Detailed Description

This class provides a factory that processes PackedNavBits data containing BeiDou D2 NAV data as defined in the BeiDou ICD. The results of the addData method (in the navOut argument) may contain any number of BDSD2NavAlm, BDSD2NavEph, BDSD2NavHealth or BDSD2NavTimeOffset objects, according to what data is fed to the method and what data is requested via the validity and type filters (see PNBNavDataFactory).

The D2 NAV data structure is set up to provide almanac and health data for PRNs >30 by flagging it in other almanac pages using the AmEpID. My interpretation of the ICD, and data seems to back this up, is that AmEpID is only meaningful when it is equal to 3 (b11) in subframe 4, pages 11-24. In this case, the subframe 5 page (11-24) in that same frame will correspond to the information in sections 5.2.4.14, 5.2.4.15 and 5.2.4.17. AmEpID can be set to 3 for other pages, but it doesn't seem to carry a meaning in that context.

With respect to validity checking, the following checks are performed:

Default almanac page data (data is all zeroes)

The following data are discarded and never returned due to the fact that attempting to provide the data to users would result in exceptions and other software internal errors:

Almanac pages with no matching toa in a subframe 5, page 8, needed for the WNa

Currently ignored:

subframe 2 (SatH2, BDID, UDREI, RURAI, delta t)
subframe 3 (RURAI, delta t)
subframe 4 (BDEpID, BDID, UDREI, RURAI, delta t)
subframe 5 (regional iono; pages 35-60,95-116 are processed)

Definition at line 85 of file PNBBDSD2NavDataFactory.hpp.

#include <PNBBDSD2NavDataFactory.hpp>

Inheritance diagram for gnsstk::PNBBDSD2NavDataFactory:

[legend]

Classes
class	AmEpID
	Store transmit time and corresponding AmEpID for amEpIDMap. More...

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

void	dumpState (std::ostream &s) const

bool	filterTimeOffset (double a0, double a1)
	Return true if a0 and a1 are zero and double 0 filtering is enabled. More...

bool	processAlm (unsigned pnum, const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

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

bool	processSF5Pg101 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processSF5Pg102 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processSF5Pg116 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processSF5Pg35 (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut)

bool	processSF5Pg36 (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)

Static Public Member Functions
static bool	isAlmDefault (const PackedNavBitsPtr &navIn)

Protected Types
typedef std::shared_ptr< BDSD2NavAlm >	AlmPtr
	Alias for almanac objects. More...

typedef std::list< AlmPtr >	AlmPtrList
	Alias for list of almanac objects. More...

Protected Member Functions
bool	finishAlm (AlmPtr &alm, bool fromWNa, const NavSatelliteID &key, NavDataPtrList &navOut)

void	finishAlm (bool fromWNa, const NavSatelliteID &key, NavDataPtrList &navOut)

void	makeHealth (const PackedNavBitsPtr &navIn, NavDataPtrList &navOut, unsigned long subjID, unsigned startBit1, unsigned numBits1, unsigned startBit2=0, unsigned numBits2=0)

Protected Attributes
std::map< NavSatelliteID, AlmPtrList >	almAcc

std::map< NavSatelliteID, AmEpID >	amEpIDMap

std::map< NavSatelliteID, std::vector< PackedNavBitsPtr > >	ephAcc

std::map< unsigned, BDSWeekSecond >	fullWNaMap

std::map< NavSatelliteID, uint16_t >	heaAcc

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 Typedef Documentation

◆ AlmPtr

typedef std::shared_ptr<BDSD2NavAlm> gnsstk::PNBBDSD2NavDataFactory::AlmPtr

protected

Alias for almanac objects.

Definition at line 227 of file PNBBDSD2NavDataFactory.hpp.

◆ AlmPtrList

typedef std::list<AlmPtr> gnsstk::PNBBDSD2NavDataFactory::AlmPtrList

protected

Alias for list of almanac objects.

Definition at line 229 of file PNBBDSD2NavDataFactory.hpp.

Member Function Documentation

◆ addData()

bool gnsstk::PNBBDSD2NavDataFactory::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.

Todo:: Implement a parity check

Implements gnsstk::PNBNavDataFactory.

Definition at line 71 of file PNBBDSD2NavDataFactory.cpp.

◆ dumpState()

void gnsstk::PNBBDSD2NavDataFactory::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 976 of file PNBBDSD2NavDataFactory.cpp.

◆ filterTimeOffset()

bool gnsstk::PNBBDSD2NavDataFactory::filterTimeOffset	(	double	a0,
		double	a1
	)

inline

Return true if a0 and a1 are zero and double 0 filtering is enabled.

Definition at line 197 of file PNBBDSD2NavDataFactory.hpp.

◆ finishAlm() [1/2]

bool gnsstk::PNBBDSD2NavDataFactory::finishAlm	(	PNBBDSD2NavDataFactory::AlmPtr &	alm,
		bool	fromWNa,
		const NavSatelliteID &	key,
		NavDataPtrList &	navOut
	)

protected

Attempt to complete a single almanac object.

