Detailed Description

Class containing data elements unique to GLONASS Civil C-Nav ephemerides.

See also: PNBGLOCNavDataFactory for additional details on the long-term dynamic model parameters.

Definition at line 57 of file GLOCNavEph.hpp.

#include <GLOCNavEph.hpp>

Inheritance diagram for gnsstk::GLOCNavEph:

[legend]

Public Member Functions
NavDataPtr	clone () const override
	Create a deep copy of this object. More...

void	dump (std::ostream &s, DumpDetail dl) const override

void	dumpTerse (std::ostream &s) const

void	fixFit ()

CommonTime	getUserTime () const override

bool	getXvt (const CommonTime &when, Xvt &xvt, const ObsID &=ObsID()) override

	GLOCNavEph ()
	Sets the nav message type and all other data members to 0. More...

bool	haveLTDMP () const

bool	validate () const override

Public Member Functions inherited from gnsstk::GLOCNavData
	GLOCNavData ()
	Sets the nav message type and all other data members to 0. More...

Public Member Functions inherited from gnsstk::OrbitData
std::list< std::string >	compare (const NavDataPtr &right) const override

bool	isSameData (const NavDataPtr &right) const override

Public Member Functions inherited from gnsstk::NavData
virtual std::string	getClassName () const

std::string	getDumpTime (DumpDetail dl, const CommonTime &t) const

std::string	getDumpTimeHdr (DumpDetail dl) const

virtual CommonTime	getNearTime () const

std::string	getSignalString () const

bool	getSVN (const SatID &sat, const gnsstk::CommonTime &when, std::string &svn) const

	NavData ()
	Initialize internal data fields. More...

Static Public Member Functions
static double	factorToSigma (int8_t factor)

Static Public Member Functions inherited from gnsstk::NavData
static gnsstk::SatMetaDataStore *	getSatMetaDataStore ()
	Accessor for python. More...

static void	setSatMetaDataStore (gnsstk::SatMetaDataStore *smds)
	Accessor for python. More...

Public Attributes
Triple	acc
	Satellite acceleration at tb in km/s**2. More...

Triple	apcOffset
	L3OC APC offset from center of mass. More...

double	clkBias
	Satellite clock bias in sec (tau^j). More...

double	driftRate
	Half rate of relative deviation of carrier freq. More...

uint8_t	EjE
	Age of ephemeris (6-hour intervals). More...

uint8_t	EjT
	Age of clock (6-hour intervals). More...

int8_t	FjE
	Accuracy factors dependent on ephemeris errors. More...

int8_t	FjT
	Accuracy factors dependent on clock errors. More...

double	freqBias
	Satellite relative frequency bias (gamma^j). More...

GLOCNavHeader	header11
	Header (incl xmit time) data from string 11. More...

GLOCNavHeader	header12
	Header (incl xmit time) data from string 12. More...

GLOCNavLTDMP	ltdmp
	Long-term dynamic model parameters. More...

GLOCSatType	Mj
	What satellite j is and what it transmits. More...

uint8_t	N4
	Number of leap years since 1996. More...

uint16_t	NT
	Day within four-year interval N4. More...

Triple	pos
	Satellite position at tb in km. More...

uint8_t	PS
	Number of strings from this type 10 to the next. More...

GLOCRegime	RjE
	Regime for generation of ephemeris data. More...

GLOCRegime	RjT
	Regime for generation of clock data. More...

double	step

double	tauc
	Correction for GLONASS to Moscow time. More...

double	taucdot
	Rate of correction for GLONASS to Moscow time. More...

double	tauDelta
	Offset of L3OCP time to L3OCD time. More...

double	tauGPS
	Fractional part of offset from GPS to GLONASS time. More...

unsigned long	tb
	Instant in Moscow time this data relates to. More...

CommonTime	Toe
	Reference time, combining N4, NT and tb. More...

Triple	vel
	Satellite velocity at tb in km/s. More...

Public Attributes inherited from gnsstk::GLOCNavData
GLOCNavHeader	header
	Common data. More...

Public Attributes inherited from gnsstk::NavData
NavMessageID	signal
	Source signal identification for this navigation message data. More...

