FGStandardAtmosphere.cpp.

 {
   double targetSLtemp = ConvertToRankine(t, unit);
 
   TemperatureBias = 0.0;
   TemperatureBias = targetSLtemp - GetTemperature(h);
   CalculatePressureBreakpoints();
 }

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◆ SetTemperatureBias()

void SetTemperatureBias	(	eTemperature	unit,
		double	t
	)

virtual

Sets the temperature bias to be added to the standard temperature at all altitudes.

This function sets the bias - the difference - from the standard atmosphere temperature. This bias applies to the entire temperature profile. Another way to set the temperature bias is to use the SetSLTemperature function, which replaces the value calculated by this function with a calculated bias.

Parameters

t	the temperature value in the unit provided.
unit	the unit of the temperature.

Definition at line 306 of file FGStandardAtmosphere.cpp.

 {
   if (unit == eCelsius || unit == eKelvin)
     t *= 1.80; // If temp delta "t" is given in metric, scale up to English
 
   TemperatureBias = t;
   CalculatePressureBreakpoints();
 }

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◆ SetTemperatureGradedDelta()

void SetTemperatureGradedDelta	(	double	t,
		double	h,
		eTemperature	unit = `eFahrenheit`
	)

virtual

Sets the temperature delta value at the supplied altitude/elevation above sea level, to be added to the standard temperature and ramped out by 86 km.

This function computes the sea level delta from the standard atmosphere temperature at sea level.

Parameters

t	the temperature skew value in the unit provided.
unit	the unit of the temperature.

Definition at line 341 of file FGStandardAtmosphere.cpp.

 {
   if (unit == eCelsius || unit == eKelvin)
     deltemp *= 1.80; // If temp delta "t" is given in metric, scale up to English
 
   TemperatureDeltaGradient = deltemp/(GradientFadeoutAltitude - h);
   CalculateLapseRates();
   CalculatePressureBreakpoints();
 }

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◆ SetTemperatureSL()

void SetTemperatureSL	(	double	t,
		eTemperature	unit = `eFahrenheit`
	)

virtual

Sets the Sea Level temperature, if it is to be different than the standard.

This function will calculate a bias - a difference - from the standard atmosphere temperature and will apply that bias to the entire temperature profile. This is one way to set the temperature bias. Using the SetTemperatureBias function will replace the value calculated by this function.

Parameters

t	the temperature value in the unit provided.
unit	the unit of the temperature.

Reimplemented from FGAtmosphere.

Definition at line 321 of file FGStandardAtmosphere.cpp.

 {
   SetTemperature(t, 0.0, unit);
 }

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The documentation for this class was generated from the following files:

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Properties

Member Function Documentation

◆ CalculateLapseRates()

◆ CalculatePressureBreakpoints()

◆ GetStdTemperature()

◆ GetStdTemperatureRatio()

◆ GetStdTemperatureSL()

◆ GetTemperature()

◆ GetTemperatureDeltaGradient()

◆ ResetSLPressure()

◆ ResetSLTemperature()

◆ SetPressureSL()

◆ SetSLTemperatureGradedDelta()

◆ SetTemperature()

◆ SetTemperatureBias()

◆ SetTemperatureGradedDelta()

◆ SetTemperatureSL()