topoCoord.h File Reference

This file contains useful functions for geocentric to topographic conversions. More...

Go to the source code of this file.

Functions
void	DtLatLon_to_TopoToGeoc (const DtGeodeticCoord &g, DtDcmRef topoToGeoc)
	Any point on the globe can be used to specify the origin of a specific topographic coordinate system. More...
void	DtLatLon_to_GeocToTopo (const DtGeodeticCoord &g, DtDcmRef geocToTopo)
	The matrix produced by DtLatLon_to_GeocToTopo can be used to rotate a geocentric vector to a topographic vector like this: DtDcmVecMul(geocToTopo, Vgeoc, Vtopo);. More...
void	DtGeocToTopoTransform (double latitude, double longitude, DtCoordTransform *geoc2topo)
	This function can initialize a DtCoordTransform so that it can provide transformations between the geocentric coordinate system, and a particular topographic coordinate system defined by latitude and longitude. More...
double	DtGetHeadingFromGeocentric (DtVector geocLoc, DtTaitBryan geocOri)
	This utility function returns your heading in radians from your geocentric location and orientation. More...
double	DtGetPitchFromGeocentric (DtVector geocLoc, DtTaitBryan geocOri)
	This utility function returns your pitch in radians from your geocentric location and orientation. More...
double	DtGetRollFromGeocentric (DtVector geocLoc, DtTaitBryan geocOri)
	This utility function returns your roll in radians from your geocentric location and orientation. More...

Detailed Description

This file contains useful functions for geocentric to topographic conversions.

Function Documentation

void DtGeocToTopoTransform	(	double	latitude,
		double	longitude,
		DtCoordTransform *	geoc2topo
	)

This function can initialize a DtCoordTransform so that it can provide transformations between the geocentric coordinate system, and a particular topographic coordinate system defined by latitude and longitude.

Latitude and longitude should be in radians.

double DtGetHeadingFromGeocentric	(	DtVector	geocLoc,
		DtTaitBryan	geocOri
	)

This utility function returns your heading in radians from your geocentric location and orientation.

It automatically does the transformation to topographic in order to do this conversion.

double DtGetPitchFromGeocentric	(	DtVector	geocLoc,
		DtTaitBryan	geocOri
	)

This utility function returns your pitch in radians from your geocentric location and orientation.

It automatically does the transformation to topographic in order to do this conversion.

double DtGetRollFromGeocentric	(	DtVector	geocLoc,
		DtTaitBryan	geocOri
	)

This utility function returns your roll in radians from your geocentric location and orientation.

It automatically does the transformation to topographic in order to do this conversion.

void DtLatLon_to_GeocToTopo	(	const DtGeodeticCoord &	g,
		DtDcmRef	geocToTopo
	)

The matrix produced by DtLatLon_to_GeocToTopo can be used to rotate a geocentric vector to a topographic vector like this: DtDcmVecMul(geocToTopo, Vgeoc, Vtopo);.

void DtLatLon_to_TopoToGeoc	(	const DtGeodeticCoord &	g,
		DtDcmRef	topoToGeoc
	)

Any point on the globe can be used to specify the origin of a specific topographic coordinate system.

In VR-Link, a topographic frame is defined with the positive X axis pointing north, the positive Y axis pointing east, and the positive Z axis pointing down. From latitude and longitude, we can produce the rotation matrices that rotate between geocentric and topographic-down orientations. VR-Link uses post-multiplication for its rotation matrices. For example, the matrix produced by DtLatLon_to_TopoToGeoc can be used to rotate a topographic vector to a geocentric vector like this: DtDcmVecMul( topoToGeoc, Vtopo, Vgeoc );