#include "geodetic.h"
#include <cmath>
#include <stdexcept>
#include "math_funcs.h"
#include "ppath.h"

Functions
void	cart2pol (Numeric &r, Numeric &lat, const Numeric &x, const Numeric &z, const Numeric &lat0, const Numeric &za0)
	cart2pol More...

void	cart2poslos (Numeric &r, Numeric &lat, Numeric &za, const Numeric &x, const Numeric &z, const Numeric &dx, const Numeric &dz, const Numeric &ppc, const Numeric &lat0, const Numeric &za0)
	cart2poslos More...

void	distance2D (Numeric &l, const Numeric &r1, const Numeric &lat1, const Numeric &r2, const Numeric &lat2)
	distance2D More...

void	line_circle_intersect (Numeric &x, Numeric &z, const Numeric &xl, const Numeric &zl, const Numeric &dx, const Numeric &dz, const Numeric &xc, const Numeric &zc, const Numeric &r)
	geomtanpoint2d More...

void	pol2cart (Numeric &x, Numeric &z, const Numeric &r, const Numeric &lat)
	pol2cart More...

void	poslos2cart (Numeric &x, Numeric &z, Numeric &dx, Numeric &dz, const Numeric &r, const Numeric &lat, const Numeric &za)
	poslos2cart More...

void	cart2poslos (Numeric &r, Numeric &lat, Numeric &lon, Numeric &za, Numeric &aa, const Numeric &x, const Numeric &y, const Numeric &z, const Numeric &dx, const Numeric &dy, const Numeric &dz, const Numeric &ppc, const Numeric &x0, const Numeric &y0, const Numeric &z0, const Numeric &lat0, const Numeric &lon0, const Numeric &za0, const Numeric &aa0)
	cart2poslos More...

void	cart2sph (Numeric &r, Numeric &lat, Numeric &lon, const Numeric &x, const Numeric &y, const Numeric &z, const Numeric &lat0, const Numeric &lon0, const Numeric &za0, const Numeric &aa0)
	cart2sph More...

void	distance3D (Numeric &l, const Numeric &r1, const Numeric &lat1, const Numeric &lon1, const Numeric &r2, const Numeric &lat2, const Numeric &lon2)
	distance3D More...

void	geompath_tanpos_3d (Numeric &r_tan, Numeric &lat_tan, Numeric &lon_tan, Numeric &l_tan, const Numeric &r, const Numeric &lat, const Numeric &lon, const Numeric &za, const Numeric &aa, const Numeric &ppc)
	geompath_tanpos_3d More...

void	line_sphere_intersect (Numeric &x, Numeric &y, Numeric &z, const Numeric &xl, const Numeric &yl, const Numeric &zl, const Numeric &dx, const Numeric &dy, const Numeric &dz, const Numeric &xc, const Numeric &yc, const Numeric &zc, const Numeric &r)
	geomtanpoint More...

void	latlon_at_aa (Numeric &lat2, Numeric &lon2, const Numeric &lat1, const Numeric &lon1, const Numeric &aa, const Numeric &ddeg)
	latlon_at_aa More...

void	los2xyz (Numeric &za, Numeric &aa, const Numeric &r1, const Numeric &lat1, const Numeric &lon1, const Numeric &x1, const Numeric &y1, const Numeric &z1, const Numeric &x2, const Numeric &y2, const Numeric &z2)
	los2xyz More...

void	poslos2cart (Numeric &x, Numeric &y, Numeric &z, Numeric &dx, Numeric &dy, Numeric &dz, const Numeric &r, const Numeric &lat, const Numeric &lon, const Numeric &za, const Numeric &aa)
	poslos2cart More...

Numeric	pos2refell_r (const Index &atmosphere_dim, ConstVectorView refellipsoid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstVectorView rte_pos)
	pos2refell_r More...

Numeric	refell2r (ConstVectorView refellipsoid, const Numeric &lat)
	refell2r More...

Numeric	refell2d (ConstVectorView refellipsoid, ConstVectorView lat_grid, const GridPos gp)
	refell2d More...

