Position Class Reference
[Geodetic coordinates and geoids]

#include <Position.hpp>

Inheritance diagram for Position:

[legend]Collaboration diagram for Position:

Detailed Description

A position representation class for common 3D geographic position formats, including geodetic (geodetic latitude, longitude, and height above the geoid) geocentric (geocentric latitude, longitude, and radius from Earth's center), cartesian (Earth-centered, Earth-fixed) and spherical (theta,phi,radius).

Internally, the representation of Position consists of three coordinate values (double), two doubles from a geoid model (see below, storing these doubles is preferred over adding GeoidModel to calling arguments everywhere), a flag of type 'enum CoordinateSystem' giving the coordinate system, and a tolerance for use in comparing Positions. Class Position inherits from class Triple, which is how the coordinate values are stored (Triple actually uses std::valarray<double> of length 3). It is important to note that Triple:: routines are properly used by Positions ONLY in the Cartesian coordinate system.

Only geodetic coordinates depend on a geoid, and then (for an ellipsoidal geoid) only on the semi-major axis of the Earth and the square of its eccentricity. Input of this geoid information (usually a pointer to a GeoidModel) is required by functions involving constructors of, or transformation to or from, Geodetic coordinates. However since a default is supplied (WGS84), the user need never deal with geiods unless desired. In fact, if the geodetic coordinate system is avoided, the Position class can be interpreted simply as 3D vectors in any context, particularly since the class inherits from Triple, which includes many vector manipulation routines (although the Triple:: routines assume Cartesian coordinates). Even the requirement that lengths (radius, height and the cartesian coordinates) have units of meters is required only if geodetic coordinates are used (because the semi-major axis in GeoidModel is in meters); without using Geodetic one could apply the class using any units for length as long as setTolerance() is called appropriately.

Position relies on a series of fundamental routines to transform from one coordinate system to another, these include, for example void Position::convertGeodeticToCartesian(const Triple& llh, Triple& xyz, const double A, const double eccSq); void Position::convertSphericalToCartesian(const Triple& tpr, Triple& xyz); These functions use Triple in the calling arguments.

Position will throw exceptions (gpstk::GeometryException) on bad input (e.g. negative radius or latitude > 90 degrees); otherwise the class attempts to handle all points, even the pole and the origin, consistently and without throwing exceptions. At or very near the poles, the transformation routines will set latitude = +/-90 degrees, which is theta = 0 or 180, and (arbitrarily) longitude = 0. At or very near the origin, the transformation routines will set latitude = 0, which is theta = 90, and (arbitrarily) longitude = 0; radius will be set to zero and geodetic height will be set to -radius(Earth) (= -6378137.0 in WGS84). The tolerance used in testing 'at or near the pole or origin' is radius < POSITION_TOLERANCE/5. Note that this implies that a Position that is very near the origin may be SET to the exact origin by the transformation routines, and that thereby information about direction (e.g. latitude and longitude) may be LOST. The user is warned to be very careful when working near either the pole or the origin.

Position includes setToString() and printf() functions similar to those in gpstk::DayTime; this allows flexible and powerful I/O of Position to strings and streams.

See also:: positiontest.cpp for examples.

Definition at line 118 of file Position.hpp.

Public Types

enum CoordinateSystem {
Unknown = 0, Geodetic, Geocentric, Cartesian,
Spherical
}

The coordinate systems supported by Position. More...

Public Member Functions

std::string getSystemName () throw ()

return string giving name of coordinate system

Position & setTolerance (const double tol) throw ()

Sets the tolerance for output and comparisons, for this object only.

Position () throw ()

Default constructor.

Position (const double &a, const double &b, const double &c, CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)

Explicit constructor.

Position (const double ABC[3], CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)

Explicit constructor.

Position (const Triple &ABC, CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)

Explicit constructor.

Position (const Xvt &xvt) throw ()

Explicit constructor from Xvt.

~Position () throw ()

Destructor.

Position & operator-= (const Position &right) throw ()

Subtract a Position from this Position.

Position & operator+= (const Position &right) throw ()

Add a Position to this Position.

bool operator== (const Position &right) const throw ()

Equality operator.

bool operator!= (const Position &right) const throw ()

Inequality operator.

Position transformTo (CoordinateSystem sys) throw ()

Transform coordinate system.

Position asGeodetic () throw ()

Convert to geodetic coordinates (does nothing if system == Geodetic already).

Position asGeodetic (GeoidModel *geoid) throw (GeometryException)

Convert to another geoid, then to geodetic coordinates.

