Fast multipath propagation model. More...

#include <WsfEM_FastMultipath.hpp>

Inheritance diagram for WsfEM_FastMultipath:

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Collaboration diagram for WsfEM_FastMultipath:

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Public Member Functions
	WsfEM_FastMultipath ()
	WsfEM_FastMultipath (const WsfEM_FastMultipath &aSrc)
WsfEM_FastMultipath &	operator= (const WsfEM_FastMultipath &aRhs)=delete
	~WsfEM_FastMultipath () override
WsfEM_Propagation *	Clone () const override
double	ComputePropagationFactor (WsfEM_Interaction &aInteraction, WsfEnvironment &aEnvironment) override
virtual double	ComputeReflectionGain (WsfEM_XmtrRcvr *aXmtrRcvrPtr, const WsfEM_Interaction::BeamData &aBeamData, const WsfEM_Interaction::RelativeData &aRelTgtLoc, double aDepressionAngle, double aFrequency, WsfEM_Types::Polarization aPolarization)
bool	ProcessInput (UtInput &aInput) override
void	SetSoilMoistureFraction (double aSoilMoistureFraction)
void	SetSurfaceRoughness (double aSurfaceRoughness)
Public Member Functions inherited from WsfEM_Propagation
	WsfEM_Propagation ()
	Constructor.
	~WsfEM_Propagation () override=default
const char *	GetScriptClassName () const override
bool	DebugEnabled () const
	Is 'debug' enabled?
virtual bool	Initialize (WsfEM_XmtrRcvr *aXmtrRcvrPtr)
virtual bool	Initialize (WsfEM_Xmtr *aXmtrPtr)
bool	ProcessInput (UtInput &aInput) override
virtual bool	IsNullModel () const
Public Member Functions inherited from WsfObject
	WsfObject ()
	This is the constructor for the WsfObject class.
	~WsfObject () override
	This is the destructor for the WsfObject class.
const char *	GetScriptClassName () const override
const std::string &	GetType () const
WsfStringId	GetTypeId () const
	Get the string ID of the 'type' of the object.
void	SetType (WsfStringId aType)
const std::string &	GetBaseType () const
WsfStringId	GetBaseTypeId () const
const TypeList &	GetTypeList () const
bool	IsA_TypeOf (WsfStringId aType) const
WsfObject &	operator= (const WsfObject &aRhs)
	Assignment operator.
template<typename T>
void	Serialize (T &aBuff)
	For XIO (de)serialization.
const std::string &	GetName () const
WsfStringId	GetNameId () const
void	SetName (WsfStringId aName)

Static Public Member Functions
static WsfEM_Propagation *	ObjectFactory (const std::string &aTypeName)
	Factory method called by WsfEM_PropagationTypes.
static void	ComputeReflectionCoefficient (double aGrazingAngle, const std::complex< double > &aDielectricConstant, WsfEM_Types::Polarization aPolarization, double &aMagnitude, double &aPhaseShift)
static bool	ComputeReflectionGeometry (double aEarthRadius, double aAntHeight, double aTgtSlantRange, double aTgtElevation, double &aAntToRefSlantRange, double &aRefToTgtSlantRange, double &aDepressionAngle, double &aGrazingAngle, double &aPathLengthDifference)
static void	GetSoilDielectricConstant (double aFrequency, double aMoistureFraction, std::complex< double > &aDielectricConstant)

Additional Inherited Members
Public Types inherited from WsfObject
typedef std::vector< WsfStringId >	TypeList
	The list of types returned by GetTypeList.
Protected Member Functions inherited from WsfEM_Propagation
	WsfEM_Propagation (const WsfEM_Propagation &aSrc)
	Copy constructor.
	WsfObject (const WsfObject &aSrc)
	Copy constructor (for Clone()).
Protected Attributes inherited from WsfEM_Propagation
bool	mDebugEnabled

Detailed Description

Fast multipath propagation model.

Constructor & Destructor Documentation

◆ WsfEM_FastMultipath() [1/2]

WsfEM_FastMultipath::WsfEM_FastMultipath ( )

Referenced by Clone(), ObjectFactory(), operator=(), and WsfEM_FastMultipath().

◆ WsfEM_FastMultipath() [2/2]

WsfEM_FastMultipath::WsfEM_FastMultipath ( const WsfEM_FastMultipath & aSrc )

References WsfEM_FastMultipath().