Numeric	sphdist (const Numeric &lat1, const Numeric &lon1, const Numeric &lat2, const Numeric &lon2)
	sphdist More...

void	sph2cart (Numeric &x, Numeric &y, Numeric &z, const Numeric &r, const Numeric &lat, const Numeric &lon)
	sph2cart More...

void	lon_shiftgrid (Vector &longrid_out, ConstVectorView longrid_in, const Numeric lon)
	lon_shiftgrid More...

void	cycle_lat_lon (Numeric &lat, Numeric &lon)
	Cyclic latitude longitude coordinates. More...

Variables
const Numeric	DEG2RAD

const Numeric	RAD2DEG

Detailed Description

Author: Patrick Eriksson Patri.nosp@m.ck.E.nosp@m.rikss.nosp@m.on@c.nosp@m.halme.nosp@m.rs.s.nosp@m.e

Date: 2012-02-06

This file contains functions associated with the reference ellipsoid, conversion between latitudes and similar stuff.

Definition in file geodetic.cc.

Function Documentation

◆ cart2pol()

void cart2pol	(	Numeric &	r,
		Numeric &	lat,
		const Numeric &	x,
		const Numeric &	z,
		const Numeric &	lat0,
		const Numeric &	za0
	)

cart2pol

The inverse of pol2cart.

A 2D version of cart2sph

Parameters

r	Out: Radius of position.
lat	Out: Latitude of position.
x	x-coordinate of position.
z	z-coordinate of position.
lat0	Original latitude.
za0	Original zenith angle.

Author: Patrick Eriksson

Date: 2012-03-20

Definition at line 74 of file geodetic.cc.

References abs, ANGTOL, RAD2DEG, and sqrt().

Referenced by defocusing_general_sub(), do_gridcell_2d_byltest(), and ppathFromRtePos2().

◆ cart2poslos() [1/2]

void cart2poslos	(	Numeric &	r,
		Numeric &	lat,
		Numeric &	za,
		const Numeric &	x,
		const Numeric &	z,
		const Numeric &	dx,
		const Numeric &	dz,
		const Numeric &	ppc,
		const Numeric &	lat0,
		const Numeric &	za0
	)

cart2poslos

2D version of the 3D cart2poslos.

Parameters

r	Out: Radius of observation position.
lat	Out: Latitude of observation position.
za	Out: LOS zenith angle at observation position.
x	x-coordinate of observation position.
z	z-coordinate of observation position.
dx	x-part of LOS unit vector.
dz	z-part of LOS unit vector.
ppc	Propagation path constant (r*sin(za))
lat0	Original latitude.
za0	Original zenith angle.

Author: Patrick Eriksson

Date: 2012-03-21

Definition at line 113 of file geodetic.cc.

References abs, ANGTOL, DEG2RAD, RAD2DEG, and sqrt().

Referenced by do_gridcell_2d_byltest(), do_gridcell_3d_byltest(), ppath_start_stepping(), ppathFromRtePos2(), and raytrace_3d_linear_basic().

◆ cart2poslos() [2/2]

void cart2poslos	(	Numeric &	r,
		Numeric &	lat,
		Numeric &	lon,
		Numeric &	za,
		Numeric &	aa,
		const Numeric &	x,
		const Numeric &	y,
		const Numeric &	z,
		const Numeric &	dx,
		const Numeric &	dy,
		const Numeric &	dz,
		const Numeric &	ppc,
		const Numeric &	x0,
		const Numeric &	y0,
		const Numeric &	z0,
		const Numeric &	lat0,
		const Numeric &	lon0,
		const Numeric &	za0,
		const Numeric &	aa0
	)

cart2poslos

The inverse of poslos2cart.

Beside the cartesian coordinates (x,y,z,dx,dy,dz), the function takes as input information about the original position and LOS. The later data are used to improve the accuracy. For example, for zenith and nadir cases it is ensured that the latitude and longitude are not changed. This makes the function slower, but accuarcy is favoured as zenith, nadir, north and south line-of-sights are especially tricky as they can go along a grid box boundary and the smallest rounding error can move the path from one grid box to the neighbouring one.

Parameters

r	Out: Radius of observation position.
lat	Out: Latitude of observation position.
lon	Out: Longitude of observation position.
za	Out: LOS zenith angle at observation position.
aa	Out: LOS azimuth angle at observation position.
x	x-coordinate of observation position.
y	y-coordinate of observation position.
z	z-coordinate of observation position.
dx	x-part of LOS unit vector.
dy	y-part of LOS unit vector.
dz	z-part of LOS unit vector.
ppc	Propagation path constant (r*sin(za))
lat0	Original latitude.
lon0	Original longitude.
za0	Original zenith angle.
aa0	Original azimuth angle.