CommonTime	timeStamp

std::string	weekFmt

Public Attributes inherited from gnsstk::NavFit
CommonTime	beginFit
	Time at beginning of fit interval. More...

CommonTime	endFit
	Time at end of fit interval. More...

Static Public Attributes
static const GNSSTK_EXPORT double	we = 7.2921151467e-5

Static Public Attributes inherited from gnsstk::NavData
static const GNSSTK_EXPORT std::string	dumpTimeFmt
	Time format used for the dump method (Full). More...

static const GNSSTK_EXPORT std::string	dumpTimeFmtBrief
	Time format used for the dump method (Brief). More...

static GNSSTK_EXPORT gnsstk::SatMetaDataStore *	satMetaDataStore = nullptr
	Set this to a valid store to get PRN->SVN translations in dump(). More...

Private Member Functions
Vector< double >	derivative (const Vector< double > &inState, const Vector< double > &accel, const Vector< double > &lt, bool simplified) const

Additional Inherited Members
Protected Attributes inherited from gnsstk::NavData
double	msgLenSec

Constructor & Destructor Documentation

◆ GLOCNavEph()

gnsstk::GLOCNavEph::GLOCNavEph ( )

Sets the nav message type and all other data members to 0.

Definition at line 55 of file GLOCNavEph.cpp.

Member Function Documentation

◆ clone()

NavDataPtr gnsstk::GLOCNavEph::clone ( ) const

inlineoverridevirtual

Create a deep copy of this object.

Implements gnsstk::NavData.

Definition at line 70 of file GLOCNavEph.hpp.

◆ derivative()

Vector< double > gnsstk::GLOCNavEph::derivative	(	const Vector< double > &	inState,
		const Vector< double > &	accel,
		const Vector< double > &	lt,
		bool	simplified
	)		const

private

Function implementing the derivative of GLONASS orbital model.

See also: ICD GLONASS CDMA General Description Appendix J.2.1.

Parameters

[in]	inState	The input state vector consisting of [x, x', y, y', z, z'].
[in]	accel	The acceleration values, [x'', y'', z''].
[in]	lt	The long-term corrections [ax,ay,az]. Only used when simplified==false.
[in]	simplified	If true, use the simplified algorithm from appendix J.2.1. If false, use the long-term algorithm from J.3.1.

Returns: A vector containing [x',Vx',Y',Vy',Z',Vz'].

Todo:: figure out a reasonable way to handle the fact that FDMA nav uses a less precise value for omega_e. Maybe a different PZ90Ellipsoid class?

Definition at line 378 of file GLOCNavEph.cpp.

◆ dump()

void gnsstk::GLOCNavEph::dump	(	std::ostream &	s,
		DumpDetail	dl
	)		const

overridevirtual

Print the contents of this NavData object in a (usually) human-readable format.

Parameters

[in,out]	s	The stream to write the data to.
[in]	dl	The level of detail the output should contain.

Reimplemented from gnsstk::NavData.

Definition at line 252 of file GLOCNavEph.cpp.

◆ dumpTerse()

void gnsstk::GLOCNavEph::dumpTerse ( std::ostream & s ) const

Dump contents in terse format (DumpDetail==Terse)

Parameters

[in,out] s The stream to write the data to.

Definition at line 363 of file GLOCNavEph.cpp.

◆ factorToSigma()

double gnsstk::GLOCNavEph::factorToSigma ( int8_t factor )

static

Convert the coded factor values as described in ICD section 5.2.2.9 into a pseudorange error (sigma).

Parameters

[in] factor The accuracy factor as broadcast.

Returns: the sigma value in meters, or NaN if factor is invalid.

Definition at line 425 of file GLOCNavEph.cpp.

◆ fixFit()

void gnsstk::GLOCNavEph::fixFit ( )

Fill the beginFit and endFit values for this object.

Precondition: Toe, interval and timeStamp must all be set.

Definition at line 233 of file GLOCNavEph.cpp.

◆ getUserTime()

CommonTime gnsstk::GLOCNavEph::getUserTime ( ) const

overridevirtual

Returns the time when the navigation message would have first been available to the user equipment, i.e. the time at which the final bit of a given broadcast navigation message is received. This is used by NavDataFactoryWithStore::find() in User mode.

