isce3::core::Ellipsoid Class Reference

Data structure to store Ellipsoid information. More...

#include <Ellipsoid.h>

Public Member Functions
CUDA_HOSTDEV	Ellipsoid (double maj, double ecc)
	Constructor using semi-major axis and eccentricity^2.
CUDA_HOSTDEV double	a () const
	Return semi-major axis.
CUDA_HOSTDEV double	b () const
	Return semi-minor axis.
CUDA_HOSTDEV double	e2 () const
	Return eccentricity^2.
void	a (double val)
	Set semi-major axis.
void	e2 (double val)
	Set eccentricity^2.
CUDA_HOSTDEV double	rEast (double lat) const
	Return local radius in EW direction.
CUDA_HOSTDEV double	rNorth (double lat) const
	Return local radius in NS direction.
CUDA_HOSTDEV double	rDir (double hdg, double lat) const
	Return directional local radius.
CUDA_HOSTDEV void	lonLatToXyz (const cartesian_t &llh, cartesian_t &xyz) const
	Transform WGS84 Lon/Lat/Hgt to ECEF xyz.
CUDA_HOSTDEV Vec3	lonLatToXyz (const Vec3 &llh) const
CUDA_HOSTDEV void	xyzToLonLat (const cartesian_t &xyz, cartesian_t &llh) const
	Transform ECEF xyz to Lon/Lat/Hgt.
CUDA_HOSTDEV Vec3	xyzToLonLat (const Vec3 &xyz) const
CUDA_HOSTDEV void	nVector (double lon, double lat, cartesian_t &vec) const
	Return normal to the ellipsoid at given lon, lat.
CUDA_HOSTDEV Vec3	nVector (double lon, double lat) const
CUDA_HOSTDEV void	xyzOnEllipse (double lon, double lat, cartesian_t &xyz) const
	Return ECEF coordinates of point on ellipse.
void	getImagingAnglesAtPlatform (const cartesian_t &pos, const cartesian_t &vel, const cartesian_t &los, double &azi, double &look) const
	Estimate azimuth angle and look angle for a given LOS vector.

Detailed Description

Data structure to store Ellipsoid information.

Only the semi-major axis and the eccentricity^2 parameters are stored. All other quantities are derived on the fly

Constructor & Destructor Documentation

Ellipsoid()

CUDA_HOSTDEV isce3::core::Ellipsoid::Ellipsoid ( double maj, double ecc )

inline

Constructor using semi-major axis and eccentricity^2.

Parameters

[in]	maj	Semi-major of axis in meters
[in]	ecc	Square of ellipsoid eccentricity (unitless)

Member Function Documentation

a()

void isce3::core::Ellipsoid::a ( double val )

inline

Set semi-major axis.

Parameters

[in]

val

Semi-major axis of ellipsoid in meters

b()

CUDA_HOSTDEV double isce3::core::Ellipsoid::b ( ) const

inline

Return semi-minor axis.

Computed from a and e2.

e2()

void isce3::core::Ellipsoid::e2 ( double val )

inline

Set eccentricity^2.

Parameters

[in]

ecc

Eccentricity-squared of ellipsoid

getImagingAnglesAtPlatform()

void isce3::core::Ellipsoid::getImagingAnglesAtPlatform	(	const cartesian_t &	pos,
		const cartesian_t &	vel,
		const cartesian_t &	los,
		double &	azi,
		double &	look ) const

Estimate azimuth angle and look angle for a given LOS vector.

Parameters

[in]	pos	ECEF coordinates of imaging platform in meters
[in]	vel	ECEF velocity of imaging platform in meters / sec
[in]	los	Line-of-sight (LOS) vector in ECEF coordinates (meters), pointing from platform to target
[out]	azi	Azimuth angle in radians
[out]	look	Look angle in radians

Azimuth angle is defined as angle of the LOS vector from the North Direction in the anti-clockwise direction. Look angle is defined as angle of the LOS vector and the downward normal at the imaging platform .

lonLatToXyz()

CUDA_HOSTDEV void isce3::core::Ellipsoid::lonLatToXyz ( const cartesian_t & llh, cartesian_t & xyz ) const

inline

Transform WGS84 Lon/Lat/Hgt to ECEF xyz.

Parameters

[in]	llh	Latitude (ras), Longitude (rad), Height (m).
[out]	xyz	ECEF Cartesian coordinates in meters.

nVector()

CUDA_HOSTDEV void isce3::core::Ellipsoid::nVector ( double lon, double lat, cartesian_t & vec ) const

inline

Return normal to the ellipsoid at given lon, lat.

Parameters

[in]	lon	Longitude in radians
[in]	lat	Latitude in radians
[out]	vec	Unit vector of normal pointing outwards in ECEF cartesian coordinates

See N-vector

rDir()

CUDA_HOSTDEV double isce3::core::Ellipsoid::rDir ( double hdg, double lat ) const

inline

Return directional local radius.

Parameters

[in]	hdg	Heading in radians
[in]	lat	Latitude in radians

Heading is measured in clockwise direction from the North direction. See Directional Radius

rEast()

CUDA_HOSTDEV double isce3::core::Ellipsoid::rEast ( double lat ) const

inline

Return local radius in EW direction.

Parameters

[in]

lat

Latitude in radians

See Prime vertical radius

rNorth()

CUDA_HOSTDEV double isce3::core::Ellipsoid::rNorth ( double lat ) const

inline

Return local radius in NS direction.

Parameters

[in]

lat

Latitude in radians

See Meridional radius

xyzOnEllipse()

CUDA_HOSTDEV void isce3::core::Ellipsoid::xyzOnEllipse ( double lon, double lat, cartesian_t & vec ) const

inline

Return ECEF coordinates of point on ellipse.

Parameters

[in]	lon	Longitude in radians
[in]	lat	Latitude in radians
[out]	xyz	ECEF coordinates of point on ellipse

See parametric representation of ellipsoid

xyzToLonLat()

CUDA_HOSTDEV void isce3::core::Ellipsoid::xyzToLonLat ( const cartesian_t & xyz, cartesian_t & llh ) const

inline

Transform ECEF xyz to Lon/Lat/Hgt.

Parameters

[in]	xyz	ECEF Cartesian coordinates in meters.
[out]	llh	Latitude (rad), Longitude(rad), Height (m).

Using the approach laid out in Vermeille, 2002 [vermeille2002direct]

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

• /home/runner/work/isce3/isce3/cxx/isce3/core/Ellipsoid.h
• /home/runner/work/isce3/isce3/cxx/isce3/core/Ellipsoid.cpp