Position asECEF () throw ()

Convert to cartesian coordinates (does nothing if system == Cartesian already).

double X () const throw ()

return X coordinate (meters)

double Y () const throw ()

return Y coordinate (meters)

double Z () const throw ()

return Z coordinate (meters)

double geodeticLatitude () const throw ()

return geodetic latitude (degrees North).

double geocentricLatitude () const throw ()

return geocentric latitude (degrees North); equal to 90 degress - theta in regular spherical coordinates.

double theta () const throw ()

return spherical coordinate theta in degrees

double phi () const throw ()

return spherical coordinate phi in degrees

double longitude () const throw ()

return longitude (degrees East); equal to phi in regular spherical coordinates.

double radius () const throw ()

return distance from the center of Earth (meters), Same as radius in spherical coordinates.

double height () const throw ()

return height above ellipsoid (meters) (Geodetic).

CoordinateSystem getCoordinateSystem () const throw ()

return the coordinate system for this Position

double getGeodeticLatitude () const throw ()

return geodetic latitude (deg N)

double getGeocentricLatitude () const throw ()

return geocentric latitude (deg N)

double getLongitude () const throw ()

return longitude (deg E) (either geocentric or geodetic)

double getAltitude () const throw ()

return height above ellipsoid (meters)

double getHeight () const throw ()

return height above ellipsoid (meters)

double getX () const throw ()

return ECEF X coordinate (meters)

double getY () const throw ()

return ECEF Y coordinate (meters)

double getZ () const throw ()

return ECEF Z coordinate (meters)

double getTheta () const throw ()

return spherical coordinate angle theta (deg) (90 - geocentric latitude)

double getPhi () const throw ()

return spherical coordinate angle phi (deg) (same as longitude)

double getRadius () const throw ()

return radius

void setGeoidModel (const GeoidModel *geoid) throw (GeometryException)

Set the geoid values for this Position given a geoid.

Position & setGeodetic (const double lat, const double lon, const double ht, const GeoidModel *geoid=NULL) throw (GeometryException)

Set the Position given geodetic coordinates; system is set to Geodetic.

Position & setGeocentric (const double lat, const double lon, const double rad) throw (GeometryException)

Set the Position given geocentric coordinates; system is set to Geocentric.

Position & setSpherical (const double theta, const double phi, const double rad) throw (GeometryException)

Set the Position given spherical coordinates; system is set to Spherical.

Position & setECEF (const double X, const double Y, const double Z) throw ()

Set the Position given ECEF coordinates; system is set to Cartesian.

Position & setECEF (const double XYZ[3]) throw ()

Set the Position given an array of ECEF coordinates; system is set to Cartesian.

Position & setECEF (const Triple &XYZ) throw ()

Set the Position given ECEF coordinates; system is set to Cartesian.

Position & setToString (const std::string &str, const std::string &fmt) throw (GeometryException, DayTime::FormatException, StringUtils::StringException)

setToString, similar to scanf, this function takes a string and a format describing string in order to define Position values.

std::string printf (const char *fmt) const throw (StringUtils::StringException)

Format this Position into a string.

std::string printf (const std::string &fmt) const throw (StringUtils::StringException)

Format this time into a string.

std::string asString () const throw (StringUtils::StringException)

Returns the string that operator<<() would print.

double radiusEarth () const throw ()

A member function that calls the non-member radiusEarth() for this Position.

double elevation (const Position &Target) const throw (GeometryException)

A member function that computes the elevation of the input (Target) position as seen from this Position.

double elevationGeodetic (const Position &Target) const throw (GeometryException)

A member function that computes the elevation of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.

double azimuth (const Position &Target) const throw (GeometryException)

A member function that computes the azimuth of the input (Target) position as seen from this Position.

double azimuthGeodetic (const Position &Target) const throw (GeometryException)

A member function that computes the azimuth of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.

Position getIonosphericPiercePoint (const double elev, const double azim, const double ionoht) const throw ()

A member function that computes the position at which a signal, which is received at this Position and there is observed at the (input) azimuth and elevation angles, crosses a model ionosphere that is taken to be a thin shell at constant (input) height.