Parameters

[in,out]	alm	A single almanac to potentially complete (set the "Toe"/"Toc" which are really the toa, health and fit interval).
[in]	fromWNa	If true, this function is being called after processing subframe 5 page 8, which contains the WNa, which results in special processing.
[in]	key	The key used to look up the WNa for the almanac (the NavSatelliteID with the subject sat set to 0).
[out]	navOut	Any completed almanacs will be stored in here.

Returns: true if the given alm was completed or should be treated as such.

Todo:: see comment in BDSD2NavHealth::getHealth()

Todo:: see comment in BDSD2NavHealth::getHealth()

Definition at line 909 of file PNBBDSD2NavDataFactory.cpp.

◆ finishAlm() [2/2]

void gnsstk::PNBBDSD2NavDataFactory::finishAlm	(	bool	fromWNa,
		const NavSatelliteID &	key,
		NavDataPtrList &	navOut
	)

protected

Search through the internal store of almanac data for almanacs that can be completed.

Parameters

[in]	fromWNa	If true, this function is being called after processing subframe 5 page 8, which contains the WNa, which results in special processing.
[in]	key	The key used to look up the WNa for the almanac (the NavSatelliteID with the subject sat set to 0).
[out]	navOut	Any completed almanacs will be stored in here.

Definition at line 889 of file PNBBDSD2NavDataFactory.cpp.

◆ isAlmDefault()

bool gnsstk::PNBBDSD2NavDataFactory::isAlmDefault ( const PackedNavBitsPtr & navIn )

static

Determine if a given page contains default data.

Note: This method does not check to see if navIn is an almanac page, only if bits are unset.

Parameters

[in] navIn The as-broadcast bits.

Returns: true if bits 90-289 are unset.

Definition at line 863 of file PNBBDSD2NavDataFactory.cpp.

◆ makeHealth()

void gnsstk::PNBBDSD2NavDataFactory::makeHealth	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut,
		unsigned long	subjID,
		unsigned	startBit1,
		unsigned	numBits1,
		unsigned	startBit2 = `0`,
		unsigned	numBits2 = `0`
	)

protected

Create a BDSD2NavHealth object from the 9 bits of almanac health data. This method can be used for consecutive bits by specifying startBit2=0 and numBits2=0. Otherwise, if the health bits are split into to pieces, startBit1/2 and numBits1/2 are both used.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	A BDSD2NavAlm object is added to this list (no checking is done at this level to see if health objects are desired).
[in]	subjID	The PRN ID of the satellite to which these health bits pertain.
[in]	startBit1	The first bit in navIn containing the MSBs of the health information.
[in]	numBits1	The number of bits in the MSB portion of the health bits.
[in]	startBit2	The first bit in navIn containing the LSBs of the health information.
[in]	numBits2	The number of bits in the LSB portion of the health bits.

Definition at line 832 of file PNBBDSD2NavDataFactory.cpp.

◆ processAlm()

bool gnsstk::PNBBDSD2NavDataFactory::processAlm	(	unsigned	pnum,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process almanac messages. An almanac is placed in navOut, if such processing is enabled.

Parameters

[in]	pnum	The page number (1-120) pertaining to navIn.
[in]	navIn	The as-broadcast almanac bits.
[out]	navOut	If an almanac is completed and the data is requested, this will contain a BDSD2NavAlm object.

Returns: false on error.

Definition at line 167 of file PNBBDSD2NavDataFactory.cpp.

◆ processEph()

bool gnsstk::PNBBDSD2NavDataFactory::processEph	(	unsigned long	pgid,
		const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process ephemeris messages. A combination of ephemeris, iono and ISC objects are placed in navOut, depending on the type filter settings and input subframe.

Parameters

[in]	pgid	Page number (1-10) of the input data.
[in]	navIn	The as-broadcast ephemeris bits.
[out]	navOut	If an ephemeris is completed and the data is requested, this will contain a BDSD2NavEph object. If the input is subframe 1 and data is requested, this will contain BDSD2NavIono and/or BDSD2NavISC objects.

Returns: false on error.

Bug:: I can't find in the ICD where it says what the scale factor is for the SOW field. It's stored in 20 bits even though 604800 only requires 19 bits.

Definition at line 302 of file PNBBDSD2NavDataFactory.cpp.

◆ processSF5Pg101()

bool gnsstk::PNBBDSD2NavDataFactory::processSF5Pg101	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process subframe 5 page 101 which contains time offsets between BeiDou and other GNSSes.

Note: The ICD indicates this is currently unused. As such, the returned data will be marked invalid until real (non-zero) data is broadcast by BeiDou.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	If time offset data is requested, this will contain multiple time offset objects.

Returns: false on error.

Todo:: figure out what the reference time is supposed to be, which is not a high priority as the ICD itself says "Not broadcast temporarily".

Definition at line 656 of file PNBBDSD2NavDataFactory.cpp.

