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:

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

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

Constructor & Destructor Documentation

DtReferenceEllipsoid::DtReferenceEllipsoid

(

const DtMapDatum &

datum

)

virtual DtReferenceEllipsoid::~DtReferenceEllipsoid ( )

virtual

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

)

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

staticprotected

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

• referenceEllipsoid.h