Static Public Member Functions

double setPositionTolerance (const double tol)

Changes the POSITION_TOLERANCE for all Position objects.

double getPositionTolerance ()

Returns the current POSITION_TOLERANCE.

void convertSphericalToCartesian (const Triple &tpr, Triple &xyz) throw ()

Fundamental conversion from spherical to cartesian coordinates.

void convertCartesianToSpherical (const Triple &xyz, Triple &tpr) throw ()

Fundamental routine to convert cartesian to spherical coordinates.

void convertCartesianToGeodetic (const Triple &xyz, Triple &llh, const double A, const double eccSq) throw ()

Fundamental routine to convert ECEF (cartesian) to geodetic coordinates, (Geoid specified by semi-major axis and eccentricity squared).

void convertGeodeticToCartesian (const Triple &llh, Triple &xyz, const double A, const double eccSq) throw ()

Fundamental routine to convert geodetic to ECEF (cartesian) coordinates, (Geoid specified by semi-major axis and eccentricity squared).

void convertCartesianToGeocentric (const Triple &xyz, Triple &llr) throw ()

Fundamental routine to convert cartesian (ECEF) to geocentric The zero vector is converted to (0,0,0).

void convertGeocentricToCartesian (const Triple &llr, Triple &xyz) throw ()

Fundamental routine to convert geocentric to cartesian (ECEF).

void convertGeocentricToGeodetic (const Triple &llr, Triple &geodeticllh, const double A, const double eccSq) throw ()

Fundamental routine to convert geocentric to geodetic.

void convertGeodeticToGeocentric (const Triple &geodeticllh, Triple &llr, const double A, const double eccSq) throw ()

Fundamental routine to convert geodetic to geocentric.

double radiusEarth (const double geolat, const double A, const double eccSq) throw ()

Compute the radius of the ellipsoidal Earth, given the geodetic latitude.

Static Public Attributes

const double ONE_MM_TOLERANCE = 0.001

One millimeter tolerance.

const double ONE_CM_TOLERANCE = 0.01

One centimeter tolerance.

const double ONE_UM_TOLERANCE = 0.000001

One micron tolerance.

double POSITION_TOLERANCE = Position::ONE_MM_TOLERANCE

Default tolerance for time equality in days.

Friends

Position operator- (const Position &left, const Position &right) throw ()

Difference two Positions, returning result as a Position in Cartesian coordinates, the only system in which a position difference makes sense.

Position operator+ (const Position &left, const Position &right) throw ()

Add two Positions, returning result as a Position in Cartesian coordinates, the only system in which a position sum makes sense.

Position operator * (const double &scale, const Position &right)

Multiply a Position by a double scalar on the left.

Position operator * (const Position &left, const double &scale)

Multiply a Position by a double scalar on the right.

Position operator * (const int &scale, const Position &right)

Multiply a Position by an integer scalar on the left.

Position operator * (const Position &left, const int &scale)

Multiply a Position by an integer scalar on the right.

std::ostream & operator<< (std::ostream &s, const Position &p)

Stream output for Position objects.

double range (const Position &A, const Position &B) throw (GeometryException)

Compute the range in meters between two Positions.

Member Enumeration Documentation

enum CoordinateSystem

The coordinate systems supported by Position.

Enumeration values:

Unknown unknown coordinate system

Geodetic geodetic latitude, longitude, and height above geoid

Geocentric geocentric (regular spherical coordinates)

Cartesian cartesian (Earth-centered, Earth-fixed)

Spherical spherical coordinates (theta,phi,radius)

Definition at line 124 of file Position.hpp.

Constructor & Destructor Documentation

Position ( ) throw ()

Default constructor.
Initializes to zero, Unknown coordinates
Definition at line 87 of file Position.cpp.
References Position::Unknown.

Position ( const double & a,

const double & b,

const double & c,

CoordinateSystem s = Cartesian,

GeoidModel * geoid = NULL

) throw (GeometryException)

Explicit constructor.
Coordinate system may be specified on input, but defaults to Cartesian. Pointer to GeoidModel may be specified, but default is NULL (in which case WGS84 values will be used).
Parameters:

a first coordinate [ X(m), or latitude (degrees N) ]

b second coordinate [ Y(m), or longitude (degrees E) ]

c third coordinate [ Z, height above ellipsoid or radius, in m ]

s coordinate system

geoid pointer to GeoidModel

Exceptions:

GeometryException on invalid input.

Definition at line 94 of file Position.cpp.
References gpstk::ge(), and GPSTK_RETHROW.

Position ( const double ABC[3],

CoordinateSystem s = Cartesian,

GeoidModel * geoid = NULL

) throw (GeometryException)

Explicit constructor.
Coordinate system may be specified on input, but defaults to Cartesian. Pointer to GeoidModel may be specified, but default is NULL (in which case WGS84 values will be used).
Parameters:

ABC double array[3] coordinate values

s CoordinateSystem

geoid pointer to GeoidModel

Exceptions:

GeometryException on invalid input.

Definition at line 109 of file Position.cpp.
References gpstk::ge(), and GPSTK_RETHROW.