◆ ~WsfEM_FastMultipath()

WsfEM_FastMultipath::~WsfEM_FastMultipath ( )

override

Member Function Documentation

◆ Clone()

WsfEM_Propagation * WsfEM_FastMultipath::Clone ( ) const

overridevirtual

Return a copy of this object. Must be implemented by all derived types. If cloning is impossible, a WsfUncloneableException should be thrown.

Implements WsfEM_Propagation.

References WsfEM_FastMultipath(), and WsfEM_Propagation::WsfEM_Propagation().

◆ ComputePropagationFactor()

double WsfEM_FastMultipath::ComputePropagationFactor	(	WsfEM_Interaction &	aInteraction,
		WsfEnvironment &	aEnvironment )

overridevirtual

Compute the propagation factor for the current interaction.

Parameters

aInteraction	The current interaction.
aEnvironment	The environment (sea state, land formation, land coverage).

Returns: The pattern propagation factor (F40) as a linear value (not dB).

Implements WsfEM_Propagation.

◆ ComputeReflectionCoefficient()

void WsfEM_FastMultipath::ComputeReflectionCoefficient	(	double	aGrazingAngle,
		const std::complex< double > &	aEpsilon,
		WsfEM_Types::Polarization	aPolarization,
		double &	aMagnitude,
		double &	aPhaseShift )

static

Compute the magnitude and phase shift of a reflected signal.

Parameters

aGrazingAngle	[input] The grazing angle (radians)
aEpsilon	[input] The relative dielectric constant of the soil.
aPolarization	[input] The polarization of the signal.
aMagnitude	[output] The magnitude of the complex reflection coefficient.
aPhaseShift	[output] The phase shift (radians) of the complex reflection coefficient.

References WsfEM_Types::cPOL_VERTICAL, and gamma.

Referenced by ComputePropagationFactor(), and operator=().

◆ ComputeReflectionGain()

double WsfEM_FastMultipath::ComputeReflectionGain	(	WsfEM_XmtrRcvr *	aXmtrRcvrPtr,
		const WsfEM_Interaction::BeamData &	aBeamData,
		const WsfEM_Interaction::RelativeData &	aRelTgtLoc,
		double	aDepressionAngle,
		double	aFrequency,
		WsfEM_Types::Polarization	aPolarization )

virtual

Compute the antenna gain in the direction of the reflection point.

Parameters

aXmtrRcvrPtr	Pointer to the transmitter/receiver.
aBeamData	The beam pointing data.
aRelTgtLoc	The position of the target relative to the antenna.
aDepressionAngle	The elevation angle of the reflection point relative to the horizontal plane. This should be negative to represent that it is below the horizontal plane.
aFrequency	The frequency of the signal (Hz)
aPolarization	The polarization of the signal

References WsfEM_Antenna::ComputeBeamAspect(), WsfEM_Antenna::ConvertNED_VectorToWCS(), WsfEM_Antenna::ConvertWCS_VectorToNED(), WsfEM_XmtrRcvr::GetAntenna(), WsfEM_XmtrRcvr::GetAntennaGain(), WsfEM_Interaction::BeamData::mEBS_Az, WsfEM_Interaction::BeamData::mEBS_El, WsfEM_Interaction::RelativeData::mUnitVecWCS, and WsfEM_Interaction::BeamData::mWCS_ToBeamTransform.

Referenced by ComputePropagationFactor(), and operator=().

◆ ComputeReflectionGeometry()

bool WsfEM_FastMultipath::ComputeReflectionGeometry	(	double	aEarthRadius,
		double	aAntHeight,
		double	aTgtSlantRange,
		double	aTgtElevation,
		double &	aAntToRefSlantRange,
		double &	aRefToTgtSlantRange,
		double &	aAntElevationAngle,
		double &	aGrazingAngle,
		double &	aPathLengthDifference )

static

Compute the reflection geometry for a smooth, spherical earth.

This method determines the reflection point using the algorithm defined in chapter 6 of:

"Radar Range-Performance Analysis", Lamont V. Blake, 1986, Artech House, Inc.

