IonoModel Class Reference
[GPS solution algorithms and Tropospheric]

#include <IonoModel.hpp>

List of all members.

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Detailed Description

Model of the ionosphere.

It is used to compute the delay of the satellite signal as seen at the receiver caused by the ionosphere for a "one frequency" 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 78 of file IonoModel.hpp.

Public Types
enum	Frequency { L1, L2 }
Public Member Functions
	IonoModel () throw ()
	default constructor, creates an invalid model
virtual	~IonoModel () throw ()
	destructor
	IonoModel (const double a[4], const double b[4]) throw ()
	constructor.
	IonoModel (const EngAlmanac &engalm) throw ()
	EngAlmanac constructor.
void	setModel (const double a[4], const double b[4]) throw ()
	Method to feed the model with satellite transmitted alpha and beta parameters provided from almanac.
bool	isValid () const throw ()
	returns the validity of the model.
double	getCorrection (const DayTime &time, const Geodetic &rxgeo, double svel, double svaz, Frequency freq=L1) const throw (InvalidIonoModel)
	get the ionospheric correction value.
bool	operator== (const IonoModel &right) const throw ()
	equality operator
bool	operator!= (const IonoModel &right) const throw ()
	inequality operator

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Member Enumeration Documentation

enum Frequency

Enumeration values: L1  L1 frequency (1575.42 MHz). L2  L2 frequency (1227.60 MHz). Definition at line 93 of file IonoModel.hpp.

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Constructor & Destructor Documentation

IonoModel (   )  throw () [inline]

default constructor, creates an invalid model Definition at line 100 of file IonoModel.hpp.

virtual ~IonoModel (   )  throw () [inline, virtual]

destructor Definition at line 103 of file IonoModel.hpp.

IonoModel (  const double  a[4], const double  b[4] )  throw ()

constructor. Creates a valid model with satellite transmitted alpha and beta parameters provided from almanac. Parameters: a  an array containing the four alpha terms b  an array containing the four beta terms Definition at line 58 of file IonoModel.cpp.

IonoModel (  const EngAlmanac &  engalm  )  throw ()

EngAlmanac constructor. Creates a valid model from and EngAlmanac object Parameters: engalm  an EngAlmanac object Definition at line 63 of file IonoModel.cpp. References gpstk::beta().

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Member Function Documentation

double getCorrection (  const DayTime &  time, const Geodetic &  rxgeo, double  svel, double  svaz, Frequency  freq = L1 )  const throw (InvalidIonoModel)

get the ionospheric correction value. Parameters: time  the time of the observation rxgeo  the WGS84 geodetic position of the receiver svel  the elevation angle between the rx and SV (degrees) svaz  the azimuth angle between the rx and SV (degrees) freq  the GPS frequency the observation was made from Returns: the ionospheric correction (meters) Definition at line 89 of file IonoModel.cpp. References gpstk::beta(), gpstk::cos(), GPSTK_THROW, PI, gpstk::sin(), and gpstk::TWO_PI.

bool isValid (  void   )  const throw () [inline]

returns the validity of the model. Returns: model validity Definition at line 132 of file IonoModel.hpp.

bool operator!= (  const IonoModel &  right  )  const throw ()

inequality operator Definition at line 173 of file IonoModel.cpp. References gpstk::operator==().

bool operator== (  const IonoModel &  right  )  const throw ()

equality operator Definition at line 162 of file IonoModel.cpp. References gpstk::beta().

void setModel (  const double  a[4], const double  b[4] )  throw ()

Method to feed the model with satellite transmitted alpha and beta parameters provided from almanac. Parameters: a  an array containing the four alpha terms b  an array containing the four beta terms Definition at line 78 of file IonoModel.cpp. References gpstk::beta().

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

• IonoModel.hpp
• IonoModel.cpp

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