Author: Patrick Eriksson

Date: 2002-12-30

Definition at line 421 of file geodetic.cc.

References abs, ANGTOL, DEG2RAD, geompath_l_at_r(), POLELAT, pow(), RAD2DEG, and sqrt().

◆ cart2sph()

void cart2sph	(	Numeric &	r,
		Numeric &	lat,
		Numeric &	lon,
		const Numeric &	x,
		const Numeric &	y,
		const Numeric &	z,
		const Numeric &	lat0,
		const Numeric &	lon0,
		const Numeric &	za0,
		const Numeric &	aa0
	)

cart2sph

The inverse of sph2cart.

For definition of lat0, lon0, za0 and aa0, see cart2poslos.

Parameters

r	Out: Radius of observation position.
lat	Out: Latitude of observation position.
lon	Out: Longitude of observation position.
x	x-coordinate of observation position.
y	y-coordinate of observation position.
z	z-coordinate of observation position.
lat0	Original latitude.
lon0	Original longitude.
za0	Original zenith angle.
aa0	Original azimuth angle.

Author: Patrick Eriksson

Date: 2002-12-30

Definition at line 563 of file geodetic.cc.

References abs, ANGTOL, POLELAT, RAD2DEG, and sqrt().

Referenced by defocusing_general_sub(), do_gridcell_3d_byltest(), geompath_tanpos_3d(), and ppathFromRtePos2().

◆ cycle_lat_lon()

void cycle_lat_lon	(	Numeric &	lat,
		Numeric &	lon
	)

Cyclic latitude longitude coordinates.

Definition at line 1300 of file geodetic.cc.

Referenced by TelsemAtlas::calc_cellnum_nearest_neighbor().

◆ distance2D()

void distance2D	(	Numeric &	l,
		const Numeric &	r1,
		const Numeric &	lat1,
		const Numeric &	r2,
		const Numeric &	lat2
	)

distance2D

The distance between two 2D points.

The two latitudes can deviate with max 180 degrees.

Parameters

l	Out: The distance
r1	Radius of position 1
lat1	Latitude of position 1
r2	Radius of position 2
lat2	Latitude of position 2

Author: Patrick Eriksson

Date: 2012-03-20

Definition at line 182 of file geodetic.cc.

References abs, dx, pol2cart(), sqrt(), x1, and x2.

Referenced by defocusing_general(), and ppathFromRtePos2().

◆ distance3D()

void distance3D	(	Numeric &	l,
		const Numeric &	r1,
		const Numeric &	lat1,
		const Numeric &	lon1,
		const Numeric &	r2,
		const Numeric &	lat2,
		const Numeric &	lon2
	)

distance3D

The distance between two 3D points.

Parameters

l	Out: The distance
r1	Radius of position 1
lat1	Latitude of position 1
lon1	Longitude of position 1
r2	Radius of position 2
lat2	Latitude of position 2
lon2	Longitude of position 2

Author: Patrick Eriksson

Date: 2012-03-20

Definition at line 618 of file geodetic.cc.

References dx, sph2cart(), sqrt(), x1, and x2.

Referenced by defocusing_general(), and ppathFromRtePos2().

◆ geompath_tanpos_3d()

void geompath_tanpos_3d	(	Numeric &	r_tan,
		Numeric &	lat_tan,
		Numeric &	lon_tan,
		Numeric &	l_tan,
		const Numeric &	r,
		const Numeric &	lat,
		const Numeric &	lon,
		const Numeric &	za,
		const Numeric &	aa,
		const Numeric &	ppc
	)

geompath_tanpos_3d

Position of the tangent point for 3D cases.

The zenith angle must be >= 90.

Parameters

r_tan	Out: Radius of tangent point.
lat_tan	Out: Latitude of tangent point.
lon_tan	Out: Longitude of tangent point.
l_tan	Out: Distance along path to the tangent point.
r	Radius of observation position.
lat	Latitude of observation position.
lon	Longitude of observation position.
za	LOS zenith angle at observation position.
aa	LOS azimuth angle at observation position.
ppc	Geometrical propagation path constant.