Position ( const Triple & ABC,

CoordinateSystem s = Cartesian,

GeoidModel * geoid = NULL

) throw (GeometryException)

Explicit constructor.
Coordinate system may be specified on input, but defaults to Cartesian. Pointer to GeoidModel may be specified, but default is NULL (in which case WGS84 values will be used).
Parameters:

ABC coordinate values

s CoordinateSystem

geoid pointer to GeoidModel

Exceptions:

GeometryException on invalid input.

Definition at line 125 of file Position.cpp.
References gpstk::ge(), and GPSTK_RETHROW.

Position ( const Xvt & xvt ) throw ()

Explicit constructor from Xvt.
The coordinate system is Cartesian, and the velocity and time information in the input is ignored.
Parameters:

xvt Input Xvt object, xvt.x contains the Cartesian coordinates

Definition at line 141 of file Position.cpp.

~Position ( ) throw () [inline]

Destructor.

Definition at line 231 of file Position.hpp.

Member Function Documentation

Position asECEF ( ) throw () [inline]

Convert to cartesian coordinates (does nothing if system == Cartesian already).

Definition at line 367 of file Position.hpp.

Position asGeodetic ( GeoidModel * geoid ) throw (GeometryException) [inline]

Convert to another geoid, then to geodetic coordinates.

Returns:
a reference to this.

Exceptions:

GeometryException if input is NULL.

Definition at line 356 of file Position.hpp.
References gpstk::ge(), and GPSTK_RETHROW.

Position asGeodetic ( ) throw () [inline]

Convert to geodetic coordinates (does nothing if system == Geodetic already).

Definition at line 349 of file Position.hpp.

string asString ( ) const throw (StringUtils::StringException)

Returns the string that operator<<() would print.

Definition at line 1016 of file Position.cpp.

double azimuth ( const Position & Target ) const throw (GeometryException)

A member function that computes the azimuth of the input (Target) position as seen from this Position.

Parameters:

Target the Position which is observed to have the computed azimuth, as seen from this Position.

Returns:
the azimuth in degrees

Definition at line 1352 of file Position.cpp.
References Triple::azAngle(), gpstk::ge(), GPSTK_RETHROW, and Position::transformTo().
Referenced by main().

double azimuthGeodetic ( const Position & Target ) const throw (GeometryException)

A member function that computes the azimuth of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.

Parameters:

Target the Position which is observed to have the computed azimuth, as seen from this Position.

Returns:
the azimuth in degrees

Definition at line 1379 of file Position.cpp.
References gpstk::cos(), Triple::dot(), gpstk::ge(), Position::getGeodeticLatitude(), Position::getLongitude(), GPSTK_THROW, Triple::mag(), gpstk::sin(), Triple::theArray, and Position::transformTo().

void convertCartesianToGeocentric ( const Triple & xyz,

Triple & llr

) throw () [static]

Fundamental routine to convert cartesian (ECEF) to geocentric The zero vector is converted to (0,0,0).

Parameters:

xyz (input): X,Y,Z

llr (output): geocentric lat(deg N), lon(deg E), radius (units of input)

Definition at line 1131 of file Position.cpp.

void convertCartesianToGeodetic ( const Triple & xyz,

Triple & llh,

const double A,

const double eccSq

) throw () [static]

Fundamental routine to convert ECEF (cartesian) to geodetic coordinates, (Geoid specified by semi-major axis and eccentricity squared).
The zero vector is converted to (90,0,-R(earth)).
Parameters:

xyz (input): X,Y,Z in meters

llh (output): geodetic lat(deg N), lon(deg E), height above ellipsoid (meters)

A (input) Earth semi-major axis

eccSq (input) square of Earth eccentricity Algorithm references: Leick, "GPS Satellite Surveying," 2nd edition.

Definition at line 1075 of file Position.cpp.
References gpstk::cos(), gpstk::sin(), and SQRT.

void convertCartesianToSpherical ( const Triple & xyz,

Triple & tpr

) throw () [static]

Fundamental routine to convert cartesian to spherical coordinates.
The zero vector is converted to (90,0,0).
Parameters:

xyz (input): X,Y,Z

trp (output): theta, phi (degrees), radius (units of input) Algorithm references: standard geometry.

Definition at line 1044 of file Position.cpp.
References gpstk::acos(), and gpstk::RSS().

void convertGeocentricToCartesian ( const Triple & llr,

Triple & xyz

) throw () [static]

Fundamental routine to convert geocentric to cartesian (ECEF).

Parameters:

llr (input): geocentric lat(deg N),lon(deg E),radius

xyz (output): X,Y,Z (units of radius)

Definition at line 1142 of file Position.cpp.

void convertGeocentricToGeodetic ( const Triple & llr,

Triple & geodeticllh,

const double A,

const double eccSq

) throw () [static]

Fundamental routine to convert geocentric to geodetic.

