Detailed Description

This class provides a factory that processes PackedNavBits data containing GPS CNav (Civil Nav, aka data ID 4) data as defined in IS-GPS-200 section 30. The results of the addData method (in the navOut argument) may contain any number of GPSCNavAlm, GPSCNavEph, GPSCNavHealth or GPSCNavTimeOffset objects, according to what data is fed to the method and what data is requested via the validity and type filters (see PNBNavDataFactory).

Note: Currently validity is not checked in any way in this class.; Currently only message types 10, 11, 30, 32 and 33 are being broadcast by the constellation. As such, no further effort is going to be spent at this time on decoding messages outside this set. GPSCNavAlm data structure and decoding was already implemented by this time, but the data isn't being transmitted and has not been tested.

Definition at line 65 of file PNBGPSCNavDataFactory.hpp.

#include <PNBGPSCNavDataFactory.hpp>

Inheritance diagram for gnsstk::PNBGPSCNavDataFactory:

[legend]

Public Member Functions
bool	addData (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut, double cadence=-1) override

void	dumpState (std::ostream &s) const

bool	process12 (unsigned msgType, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	process30 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	process31 (unsigned msgType, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	process33 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	process35 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processAlmOrb (unsigned msgType, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processEph (unsigned msgType, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processRedAlmOrb (unsigned msgType, unsigned offset, unsigned pre, bool alert, unsigned wna, double toa, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

void	resetState () override

Public Member Functions inherited from gnsstk::PNBNavDataFactory
	PNBNavDataFactory ()

virtual void	setControl (const FactoryControl &ctrl)

virtual void	setTypeFilter (const NavMessageTypeSet &nmts)

virtual void	setValidityFilter (NavValidityType nvt)

Protected Attributes
std::map< unsigned, std::vector< PackedNavBitsPtr > >	ephAcc

Protected Attributes inherited from gnsstk::PNBNavDataFactory
FactoryControl	factControl
	Configuration for the behavior of this factory. More...

NavValidityType	navValidity
	Determines how the factory should filter added data. More...

bool	processAlm
	If true, almanac data will be output by addData. More...

bool	processEph
	If true, ephemeris data will be output by addData. More...

bool	processHea
	If true, health data will be output by addData. More...

bool	processIono
	If true, ionospheric data will be output by addData. More...

bool	processISC
	If true, inter-signal correction data will be output by addData. More...

bool	processTim
	If true, time offset data will be output by addData. More...

Member Function Documentation

◆ addData()

bool gnsstk::PNBGPSCNavDataFactory::addData	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut,
		double	cadence = `-1`
	)

overridevirtual

Process a PackedNavBits object, producing NavData objects as appropriate.

Parameters

[in]	navIn	The PackedNavBits data to process.
[out]	navOut	Any resulting NavData objects that were completed, usually as a result of adding navIn to the set of data.
[in]	cadence	This value is ignored in this class.

Returns: false on error.

Implements gnsstk::PNBNavDataFactory.

Definition at line 57 of file PNBGPSCNavDataFactory.cpp.

◆ dumpState()

void gnsstk::PNBGPSCNavDataFactory::dumpState ( std::ostream & s ) const

For debugging purposes, dump the sizes of the accumulator maps.

Parameters

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

Definition at line 895 of file PNBGPSCNavDataFactory.cpp.

◆ process12()

bool gnsstk::PNBGPSCNavDataFactory::process12	(	unsigned	msgType,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 12. This includes reduced almanac data.

Parameters

[in]	msgType	Type of the message that contains the packet being decoded. Used to determine the subject satellite in QZSS.
[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavTimeOffset object generated from navIn.

Returns: true if successful.

Definition at line 559 of file PNBGPSCNavDataFactory.cpp.

◆ process30()

bool gnsstk::PNBGPSCNavDataFactory::process30	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 30. This includes ionospheric correction information for single-frequency users.

Parameters

[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavIono object generated from navIn.

Returns: true if successful.

Definition at line 578 of file PNBGPSCNavDataFactory.cpp.

◆ process31()

bool gnsstk::PNBGPSCNavDataFactory::process31	(	unsigned	msgType,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 31. This includes reduced almanac data.

Parameters

[in]	msgType	Type of the message that contains the packet being decoded. Used to determine the subject satellite in QZSS.
[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavTimeOffset object generated from navIn.

Returns: true if successful.

Definition at line 630 of file PNBGPSCNavDataFactory.cpp.

◆ process33()

bool gnsstk::PNBGPSCNavDataFactory::process33	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 33. This includes GPS-UTC time offset data.

Parameters

[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavTimeOffset object generated from navIn.

Returns: true if successful.

Definition at line 799 of file PNBGPSCNavDataFactory.cpp.

◆ process35()

bool gnsstk::PNBGPSCNavDataFactory::process35	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 35. This includes GPS-GNSS time offset data.

Parameters

[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavTimeOffset object generated from navIn.