Returns: most recent transmit time + 3s.

Reimplemented from gnsstk::NavData.

Definition at line 196 of file GLOCNavEph.cpp.

◆ getXvt()

bool gnsstk::GLOCNavEph::getXvt	(	const CommonTime &	when,
		Xvt &	xvt,
		const ObsID &	oid = `ObsID()`
	)

overridevirtual

Compute the satellites position and velocity at a time.

Note: There are three algorithms in Appendix J of ICD-GLONASS-CDMA General Edition. We follow the recommendation therein of using the simplified algorithm for prediction intervals <=30 minutes, and the long-term algorithm for prediction intervals between 30 minutes and 4 hours. The long-term algorithm requires the data from the LTDMP strings (31-32), so if those are absent for a long-term request, getXvt will indicate failure.

Parameters

[in]	when	The time at which to compute the xvt.
[out]	xvt	The resulting computed position/velocity.
[in]	oid	Value is ignored - GLONASS does not have distinct transmitters.

Returns: true if successful, false if required nav data was unavailable.

Implements gnsstk::OrbitData.

Definition at line 86 of file GLOCNavEph.cpp.

◆ haveLTDMP()

bool gnsstk::GLOCNavEph::haveLTDMP ( ) const

inline

Returns: true if this object has Long-Term Dynamic Model Parameters, needed for best results for prediction intervals > 30 minutes.

Definition at line 132 of file GLOCNavEph.hpp.

◆ validate()

bool gnsstk::GLOCNavEph::validate ( ) const

overridevirtual

Checks the contents of this message against known validity rules as defined in the appropriate ICD.

Note: This does not check the LTDMP, as the ephemeris can still be used for short-term solutions in the case the long-term parameters are unusable.

Returns: true if this message is valid according to ICD criteria.

Reimplemented from gnsstk::GLOCNavData.

Definition at line 75 of file GLOCNavEph.cpp.

Member Data Documentation

◆ acc

Triple gnsstk::GLOCNavEph::acc

Satellite acceleration at tb in km/s**2.

Definition at line 155 of file GLOCNavEph.hpp.

◆ apcOffset

Triple gnsstk::GLOCNavEph::apcOffset

L3OC APC offset from center of mass.

Todo:: implement support for this, see ICD-GLONASS-CDMA General Edition Appendix J, and weep.

Definition at line 158 of file GLOCNavEph.hpp.

◆ clkBias

double gnsstk::GLOCNavEph::clkBias

Satellite clock bias in sec (tau^j).

Definition at line 147 of file GLOCNavEph.hpp.

◆ driftRate

double gnsstk::GLOCNavEph::driftRate

Half rate of relative deviation of carrier freq.

Definition at line 149 of file GLOCNavEph.hpp.

◆ EjE

uint8_t gnsstk::GLOCNavEph::EjE

Age of ephemeris (6-hour intervals).

Definition at line 141 of file GLOCNavEph.hpp.

◆ EjT

uint8_t gnsstk::GLOCNavEph::EjT

Age of clock (6-hour intervals).

Definition at line 142 of file GLOCNavEph.hpp.

◆ FjE

int8_t gnsstk::GLOCNavEph::FjE

Accuracy factors dependent on ephemeris errors.

Definition at line 145 of file GLOCNavEph.hpp.

◆ FjT

int8_t gnsstk::GLOCNavEph::FjT

Accuracy factors dependent on clock errors.

Definition at line 146 of file GLOCNavEph.hpp.

◆ freqBias

double gnsstk::GLOCNavEph::freqBias

Satellite relative frequency bias (gamma^j).

Definition at line 148 of file GLOCNavEph.hpp.

◆ header11

GLOCNavHeader gnsstk::GLOCNavEph::header11

Header (incl xmit time) data from string 11.

Definition at line 163 of file GLOCNavEph.hpp.

◆ header12

GLOCNavHeader gnsstk::GLOCNavEph::header12

Header (incl xmit time) data from string 12.

Definition at line 164 of file GLOCNavEph.hpp.