Parameters:

llr (input): geocentric lat(deg N),lon(deg E),radius (meters)

geodeticllh (output): geodetic latitude (deg N), longitude (deg E), and height above ellipsoid (meters)

A (input) Earth semi-major axis

eccSq (input) square of Earth eccentricity

Definition at line 1157 of file Position.cpp.
References gpstk::cos(), gpstk::sin(), and SQRT.

void convertGeodeticToCartesian ( const Triple & llh,

Triple & xyz,

const double A,

const double eccSq

) throw () [static]

Fundamental routine to convert geodetic to ECEF (cartesian) coordinates, (Geoid specified by semi-major axis and eccentricity squared).

Parameters:

llh (input): geodetic lat(deg N), lon(deg E), height above ellipsoid (meters)

A (input) Earth semi-major axis

xyz (output): X,Y,Z in meters

eccSq (input) square of Earth eccentricity Algorithm references: Leick, "GPS Satellite Surveying," 2nd edition.

Definition at line 1113 of file Position.cpp.
References gpstk::cos(), gpstk::sin(), and SQRT.

void convertGeodeticToGeocentric ( const Triple & geodeticllh,

Triple & llr,

const double A,

const double eccSq

) throw () [static]

Fundamental routine to convert geodetic to geocentric.

Parameters:

geodeticllh (input): geodetic latitude (deg N), longitude (deg E), and height above ellipsoid (meters)

llr (output): geocentric lat (deg N),lon (deg E),radius (meters)

A (input) Earth semi-major axis

eccSq (input) square of Earth eccentricity

Definition at line 1202 of file Position.cpp.
References gpstk::acos(), gpstk::sin(), and SQRT.

void convertSphericalToCartesian ( const Triple & tpr,

Triple & xyz

) throw () [static]

Fundamental conversion from spherical to cartesian coordinates.

Parameters:

trp (input): theta, phi (degrees), radius

xyz (output): X,Y,Z in units of radius Algorithm references: standard geometry.

Definition at line 1030 of file Position.cpp.
References gpstk::cos(), and gpstk::sin().

double elevation ( const Position & Target ) const throw (GeometryException)

A member function that computes the elevation of the input (Target) position as seen from this Position.

Parameters:

Target the Position which is observed to have the computed elevation, as seen from this Position.

Returns:
the elevation in degrees

Definition at line 1293 of file Position.cpp.
References Triple::elvAngle(), gpstk::ge(), GPSTK_RETHROW, and Position::transformTo().
Referenced by main().

double elevationGeodetic ( const Position & Target ) const throw (GeometryException)

A member function that computes the elevation of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.

Parameters:

Target the Position which is observed to have the computed elevation, as seen from this Position.

Returns:
the elevation in degrees

Definition at line 1317 of file Position.cpp.
References gpstk::cos(), Triple::dot(), gpstk::ge(), Position::getGeodeticLatitude(), Position::getLongitude(), GPSTK_THROW, Triple::mag(), gpstk::sin(), Triple::theArray, and Position::transformTo().

double geocentricLatitude ( ) const throw ()

return geocentric latitude (degrees North); equal to 90 degress - theta in regular spherical coordinates.

Definition at line 385 of file Position.cpp.
References Position::Geocentric, Triple::theArray, and Position::transformTo().

double geodeticLatitude ( ) const throw ()

return geodetic latitude (degrees North).

Definition at line 373 of file Position.cpp.
References Triple::theArray, and Position::transformTo().

double getAltitude ( ) const throw () [inline]

return height above ellipsoid (meters)

Definition at line 440 of file Position.hpp.
Referenced by MOPSTropModel::MOPSTropModel(), and NeillTropModel::NeillTropModel().

CoordinateSystem getCoordinateSystem ( ) const throw () [inline]

return the coordinate system for this Position

Definition at line 420 of file Position.hpp.

double getGeocentricLatitude ( ) const throw () [inline]

return geocentric latitude (deg N)

Definition at line 430 of file Position.hpp.

double getGeodeticLatitude ( ) const throw () [inline]

return geodetic latitude (deg N)

Definition at line 425 of file Position.hpp.
Referenced by Position::azimuthGeodetic(), Position::elevationGeodetic(), MOPSTropModel::MOPSTropModel(), NeillTropModel::NeillTropModel(), NeillTropModel::setAllParameters(), MOPSTropModel::setAllParameters(), XYZ2NED::XYZ2NED(), and XYZ2NEU::XYZ2NEU().

double getHeight ( void ) const throw () [inline]

return height above ellipsoid (meters)

Definition at line 445 of file Position.hpp.
Referenced by NeillTropModel::setAllParameters(), and MOPSTropModel::setAllParameters().