Returns: true if successful.

Note: this is defined in IS-QZSS. Not sure if we should really be checking to make sure the signal is from a QZSS satellite.

Definition at line 839 of file PNBGPSCNavDataFactory.cpp.

◆ processAlmOrb()

bool gnsstk::PNBGPSCNavDataFactory::processAlmOrb	(	unsigned	msgType,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process message type 37 (GPS, QZSS) or 53 (QZSS).

Parameters

[in]	msgType	The CNAV message type.
[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavAlm and/or GPSCNavHealth objects generated from navIn.

Returns: true if successful (navOut may still be empty).

Todo:: I'm not entirely sure what's appropriate here. The source signal is actually L2C CNAV but it's broadcasting signal status for L1 signals that don't have CNAV.

Todo:: apply 13-bit week rollover adjustment, not 10-bit. Must be completed by January, 2137 :-)

Definition at line 391 of file PNBGPSCNavDataFactory.cpp.

◆ processEph()

bool gnsstk::PNBGPSCNavDataFactory::processEph	(	unsigned	msgType,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process ephemeris messages 1-2. When a complete and consistent ephemeris is accumulated in ephAcc, that ephemeris is placed in navOut.

Parameters

[in]	msgType	The CNAV message type (10-11).
[in]	navIn	The as-broadcast ephemeris message bits.
[out]	navOut	If an ephemeris is completed, this will contain a GPSCNavEph object.

Returns: false on error.

Todo:: Should we ignore the PNB satellite ID and just use the PRN in the nav message, or maybe compare the two as an validity check?

Todo:: Is this strictly relevant for ephemeris assembly? Seems like if these are rebroadcast messages they're not going to correspond to the ephemeris data being broadcast by QZSS.

Todo:: I'm not entirely sure what's appropriate here. The source signal is actually L2C CNAV but it's broadcasting signal status for L1 signals that don't have CNAV.

Note: Some data elements, e.g. toe, are stored internally as floating point, but are treated as integers in the encoded message. This is not a mistake. It's mostly due to how the scaling is handled for the quantity, i.e. linear scaling vs fractional (ldexp).

Todo:: apply 13-bit week rollover adjustment, not 10-bit. Must be completed by January, 2137 :-)

Todo:: GEO QZSS satellites use a different OMEGAdot reference, but I have yet to figure out how to determine if a QZSS satellite is GEO or QZO

Definition at line 137 of file PNBGPSCNavDataFactory.cpp.

◆ processRedAlmOrb()

bool gnsstk::PNBGPSCNavDataFactory::processRedAlmOrb	(	unsigned	msgType,
		unsigned	offset,
		unsigned	pre,
		bool	alert,
		unsigned	wna,
		double	toa,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process a single reduced almanac packed from either message type 12 or 31 (or, for QZSS, including message types 28 and 47).

Parameters

[in]	msgType	Type of the message that contains the packet being decoded. Used to determine the subject satellite in QZSS.
[in]	offset	The position of the first bit of the reduced almanac packet within navIn.
[in]	pre	The 8-bit preamble taken from the message start.
[in]	alert	The 1-bit alert flag taken from the message start.
[in]	wna	The WNa (almanac week number) as extracted from the message. This value is shared across the message and applies to all packets in a given message.
[in]	toa	The almanac reference time in seconds of week (see wna).
[in]	navIn	The PackedNavBits data containing the message.
[out]	navOut	The GPSCNavRedAlm object generated from navIn.

Returns: true if successful.

Todo:: I'm not entirely sure what's appropriate here. The source signal is actually L2C CNAV but it's broadcasting signal status for L1 signals that don't have CNAV.

Todo:: apply 13-bit week rollover adjustment, not 10-bit. Must be completed by January, 2137 :-)

Definition at line 646 of file PNBGPSCNavDataFactory.cpp.

◆ resetState()

void gnsstk::PNBGPSCNavDataFactory::resetState ( )

inlineoverridevirtual

Reset the state of the data accumulator. This method is intended to be used to clear out that intermediate data to start from a fresh state, e.g. if you're loading discontinuous data.

Implements gnsstk::PNBNavDataFactory.

Definition at line 172 of file PNBGPSCNavDataFactory.hpp.

Member Data Documentation

◆ ephAcc

std::map<unsigned, std::vector<PackedNavBitsPtr> > gnsstk::PNBGPSCNavDataFactory::ephAcc

protected

Map GPS PRN to a vector of PackedNavBits for accumulating ephemeris data, where index 0 is message 10 and so on.

Definition at line 182 of file PNBGPSCNavDataFactory.hpp.

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

Detailed Description

Public Member Functions

Protected Attributes

Member Function Documentation

◆ addData()

◆ dumpState()

◆ process12()

◆ process30()

◆ process31()

◆ process33()

◆ process35()

◆ processAlmOrb()

◆ processEph()

◆ processRedAlmOrb()

◆ resetState()

Member Data Documentation

◆ ephAcc