Parameters

aEarthRadius	[input] The effective earth radius (a_e in the algorithm)
aAntHeight	[input] Antenna above MSL (meters). (h_1 in the algorithm).
aTgtSlantRange	[input] The slant range from the antenna to the target (R_d in the algorithm).
aTgtElevation	[input] The elevation angle of the target relative to the horizontal plane at the antenna. (theta_d in the algorithm).
aAntToRefSlantRange	[output] The slant range from the antenna to the reflection point. (R_1 in the algorithm).
aRefToTgtSlantRange	[output] The slant range from the reflection point to the target. (R_2 in the algorithm).
aAntElevationAngle	[output] The angle between the horizontal plane at the antenna and the ray from the antenna to the reflection point. This is always negative to indicate that it is BELOW. (theta_r in the algorithm).
aGrazingAngle	[output] The angle between the reflection path and the horizontal at the reflection point. (psi in the algorithm).
aPathLengthDifference	[output] The difference in the path length for the direct and reflected path.

Returns: true if successfully computed or false if either the antenna or target is below the ground.

Referenced by ComputePropagationFactor(), and operator=().

◆ GetSoilDielectricConstant()

void WsfEM_FastMultipath::GetSoilDielectricConstant	(	double	aFrequency,
		double	aMoistureFraction,
		std::complex< double > &	aDielectricConstant )

static

Determines the relative dielectric constant of soil as a function of the radar frequency and the moisture content by volume of the soil.

The tabular data below and the notation used in the subroutine are contained on pages 14 and 15 of 'Radar Propagation at Low Altitudes,' by M. L. Meeks, Artech House, Inc., Dedham, Massachusetts, 1982.

Parameters

aFrequency	[input] Frequency in Hertz.
aMoistureFraction	[input] The moisture content by volume of the soil [0..1].
aDielectricConstant	[output] The complex relative dielectric constant.

Referenced by ComputePropagationFactor(), and operator=().

◆ ObjectFactory()

WsfEM_Propagation * WsfEM_FastMultipath::ObjectFactory ( const std::string & aTypeName )

static

Factory method called by WsfEM_PropagationTypes.

References WsfEM_FastMultipath(), and WsfEM_Propagation::WsfEM_Propagation().

Referenced by operator=(), and WsfEM_PropagationTypes::WsfEM_PropagationTypes().

◆ operator=()

WsfEM_FastMultipath & WsfEM_FastMultipath::operator= ( const WsfEM_FastMultipath & aRhs )

delete

References ComputeReflectionCoefficient(), ComputeReflectionGain(), ComputeReflectionGeometry(), GetSoilDielectricConstant(), ObjectFactory(), SetSoilMoistureFraction(), SetSurfaceRoughness(), WsfEM_FastMultipath(), and WsfEM_Propagation::WsfEM_Propagation().

◆ ProcessInput()

bool WsfEM_FastMultipath::ProcessInput ( UtInput & aInput )

overridevirtual

Process input from a generic source.

Examine the current input command. If it is NOT one of the commands recognized by this class then it simply returns 'false'. If it is one of the commands recognized by this class then it processes the command and returns 'true'.

Parameters

aInput a reference to a UtInput object.

Returns: 'true' if the command was one recognized by the class or 'false' if not.

Exceptions

UtInput::ExceptionBase (or an object derived from it) if the command was recognized but contains some sort of error.

Note: If a derived class does not recognize the command (i.e.: the return value is false) then it should call the base class ProcessInput method. This chain should continue until either the command is recognized or the top-level base class is encountered.

Reimplemented from WsfObject.

References WsfEM_Propagation::ProcessInput(), SetSoilMoistureFraction(), and SetSurfaceRoughness().

◆ SetSoilMoistureFraction()

void WsfEM_FastMultipath::SetSoilMoistureFraction ( double aSoilMoistureFraction )

Referenced by operator=(), and ProcessInput().

◆ SetSurfaceRoughness()

void WsfEM_FastMultipath::SetSurfaceRoughness ( double aSurfaceRoughness )

Referenced by operator=(), and ProcessInput().

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

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ WsfEM_FastMultipath() [1/2]

◆ WsfEM_FastMultipath() [2/2]

◆ ~WsfEM_FastMultipath()

Member Function Documentation

◆ Clone()

◆ ComputePropagationFactor()

◆ ComputeReflectionCoefficient()

◆ ComputeReflectionGain()

◆ ComputeReflectionGeometry()

◆ GetSoilDielectricConstant()

◆ ObjectFactory()

◆ operator=()

◆ ProcessInput()

◆ SetSoilMoistureFraction()

◆ SetSurfaceRoughness()