Position getIonosphericPiercePoint ( const double elev,

const double azim,

const double ionoht

) const throw ()

A member function that computes the position at which a signal, which is received at this Position and there is observed at the (input) azimuth and elevation angles, crosses a model ionosphere that is taken to be a thin shell at constant (input) height.
This function will not transform this Position, and it will return a Position in the same system; the algorithm itself is done in the geocentric coordinate system.
Parameters:

elev elevation angle in degrees of the signal at reception

azim azimuth angle in degrees of the signal at reception

ionoht height of the ionosphere, in meters

Returns:
Position IPP the position of the ionospheric pierce point, in the same coordinate system as *this; *this is not modified.

Definition at line 1439 of file Position.cpp.
References gpstk::asin(), gpstk::cos(), PI, gpstk::sin(), Triple::theArray, and Position::transformTo().
Referenced by main().

double getLongitude ( ) const throw () [inline]

return longitude (deg E) (either geocentric or geodetic)

Definition at line 435 of file Position.hpp.
Referenced by Position::azimuthGeodetic(), Position::elevationGeodetic(), XYZ2NED::XYZ2NED(), and XYZ2NEU::XYZ2NEU().

double getPhi ( ) const throw () [inline]

return spherical coordinate angle phi (deg) (same as longitude)

Definition at line 470 of file Position.hpp.

double getPositionTolerance ( ) [inline, static]

Returns the current POSITION_TOLERANCE.

Definition at line 154 of file Position.hpp.

double getRadius ( ) const throw () [inline]

return radius

Definition at line 475 of file Position.hpp.

string getSystemName ( ) throw ()

return string giving name of coordinate system

Definition at line 58 of file Position.cpp.
Referenced by main().

double getTheta ( ) const throw () [inline]

return spherical coordinate angle theta (deg) (90 - geocentric latitude)

Definition at line 465 of file Position.hpp.

double getX ( ) const throw () [inline]

return ECEF X coordinate (meters)

Definition at line 450 of file Position.hpp.

double getY ( ) const throw () [inline]

return ECEF Y coordinate (meters)

Definition at line 455 of file Position.hpp.

double getZ ( ) const throw () [inline]

return ECEF Z coordinate (meters)

Definition at line 460 of file Position.hpp.

double height ( ) const throw ()

return height above ellipsoid (meters) (Geodetic).

Definition at line 442 of file Position.cpp.
References Triple::theArray, and Position::transformTo().

double longitude ( ) const throw ()

return longitude (degrees East); equal to phi in regular spherical coordinates.

Definition at line 419 of file Position.cpp.
References Position::Spherical, Triple::theArray, and Position::transformTo().

bool operator!= ( const Position & right ) const throw ()

Inequality operator.
Return true if range between this Position and the input Position is greater than tolerance. Return true if geoid values differ.
Parameters:

right Position to be compared to this Position

Definition at line 229 of file Position.cpp.
References gpstk::operator==().

Position & operator+= ( const Position & right ) throw ()

Add a Position to this Position.
Perform the addition in Cartesian coordinates, but return this Position to the system it had originally.
Parameters:

right Position to add to this one.

Returns:
new Position, in the original system.

Definition at line 169 of file Position.cpp.
References Triple::theArray, and Position::transformTo().

Position & operator-= ( const Position & right ) throw ()

Subtract a Position from this Position.
Perform the subtraction in Cartesian coordinates, but return this Position to the system it had originally.
Parameters:

right Position to subtract from this one.

Returns:
new Position, in the original system.

Definition at line 152 of file Position.cpp.
References Triple::theArray, and Position::transformTo().

bool operator== ( const Position & right ) const throw ()

Equality operator.
Return true if range between this Position and the input Position is less than tolerance. Return false if geoid values differ.
Parameters:

right Position to be compared to this Position

Definition at line 217 of file Position.cpp.
References gpstk::range().

double phi ( ) const throw ()

return spherical coordinate phi in degrees

Definition at line 407 of file Position.cpp.
References Position::Spherical, Triple::theArray, and Position::transformTo().

std::string printf ( const std::string & fmt ) const throw (StringUtils::StringException) [inline]

Format this time into a string.

See also:
printf(const char*)

Definition at line 658 of file Position.hpp.

std::string printf ( const char * fmt ) const throw (StringUtils::StringException)

Format this Position into a string.
Generate and return a string containing formatted Position coordinates, formatted by the specification fmt.

