Errors concerning GNSS observations. More...

Classes
struct	ModelParametersCosineType
	Model parameters for the 'cosine - type' model. More...

struct	ModelParametersExponential
	Model parameters for the 'exponential' model. More...

struct	ModelParametersRtklib
	Model parameters for the 'RTKLIB' model. More...

struct	ModelParametersSine
	Model parameters for the 'sine' model. More...

struct	ModelParametersSineCN0
	Model parameters for the 'sine + CN0' model. More...

struct	ModelParametersSineOffset
	Model parameters for the 'sine + offset' model. More...

struct	ModelParametersSineSqrt
	Model parameters for the 'sine - sqrt' model. More...

Public Types
enum	Model : uint8_t { None , SINE , SINE_OFFSET , SINE_CN0 , RTKLIB , SINE_SQRT , EXPONENTIAL , COSINE_TYPE , COUNT }
	Models. More...

Public Member Functions
double	carrierMeasErrorVar (const SatelliteSystem &satSys, double elevation, double cn0) const
	Calculates the measurement Error Variance for carrier-phase observations.

double	codeBiasErrorVar () const
	Returns the Code Bias Error Variance.

	GnssMeasurementErrorModel ()
	Default constructor.

double	psrMeasErrorVar (const SatelliteSystem &satSys, double elevation, double cn0) const
	Calculates the measurement Error Variance for pseudorange observations.

double	psrRateMeasErrorVar (const Frequency &freq, int8_t num, double elevation, double cn0) const
	Returns the Pseudo-range rate Error Variance.

bool	ShowGuiWidgets (const char *id, float width)
	Shows a GUI widgets.

Private Member Functions
void	updateStdDevCurvePlot (Model model)
	Updates the curve plot data for the given model.

double	weightingFunction (Model model, double elevation, double cn0) const
	Calculates the weighting function for the standard deviation.

Static Private Member Functions
static double	satSysErrorFactorVariance (const SatelliteSystem &satSys)
	Returns an error factor for the variance depending on the satellite system.

Private Attributes
double	_carrierStdDev
	Carrier Measurement error standard deviation per Frequency [m].

double	_codeStdDev
	Code/Pseudorange Measurement error standard deviation per Frequency [m].

double	_dopplerStdDev
	Doppler Frequency error factor [Hz] - Measurement error standard deviation.

Model	_model
	Model to use.

ModelParametersCosineType	_modelParametersCosineType
	Model parameters for the 'cosine - type' model.

ModelParametersExponential	_modelParametersExponential
	Model parameters for the 'exponential' model.

ModelParametersRtklib	_modelParametersRtklib
	Model parameters for the 'RTKLIB' model.

ModelParametersSine	_modelParametersSine
	Model parameters for the 'sine' model.

ModelParametersSineCN0	_modelParametersSineCN0
	Model parameters for the 'sine + CN0' model.

ModelParametersSineOffset	_modelParametersSineOffset
	Model parameters for the 'sine + offset' model.

ModelParametersSineSqrt	_modelParametersSineSqrt
	Model parameters for the 'sine - sqrt' model.

double	_plotCN0
	Carrier-to-Noise density [dB-Hz] to use in the plot.

std::vector< std::vector< double > >	_stdDevCurvePlot
	Standard deviations for plotting.

Static Private Attributes
static constexpr std::array< double, PLOT_SAMPLES >	_elevation
	Elevation data for plotting [rad].

static constexpr std::array< double, PLOT_SAMPLES >	_elevation_deg
	Elevation data for plotting [rad].

static constexpr size_t	PLOT_SAMPLES
	Amount of samples for the plot.

Friends
void	from_json (const json &j, GnssMeasurementErrorModel &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersCosineType &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersExponential &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersRtklib &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersSine &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersSineCN0 &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersSineOffset &obj)
	Converts the provided json object into a node object.

void	from_json (const json &j, GnssMeasurementErrorModel::ModelParametersSineSqrt &obj)
	Converts the provided json object into a node object.

void	to_json (json &j, const GnssMeasurementErrorModel &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersCosineType &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersExponential &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersRtklib &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersSine &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersSineCN0 &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersSineOffset &obj)
	Converts the provided object into json.

void	to_json (json &j, const ModelParametersSineSqrt &obj)
	Converts the provided object into json.

