gtsam::gnss::DoubleDifferenceData Struct Reference

Detailed Description

Shared geometry data for double-difference factors.

Holds the four undifferenced observations (rover/base, ref/target satellite), the corresponding satellite ECEF positions at rover and base observation times, and the known base station ECEF position. The struct owns the computation of the observed double-difference and of the geometric DD model range (with Sagnac-corrected geodist) plus its Jacobian w.r.t. the rover or antenna ECEF position.

Used by both the pseudorange and carrier-phase DD factors so the DD geometry/Jacobian implementation is shared.

Public Member Functions
double	observed () const
	Observed DD: (rovRef - baseRef) - (rovTarget - baseTarget) [m].
double	model (const Point3 &rcv, OptionalJacobian< 1, 3 > H_rcv={}) const
	Geometric DD model range and its Jacobian w.r.t.
bool	equals (const DoubleDifferenceData &other, double tol) const

Public Attributes
double	rovRef = 0
	Rover observation for ref satellite [m].
double	baseRef = 0
	Base observation for ref satellite [m].
double	rovTarget = 0
	Rover observation for target satellite [m].
double	baseTarget = 0
	Base observation for target satellite [m].
Point3	satRefRov {0, 0, 0}
	Ref satellite ECEF at rover time [m].
Point3	satTargetRov {0, 0, 0}
	Target satellite ECEF at rover time [m].
Point3	satRefBase {0, 0, 0}
	Ref satellite ECEF at base time [m].
Point3	satTargetBase {0, 0, 0}
	Target satellite ECEF at base time [m].
Point3	basePos {0, 0, 0}
	Base station ECEF position [m].

Member Function Documentation

model()

double gtsam::gnss::DoubleDifferenceData::model	(	const Point3 &	rcv,
		OptionalJacobian< 1, 3 >	H_rcv = {} ) const

Geometric DD model range and its Jacobian w.r.t.

the rover/antenna ECEF position, using Sagnac-corrected geodist for both rover and base sides: model = (geodist(satRefRov, rcv) - geodist(satRefBase, basePos))

• (geodist(satTargetRov, rcv) - geodist(satTargetBase, basePos)) Base-side ranges have no derivative because basePos is fixed.

Parameters

[in]	rcv	Rover (or antenna) ECEF position [m].
[out]	H_rcv	Optional 1x3 Jacobian of the model w.r.t. rcv.

Returns

Geometric DD model range [m].

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

• /tmp/gtsam-4.3.0-doxygen.rsXPUS/source/gtsam/navigation/GnssCommon.h
• /tmp/gtsam-4.3.0-doxygen.rsXPUS/source/gtsam/navigation/GnssCommon.cpp