◆ ltdmp

GLOCNavLTDMP gnsstk::GLOCNavEph::ltdmp

Long-term dynamic model parameters.

Definition at line 161 of file GLOCNavEph.hpp.

◆ Mj

GLOCSatType gnsstk::GLOCNavEph::Mj

What satellite j is and what it transmits.

Definition at line 138 of file GLOCNavEph.hpp.

◆ N4

uint8_t gnsstk::GLOCNavEph::N4

Number of leap years since 1996.

Definition at line 136 of file GLOCNavEph.hpp.

◆ NT

uint16_t gnsstk::GLOCNavEph::NT

Day within four-year interval N4.

Definition at line 137 of file GLOCNavEph.hpp.

◆ pos

Triple gnsstk::GLOCNavEph::pos

Satellite position at tb in km.

Definition at line 153 of file GLOCNavEph.hpp.

◆ PS

uint8_t gnsstk::GLOCNavEph::PS

Number of strings from this type 10 to the next.

Definition at line 139 of file GLOCNavEph.hpp.

◆ RjE

GLOCRegime gnsstk::GLOCNavEph::RjE

Regime for generation of ephemeris data.

Definition at line 143 of file GLOCNavEph.hpp.

◆ RjT

GLOCRegime gnsstk::GLOCNavEph::RjT

Regime for generation of clock data.

Definition at line 144 of file GLOCNavEph.hpp.

◆ step

double gnsstk::GLOCNavEph::step

Integration step for Runge-Kutta algorithm (1 minute by default).

Note: The default value is suggested in ICD-GLONASS-CDMA General Edition Appendix J.

Definition at line 169 of file GLOCNavEph.hpp.

◆ tauc

double gnsstk::GLOCNavEph::tauc

Correction for GLONASS to Moscow time.

Definition at line 150 of file GLOCNavEph.hpp.

◆ taucdot

double gnsstk::GLOCNavEph::taucdot

Rate of correction for GLONASS to Moscow time.

Definition at line 151 of file GLOCNavEph.hpp.

◆ tauDelta

double gnsstk::GLOCNavEph::tauDelta

Offset of L3OCP time to L3OCD time.

Definition at line 159 of file GLOCNavEph.hpp.

◆ tauGPS

double gnsstk::GLOCNavEph::tauGPS

Fractional part of offset from GPS to GLONASS time.

Definition at line 160 of file GLOCNavEph.hpp.

◆ tb

unsigned long gnsstk::GLOCNavEph::tb

Instant in Moscow time this data relates to.

Definition at line 140 of file GLOCNavEph.hpp.

◆ Toe

CommonTime gnsstk::GLOCNavEph::Toe

Reference time, combining N4, NT and tb.

Definition at line 135 of file GLOCNavEph.hpp.

◆ vel

Triple gnsstk::GLOCNavEph::vel

Satellite velocity at tb in km/s.

Definition at line 154 of file GLOCNavEph.hpp.

◆ we

const double gnsstk::GLOCNavEph::we = 7.2921151467e-5

static

Angular velocity of Earth in rad/s. This differs from the PZ90Ellipsoid value in that it has more precision. Based on almanac tests, it's clear that the ICD authors use the truncated value for almanacs, so we're just going to define and use the different value here.

Definition at line 65 of file GLOCNavEph.hpp.

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

Detailed Description

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Private Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ GLOCNavEph()

Member Function Documentation

◆ clone()

◆ derivative()

◆ dump()

◆ dumpTerse()

◆ factorToSigma()

◆ fixFit()

◆ getUserTime()

◆ getXvt()

◆ haveLTDMP()

◆ validate()

Member Data Documentation

◆ acc

◆ apcOffset

◆ clkBias

◆ driftRate

◆ EjE

◆ EjT

◆ FjE

◆ FjT

◆ freqBias

◆ header11

◆ header12

◆ ltdmp

◆ Mj

◆ N4

◆ NT

◆ pos

◆ PS

◆ RjE

◆ RjT

◆ step

◆ tauc

◆ taucdot

◆ tauDelta

◆ tauGPS

◆ tb

◆ Toe

◆ vel

◆ we