Detailed Description

Errors concerning GNSS observations.

Member Enumeration Documentation

◆ Model

enum NAV::GnssMeasurementErrorModel::Model : uint8_t

Models.

Enumerator
None	Measurement error model turned off.
SINE	Sine. See [39] Dach 2015.
SINE_OFFSET	Sine with offset. See [51] Zhang 2021 eq. 7, p. 3.
SINE_CN0	Sine and CN0 dependent. See [17] Groves, ch. 9.4.2.4, eq. 9.168, p. 422 (range acceleration is neglected)
RTKLIB	RTKLIB error model. See [44] RTKLIB ch. E.6, eq. E.6.24, p. 162.
SINE_SQRT	Sine square-root. See [26] Kiliszek 2022, table 2, p. 5.
EXPONENTIAL	Exponential. See [19] Euler and Goad 1991 / [4] Li et al. 2016.
COSINE_TYPE	Cosine Type. See [18] Hadas 2020 eq. 14, p. 8.
COUNT	Amount of items in the enum.

Member Function Documentation

◆ carrierMeasErrorVar()

double NAV::GnssMeasurementErrorModel::carrierMeasErrorVar	(	const SatelliteSystem &	satSys,
		double	elevation,
		double	cn0 ) const

nodiscard

Calculates the measurement Error Variance for carrier-phase observations.

Parameters

[in]	satSys	Satellite System
[in]	elevation	Satellite Elevation in [rad]
[in]	cn0	Carrier-to-Noise density [dB-Hz]

Returns: Variance of the measurement error [m^2]

◆ codeBiasErrorVar()

double NAV::GnssMeasurementErrorModel::codeBiasErrorVar ( ) const

nodiscard

Returns the Code Bias Error Variance.

Returns: Variance of the code bias error [m^2]

◆ psrMeasErrorVar()

double NAV::GnssMeasurementErrorModel::psrMeasErrorVar	(	const SatelliteSystem &	satSys,
		double	elevation,
		double	cn0 ) const

nodiscard

Calculates the measurement Error Variance for pseudorange observations.

Parameters

[in]	satSys	Satellite System
[in]	elevation	Satellite Elevation in [rad]
[in]	cn0	Carrier-to-Noise density [dB-Hz]

Returns: Variance of the measurement error [m^2]

◆ psrRateMeasErrorVar()

double NAV::GnssMeasurementErrorModel::psrRateMeasErrorVar	(	const Frequency &	freq,
		int8_t	num,
		double	elevation,
		double	cn0 ) const

nodiscard

Returns the Pseudo-range rate Error Variance.

Parameters

[in]	freq	Frequency the measurement originates from
[in]	num	Frequency number. Only used for GLONASS G1 and G2
[in]	elevation	Satellite Elevation in [rad]
[in]	cn0	Carrier-to-Noise density [dB-Hz]

Returns: Variance of the Pseudo-range rate error [m^2/s^2]

◆ satSysErrorFactorVariance()

static double NAV::GnssMeasurementErrorModel::satSysErrorFactorVariance ( const SatelliteSystem & satSys )

staticnodiscardprivate

Returns an error factor for the variance depending on the satellite system.

Parameters

satSys Satellite system

◆ ShowGuiWidgets()

bool NAV::GnssMeasurementErrorModel::ShowGuiWidgets	(	const char *	id,
		float	width )

Shows a GUI widgets.

Parameters

[in]	id	Unique id for ImGui.
[in]	width	Width of the widgets

◆ updateStdDevCurvePlot()

void NAV::GnssMeasurementErrorModel::updateStdDevCurvePlot ( Model model )

private

Updates the curve plot data for the given model.

Parameters

model Error model to use

◆ weightingFunction()

double NAV::GnssMeasurementErrorModel::weightingFunction	(	Model	model,
		double	elevation,
		double	cn0 ) const

nodiscardprivate

Calculates the weighting function for the standard deviation.

Parameters

[in]	model	Model to use
[in]	elevation	Satellite Elevation in [rad]
[in]	cn0	Carrier-to-Noise density [dB-Hz]