%x X() (meters)

%y Y() (meters)

%z Z() (meters)

%X X()/1000 (kilometers)

%Y Y()/1000 (kilometers)

%Z Z()/1000 (kilometers)

%A


Public Types
enum	CoordinateSystem { Unknown = 0, Geodetic, Geocentric, Cartesian, Spherical }
	The coordinate systems supported by Position. More...
Public Member Functions
std::string	getSystemName () throw ()
	return string giving name of coordinate system
Position &	setTolerance (const double tol) throw ()
	Sets the tolerance for output and comparisons, for this object only.
	Position () throw ()
	Default constructor.
	Position (const double &a, const double &b, const double &c, CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)
	Explicit constructor.
	Position (const double ABC[3], CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)
	Explicit constructor.
	Position (const Triple &ABC, CoordinateSystem s=Cartesian, GeoidModel *geoid=NULL) throw (GeometryException)
	Explicit constructor.
	Position (const Xvt &xvt) throw ()
	Explicit constructor from Xvt.
	~Position () throw ()
	Destructor.
Position &	operator-= (const Position &right) throw ()
	Subtract a Position from this Position.
Position &	operator+= (const Position &right) throw ()
	Add a Position to this Position.
bool	operator== (const Position &right) const throw ()
	Equality operator.
bool	operator!= (const Position &right) const throw ()
	Inequality operator.
Position	transformTo (CoordinateSystem sys) throw ()
	Transform coordinate system.
Position	asGeodetic () throw ()
	Convert to geodetic coordinates (does nothing if system == Geodetic already).
Position	asGeodetic (GeoidModel *geoid) throw (GeometryException)
	Convert to another geoid, then to geodetic coordinates.
Position	asECEF () throw ()
	Convert to cartesian coordinates (does nothing if system == Cartesian already).
double	X () const throw ()
	return X coordinate (meters)
double	Y () const throw ()
	return Y coordinate (meters)
double	Z () const throw ()
	return Z coordinate (meters)
double	geodeticLatitude () const throw ()
	return geodetic latitude (degrees North).
double	geocentricLatitude () const throw ()
	return geocentric latitude (degrees North); equal to 90 degress - theta in regular spherical coordinates.
double	theta () const throw ()
	return spherical coordinate theta in degrees
double	phi () const throw ()
	return spherical coordinate phi in degrees
double	longitude () const throw ()
	return longitude (degrees East); equal to phi in regular spherical coordinates.
double	radius () const throw ()
	return distance from the center of Earth (meters), Same as radius in spherical coordinates.
double	height () const throw ()
	return height above ellipsoid (meters) (Geodetic).
CoordinateSystem	getCoordinateSystem () const throw ()
	return the coordinate system for this Position
double	getGeodeticLatitude () const throw ()
	return geodetic latitude (deg N)
double	getGeocentricLatitude () const throw ()
	return geocentric latitude (deg N)
double	getLongitude () const throw ()
	return longitude (deg E) (either geocentric or geodetic)
double	getAltitude () const throw ()
	return height above ellipsoid (meters)
double	getHeight () const throw ()
	return height above ellipsoid (meters)
double	getX () const throw ()
	return ECEF X coordinate (meters)
double	getY () const throw ()
	return ECEF Y coordinate (meters)
double	getZ () const throw ()
	return ECEF Z coordinate (meters)
double	getTheta () const throw ()
	return spherical coordinate angle theta (deg) (90 - geocentric latitude)
double	getPhi () const throw ()
	return spherical coordinate angle phi (deg) (same as longitude)
double	getRadius () const throw ()
	return radius
void	setGeoidModel (const GeoidModel *geoid) throw (GeometryException)
	Set the geoid values for this Position given a geoid.
Position &	setGeodetic (const double lat, const double lon, const double ht, const GeoidModel *geoid=NULL) throw (GeometryException)
	Set the Position given geodetic coordinates; system is set to Geodetic.
Position &	setGeocentric (const double lat, const double lon, const double rad) throw (GeometryException)
	Set the Position given geocentric coordinates; system is set to Geocentric.
Position &	setSpherical (const double theta, const double phi, const double rad) throw (GeometryException)
	Set the Position given spherical coordinates; system is set to Spherical.
Position &	setECEF (const double X, const double Y, const double Z) throw ()
	Set the Position given ECEF coordinates; system is set to Cartesian.
Position &	setECEF (const double XYZ[3]) throw ()
	Set the Position given an array of ECEF coordinates; system is set to Cartesian.
Position &	setECEF (const Triple &XYZ) throw ()
	Set the Position given ECEF coordinates; system is set to Cartesian.
Position &	setToString (const std::string &str, const std::string &fmt) throw (GeometryException, DayTime::FormatException, StringUtils::StringException)
	setToString, similar to scanf, this function takes a string and a format describing string in order to define Position values.
