Detailed Description

Simple model of the ionosphere ("Klobuchar"), specified in the GPS IS. It is used to compute the satellite signal ionospheric delay seen at the receiver by a single-band user.

See ICD-GPS-200, section 20.3.3.5.2.5 and Figure 20-4.

Verbatim from the above section: "It is estimated that the use of this model will provide at least a 50% reduction in the single-frequency user's RMS error due to ionospheric propagation effects. During extended operations, or for the Block IIR SVs in the Autonav mode if the CS is unable to upload the SVs, the use of this model will yield unpredictable results."

Definition at line 70 of file IonoModel.hpp.

#include <IonoModel.hpp>

Public Member Functions
virtual void	dump (std::ostream &s=std::cout) const

double	getCorrection (const CommonTime &time, const Position &rxgeo, double svel, double svaz, CarrierBand band=CarrierBand::L1) const

bool	getModel (double a[4], double b[4]) const noexcept

	IonoModel () noexcept
	Default constructor, creates an invalid model for lack of parameters. More...

	IonoModel (const double a[4], const double b[4], const bool semicircle_units=true) noexcept

	IonoModel (const EngAlmanac &engalm) noexcept

bool	isValid () const noexcept

	NEW_EXCEPTION_CLASS (InvalidIonoModel, gnsstk::Exception)

bool	operator!= (const IonoModel &right) const noexcept
	Inequality operator. More...

bool	operator== (const IonoModel &right) const noexcept
	Equality operator. More...

void	setModel (const double a[4], const double b[4], const bool semicircle_units=true) noexcept

virtual	~IonoModel () noexcept
	Destructor. More...

Private Attributes
double	alpha [4]

double	beta [4]

bool	valid

Constructor & Destructor Documentation

◆ IonoModel() [1/3]

gnsstk::IonoModel::IonoModel ( )

inlinenoexcept

Default constructor, creates an invalid model for lack of parameters.

Definition at line 80 of file IonoModel.hpp.

◆ ~IonoModel()

virtual gnsstk::IonoModel::~IonoModel ( )

inlinevirtualnoexcept

Destructor.

Definition at line 83 of file IonoModel.hpp.

◆ IonoModel() [2/3]

gnsstk::IonoModel::IonoModel	(	const double	a[4],
		const double	b[4],
		const bool	semicircle_units = `true`
	)

noexcept

Ionosphere model constructor. Creates a valid model with satellite transmitted alpha and beta (Klobuchar) parameters provided by the user.

Parameters

[in]	a	An array containing the four alpha terms.
[in]	b	An array containing the four beta terms.
[in]	semicircle_units	A boolean indicating params are in semicircles (T, default) or radians (F). Note that the IS-GPS-200 defines the algorithm and parameters in terms of semi-circles, not radians; but that the GNSSTk for historical reasons extracts parameters from a GPS Nav message in power of inverse radians. Hence the need for the boolean flag.

Definition at line 52 of file IonoModel.cpp.

◆ IonoModel() [3/3]

gnsstk::IonoModel::IonoModel ( const EngAlmanac & engalm )

noexcept

EngAlmanac constructor. Creates a valid model from and EngAlmanac object.

Parameters

[in] engalm An EngAlmanac object.

Definition at line 59 of file IonoModel.cpp.

Member Function Documentation

◆ dump()

void gnsstk::IonoModel::dump ( std::ostream & s = std::cout ) const

virtual

Dump to contents of the model in human-readable form.

Parameters

[in,out] s Stream to receive the output; defaults to cout

Definition at line 209 of file IonoModel.cpp.

◆ getCorrection()

double gnsstk::IonoModel::getCorrection	(	const CommonTime &	time,
		const Position &	rxgeo,
		double	svel,
		double	svaz,
		CarrierBand	band = `CarrierBand::L1`
	)		const

Get the ionospheric correction value.

Parameters

[in]	time	Time of the observation.
[in]	rxgeo	WGS84 geodetic position of the receiver.
[in]	svel	Elevation angle between the rx and SV (degrees).
[in]	svaz	Azimuth angle between the rx and SV (degrees).
[in]	band	GPS frequency band the observation was made from.

Returns: The ionospheric correction (meters).

Exceptions

InvalidIonoModel

Definition at line 96 of file IonoModel.cpp.

◆ getModel()

bool gnsstk::IonoModel::getModel	(	double	a[4],
		double	b[4]
	)		const

noexcept

Get the raw model contents in semicircle units.

Parameters

[in,out]	a	Ionospheric model alpha parameters
[in,out]	b	Ionospheric model beta parameters

Returns: true if a and b were populated successfully

Definition at line 194 of file IonoModel.cpp.

◆ isValid()

bool gnsstk::IonoModel::isValid ( ) const

inlinenoexcept

Return whether the model contains valid data.

Returns: model validity

Definition at line 118 of file IonoModel.hpp.

◆ operator!=()

bool gnsstk::IonoModel::operator!= ( const IonoModel & right ) const

noexcept

Inequality operator.

Definition at line 188 of file IonoModel.cpp.

◆ operator==()

bool gnsstk::IonoModel::operator== ( const IonoModel & right ) const

noexcept

Equality operator.

Definition at line 177 of file IonoModel.cpp.

◆ setModel()

void gnsstk::IonoModel::setModel	(	const double	a[4],
		const double	b[4],
		const bool	semicircle_units = `true`
	)

noexcept

Method to feed the model with satellite-transmitted alpha and beta parameters from the passed almanac. See the IS-GPS-200, 20.3.3.3.3.2.

Parameters

[in]	a	An array containing the four alpha terms.
[in]	b	An array containing the four beta terms.

Definition at line 73 of file IonoModel.cpp.

Member Data Documentation

◆ alpha

double gnsstk::IonoModel::alpha[4]

private

Definition at line 156 of file IonoModel.hpp.

◆ beta

double gnsstk::IonoModel::beta[4]

private

Definition at line 157 of file IonoModel.hpp.

◆ valid

bool gnsstk::IonoModel::valid

private

Definition at line 159 of file IonoModel.hpp.

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

Detailed Description

Public Member Functions

Private Attributes

Constructor & Destructor Documentation

◆ IonoModel() [1/3]

◆ ~IonoModel()

◆ IonoModel() [2/3]

◆ IonoModel() [3/3]

Member Function Documentation

◆ dump()

◆ getCorrection()

◆ getModel()

◆ isValid()

◆ operator!=()

◆ operator==()

◆ setModel()

Member Data Documentation

◆ alpha

◆ beta

◆ valid