◆ processSF5Pg102()

bool gnsstk::PNBBDSD2NavDataFactory::processSF5Pg102	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process subframe 5 page 102 which contains the time offset between BeiDou and UTC.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	If time offset data is requested, this will contain a single time offset object.

Returns: false on error.

Definition at line 730 of file PNBBDSD2NavDataFactory.cpp.

◆ processSF5Pg116()

bool gnsstk::PNBBDSD2NavDataFactory::processSF5Pg116	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process subframe 5 page 116 which may contain health data for the extended constellation. This data is only present when the AmEpID bits are set to 3 and the AmID bits in this subframe 5 are non-zero.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	If an almanac is completed and the data is requested, this will contain one or more BDSD2NavAlm objects. If health data is requested, this will contain multiple health objects.

Returns: false on error.

Definition at line 776 of file PNBBDSD2NavDataFactory.cpp.

◆ processSF5Pg35()

bool gnsstk::PNBBDSD2NavDataFactory::processSF5Pg35	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process subframe 5 page 35 which contains health data.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	If an almanac is completed and the data is requested, this will contain one or more BDSD2NavAlm objects. If health data is requested, this will contain multiple health objects.

Returns: false on error.

Definition at line 558 of file PNBBDSD2NavDataFactory.cpp.

◆ processSF5Pg36()

bool gnsstk::PNBBDSD2NavDataFactory::processSF5Pg36	(	const PackedNavBitsPtr &	navIn,
		NavDataPtrList &	navOut
	)

Process subframe 5 page 36 which contains health data as well as the WNa for almanacs.

Parameters

[in]	navIn	The as-broadcast bits.
[out]	navOut	If an almanac is completed and the data is requested, this will contain one or more BDSD2NavAlm objects. If health data is requested, this will contain multiple health objects.

Returns: false on error.

Definition at line 597 of file PNBBDSD2NavDataFactory.cpp.

◆ resetState()

void gnsstk::PNBBDSD2NavDataFactory::resetState ( )

overridevirtual

Reset the state of the data accumulator. Most PNBNavDataFactory child classes will maintain some state to assemble data prior to processing. 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 880 of file PNBBDSD2NavDataFactory.cpp.

Member Data Documentation

◆ almAcc

std::map<NavSatelliteID, AlmPtrList> gnsstk::PNBBDSD2NavDataFactory::almAcc

protected

Accumulate almanac orbital element pages (sf 4 pg 1-24, sf 5 pg 1-6) until a page sf 5 pg 8 becomes available to properly set the WNa. Key is the transmitting PRN (only xmitSat is set, sat is ignored).

Definition at line 237 of file PNBBDSD2NavDataFactory.hpp.

◆ amEpIDMap

std::map<NavSatelliteID, AmEpID> gnsstk::PNBBDSD2NavDataFactory::amEpIDMap

protected

Keep track of the most recent AmEpID for a given NavSatelliteID. This allows us to determine whether or not to emit an almanac for subframe 5, pages 11-23, or health for subframe 5, page 24.

Definition at line 242 of file PNBBDSD2NavDataFactory.hpp.

◆ ephAcc

std::map<NavSatelliteID, std::vector<PackedNavBitsPtr> > gnsstk::PNBBDSD2NavDataFactory::ephAcc

protected

Map PRN to a vector of PackedNavBits for accumulating ephemeris data, where index 0 is subframe 1 and so on.

Definition at line 245 of file PNBBDSD2NavDataFactory.hpp.

◆ fullWNaMap

std::map<unsigned, BDSWeekSecond> gnsstk::PNBBDSD2NavDataFactory::fullWNaMap

protected

Map transmit PRN to fully qualified week/second (WNa/toa). This is set by sf 5 pg 8.

Definition at line 232 of file PNBBDSD2NavDataFactory.hpp.

◆ heaAcc

std::map<NavSatelliteID, uint16_t> gnsstk::PNBBDSD2NavDataFactory::heaAcc

protected

Map PRN to health status to use in almanac objects. The data are pulled from sf 5, pg 7-8. Unfortunately, only pg 8 has toa in it, so really about the best we can do is store the most recent health bits and use them.

Definition at line 250 of file PNBBDSD2NavDataFactory.hpp.

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

Detailed Description

Classes

Public Member Functions

Static Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Member Typedef Documentation

◆ AlmPtr

◆ AlmPtrList

Member Function Documentation

◆ addData()

◆ dumpState()

◆ filterTimeOffset()

◆ finishAlm() [1/2]

◆ finishAlm() [2/2]

◆ isAlmDefault()

◆ makeHealth()

◆ processAlm()

◆ processEph()

◆ processSF5Pg101()

◆ processSF5Pg102()

◆ processSF5Pg116()

◆ processSF5Pg35()

◆ processSF5Pg36()

◆ resetState()

Member Data Documentation

◆ almAcc

◆ amEpIDMap

◆ ephAcc

◆ fullWNaMap

◆ heaAcc