std::string	printf (const char *fmt) const throw (StringUtils::StringException)
	Format this Position into a string.
std::string	printf (const std::string &fmt) const throw (StringUtils::StringException)
	Format this time into a string.
std::string	asString () const throw (StringUtils::StringException)
	Returns the string that operator<<() would print.
double	radiusEarth () const throw ()
	A member function that calls the non-member radiusEarth() for this Position.
double	elevation (const Position &Target) const throw (GeometryException)
	A member function that computes the elevation of the input (Target) position as seen from this Position.
double	elevationGeodetic (const Position &Target) const throw (GeometryException)
	A member function that computes the elevation of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.
double	azimuth (const Position &Target) const throw (GeometryException)
	A member function that computes the azimuth of the input (Target) position as seen from this Position.
double	azimuthGeodetic (const Position &Target) const throw (GeometryException)
	A member function that computes the azimuth of the input (Target) position as seen from this Position, using a Geodetic (ellipsoidal) system.
Position	getIonosphericPiercePoint (const double elev, const double azim, const double ionoht) const throw ()
	A member function that computes the position at which a signal, which is received at this Position and there is observed at the (input) azimuth and elevation angles, crosses a model ionosphere that is taken to be a thin shell at constant (input) height.
Static Public Member Functions
double	setPositionTolerance (const double tol)
	Changes the POSITION_TOLERANCE for all Position objects.
double	getPositionTolerance ()
	Returns the current POSITION_TOLERANCE.
void	convertSphericalToCartesian (const Triple &tpr, Triple &xyz) throw ()
	Fundamental conversion from spherical to cartesian coordinates.
void	convertCartesianToSpherical (const Triple &xyz, Triple &tpr) throw ()
	Fundamental routine to convert cartesian to spherical coordinates.
void	convertCartesianToGeodetic (const Triple &xyz, Triple &llh, const double A, const double eccSq) throw ()
	Fundamental routine to convert ECEF (cartesian) to geodetic coordinates, (Geoid specified by semi-major axis and eccentricity squared).
void	convertGeodeticToCartesian (const Triple &llh, Triple &xyz, const double A, const double eccSq) throw ()
	Fundamental routine to convert geodetic to ECEF (cartesian) coordinates, (Geoid specified by semi-major axis and eccentricity squared).
void	convertCartesianToGeocentric (const Triple &xyz, Triple &llr) throw ()
	Fundamental routine to convert cartesian (ECEF) to geocentric The zero vector is converted to (0,0,0).
void	convertGeocentricToCartesian (const Triple &llr, Triple &xyz) throw ()
	Fundamental routine to convert geocentric to cartesian (ECEF).
void	convertGeocentricToGeodetic (const Triple &llr, Triple &geodeticllh, const double A, const double eccSq) throw ()
	Fundamental routine to convert geocentric to geodetic.
void	convertGeodeticToGeocentric (const Triple &geodeticllh, Triple &llr, const double A, const double eccSq) throw ()
	Fundamental routine to convert geodetic to geocentric.
double	radiusEarth (const double geolat, const double A, const double eccSq) throw ()
	Compute the radius of the ellipsoidal Earth, given the geodetic latitude.
Static Public Attributes
const double	ONE_MM_TOLERANCE = 0.001
	One millimeter tolerance.
const double	ONE_CM_TOLERANCE = 0.01
	One centimeter tolerance.
const double	ONE_UM_TOLERANCE = 0.000001
	One micron tolerance.
double	POSITION_TOLERANCE = Position::ONE_MM_TOLERANCE
	Default tolerance for time equality in days.
Friends
Position	operator- (const Position &left, const Position &right) throw ()
	Difference two Positions, returning result as a Position in Cartesian coordinates, the only system in which a position difference makes sense.
Position	operator+ (const Position &left, const Position &right) throw ()
	Add two Positions, returning result as a Position in Cartesian coordinates, the only system in which a position sum makes sense.
Position	operator * (const double &scale, const Position &right)
	Multiply a Position by a double scalar on the left.
Position	operator * (const Position &left, const double &scale)
	Multiply a Position by a double scalar on the right.
Position	operator * (const int &scale, const Position &right)
	Multiply a Position by an integer scalar on the left.
Position	operator * (const Position &left, const int &scale)
	Multiply a Position by an integer scalar on the right.
std::ostream &	operator<< (std::ostream &s, const Position &p)
	Stream output for Position objects.
double	range (const Position &A, const Position &B) throw (GeometryException)
	Compute the range in meters between two Positions.

Position Class Reference [Geodetic coordinates and geoids]

Detailed Description

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Position Class Reference
[Geodetic coordinates and geoids]