DtReferenceEllipsoid Class Reference

Instances of this class are used to store a particular mapDatum and perform useful calculations based on this map -- specifically it can be used to convert between geodetic and geocentric coordinates using the given reference ellipsoid (which is defined by a DtMapDatum). More...

Collaboration diagram for DtReferenceEllipsoid:

List of all members.

Public Member Functions
	DtReferenceEllipsoid (const DtMapDatum &datum)
virtual	~DtReferenceEllipsoid ()
void	useMapDatum (const DtMapDatum &datum)
const DtMapDatum &	mapDatum () const
void	geocentricToGeodetic (const DtVector &gc, DtVector &gd) const
void	geodeticToGeocentric (const DtVector &gd, DtVector &gc) const
Static Public Member Functions
static void	setMaxIterationsForConvergence (unsigned int maxItr)
	sets the maximum number of iterations to preform when converting from geocentric to geodetic.
static unsigned int	maxIterationsForConvergence ()
	Returns the maximum number of iterations used in geocentric_to_geodetic().
Protected Member Functions
void	initialize_ellipsoid (double a, double f)
void	geo_to_rad (double deg, double min, double sec, double *radian) const
void	rad_to_geo (double radian, double *deg, double *min, double *sec) const
void	geodetic_to_geocentric (double lat, double lon, double height, double *x, double *y, double *z) const
void	geocentric_to_geodetic (double xp, double yp, double zp, double *lat, double *lon, double *height) const
	Performs the transformation between geocentric and geodetic coordinate systems.
Protected Attributes
DtMapDatum	myMapDatum
int	myInited
double	ellipse_a
double	ellipse_a_sq
	equatorial radius
double	ellipse_f
	radius squared
double	ellipse_b
	flattening (a-b)/a
double	ellipse_b_sq
	polar semi-diameter
double	ellipse_a_sq_over_b
	polar semi-diameter squared
double	ellipse_e
	a*a/b
double	ellipse_c1
	ellipticity 2f-f*f
Static Protected Attributes
static unsigned int	theMaxIterationsForConvergence

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Detailed Description

Instances of this class are used to store a particular mapDatum and perform useful calculations based on this map -- specifically it can be used to convert between geodetic and geocentric coordinates using the given reference ellipsoid (which is defined by a DtMapDatum).

By default, VR-Link creates a global ellipsoid object that is used for geodetic coordinates conversions. However, users can choose to define and maintain their own ellipsoids and then can explicitly pass the ellipsoid to a geodetic coordinate.

Conversions between geocentric and geodetic coordinates depend on the particular MapDatum used. The default is DtWGS84, but you can set the current global MapDatum using DtUseMapDatum . See mapDatum.h for more details

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Constructor & Destructor Documentation

DtReferenceEllipsoid::DtReferenceEllipsoid

(

const DtMapDatum &

datum

)

virtual DtReferenceEllipsoid::~DtReferenceEllipsoid

(

)

[virtual]

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Member Function Documentation

void DtReferenceEllipsoid::geo_to_rad	(	double	deg,
		double	min,
		double	sec,
		double *	radian
	)		const [protected]

void DtReferenceEllipsoid::geocentric_to_geodetic	(	double	xp,
		double	yp,
		double	zp,
		double *	lat,
		double *	lon,
		double *	height
	)		const [protected]

Performs the transformation between geocentric and geodetic coordinate systems.

This routine receives geocentric coordinates (X, Y, Z) in meters and converts it into geodetic coordinates given in latitude, longitude, and height. This algorithm uses Newton- Raphson's convergence algorithm, and will stop iteration at values less than 50 cm. Will also stop iteration when maxIteractionsForConvergence is reached.

Exceptions:

DtException

when maximum iterations reached.

void DtReferenceEllipsoid::geocentricToGeodetic	(	const DtVector &	gc,
		DtVector &	gd
	)		const

void DtReferenceEllipsoid::geodetic_to_geocentric	(	double	lat,
		double	lon,
		double	height,
		double *	x,
		double *	y,
		double *	z
	)		const [protected]

void DtReferenceEllipsoid::geodeticToGeocentric	(	const DtVector &	gd,
		DtVector &	gc
	)		const

void DtReferenceEllipsoid::initialize_ellipsoid	(	double	a,
		double	f
	)		[protected]

const DtMapDatum& DtReferenceEllipsoid::mapDatum

(

)

const

static unsigned int DtReferenceEllipsoid::maxIterationsForConvergence

(

)

[static]

Returns the maximum number of iterations used in geocentric_to_geodetic().

void DtReferenceEllipsoid::rad_to_geo	(	double	radian,
		double *	deg,
		double *	min,
		double *	sec
	)		const [protected]

static void DtReferenceEllipsoid::setMaxIterationsForConvergence

(

unsigned int

maxItr

)

[static]

sets the maximum number of iterations to preform when converting from geocentric to geodetic.

This is used by the geocentric_to_geodetic() function. The default value is 5000.

void DtReferenceEllipsoid::useMapDatum

(

const DtMapDatum &

datum

)

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Member Data Documentation

double DtReferenceEllipsoid::ellipse_a [protected]

double DtReferenceEllipsoid::ellipse_a_sq [protected]

equatorial radius

double DtReferenceEllipsoid::ellipse_a_sq_over_b [protected]

polar semi-diameter squared

double DtReferenceEllipsoid::ellipse_b [protected]

flattening (a-b)/a

double DtReferenceEllipsoid::ellipse_b_sq [protected]

polar semi-diameter

double DtReferenceEllipsoid::ellipse_c1 [protected]

ellipticity 2f-f*f

double DtReferenceEllipsoid::ellipse_e [protected]

a*a/b

double DtReferenceEllipsoid::ellipse_f [protected]

radius squared

int DtReferenceEllipsoid::myInited [protected]

DtMapDatum DtReferenceEllipsoid::myMapDatum [protected]

unsigned int DtReferenceEllipsoid::theMaxIterationsForConvergence [static, protected]

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

• refEllipsoid.h