Author: Patrick Eriksson

Date: 2002-12-31

Definition at line 655 of file geodetic.cc.

References cart2sph(), dx, poslos2cart(), and sqrt().

Referenced by do_gridcell_3d().

◆ latlon_at_aa()

void latlon_at_aa	(	Numeric &	lat2,
		Numeric &	lon2,
		const Numeric &	lat1,
		const Numeric &	lon1,
		const Numeric &	aa,
		const Numeric &	ddeg
	)

latlon_at_aa

Destination point given distance and bearing from start point

Calculates the latitude and longitide, given a position, an azimuth angle and an angular distance.

Parameters

lat2	Latitude of end position.
lon2	Longitude of end position.
lat1	Latitude of start position.
lon1	Longitude of start position.
aa	Azimuth/bearing at start point.
ddeg	Angular distance (in degrees).

Author: Patrick Eriksson

Date: 2012-04-23

Definition at line 883 of file geodetic.cc.

References DEG2RAD, and RAD2DEG.

◆ line_circle_intersect()

void line_circle_intersect	(	Numeric &	x,
		Numeric &	z,
		const Numeric &	xl,
		const Numeric &	zl,
		const Numeric &	dx,
		const Numeric &	dz,
		const Numeric &	xc,
		const Numeric &	zc,
		const Numeric &	r
	)

geomtanpoint2d

Position of the tangent point for 3D cases.

Calculates the 3D geometrical tangent point for arbitrary reference ellipsiod. That is, a spherical planet is not assumed. The tangent point is thus defined as the point closest to the ellipsoid (not as the ppoint with za=90).

Geocentric coordinates are used for both sensor and tangent point positions.

The algorithm used for non-spherical cases is derived by Nick Lloyd at University of Saskatchewan, Canada (nick..nosp@m.lloy.nosp@m.d@usa.nosp@m.sk.c.nosp@m.a), and is part of the operational code for both OSIRIS and SMR on-board- the Odin satellite.

The zenith angle must be >= 90.

Parameters

r_tan	Out: Radius of tangent point.
lat_tan	Out: Latitude of tangent point.
lon_tan	Out: Longitude of tangent point.
r	Radius of observation position.
lat	Latitude of observation position.
lon	Longitude of observation position.
za	LOS zenith angle at observation position.
aa	LOS azimuth angle at observation position.

Author: Patrick Eriksson

Date: 2012-02-12line_circle_intersect

Find the intersection between a line and a circle

Parameters

x	Out: X-coordinate of intersection
z	Out: Z-coordinate of intersection
xl	A x-coordinate on the line
zl	A z-coordinate on the line
dx	X-component of line direction vector
dz	Z-component of line direction vector
xc	X-coordinate of sphere origo
zc	Z-coordinate of sphere origo
r	Radius of sphere

Author: Patrick Eriksson

Date: 2012-03-30

Definition at line 278 of file geodetic.cc.

Referenced by ppathFromRtePos2().

◆ line_sphere_intersect()

void line_sphere_intersect	(	Numeric &	x,
		Numeric &	y,
		Numeric &	z,
		const Numeric &	xl,
		const Numeric &	yl,
		const Numeric &	zl,
		const Numeric &	dx,
		const Numeric &	dy,
		const Numeric &	dz,
		const Numeric &	xc,
		const Numeric &	yc,
		const Numeric &	zc,
		const Numeric &	r
	)

geomtanpoint

Position of the tangent point for 3D cases.

Calculates the 3D geometrical tangent point for arbitrary reference ellipsiod. That is, a spherical planet is not assumed. The tangent point is thus defined as the point closest to the ellipsoid (not as the ppoint with za=90).

Geocentric coordinates are used for both sensor and tangent point positions.

The algorithm used for non-spherical cases is derived by Nick Lloyd at University of Saskatchewan, Canada (nick..nosp@m.lloy.nosp@m.d@usa.nosp@m.sk.c.nosp@m.a), and is part of the operational code for both OSIRIS and SMR on-board- the Odin satellite.

The zenith angle must be >= 90.

Parameters

r_tan	Out: Radius of tangent point.
lat_tan	Out: Latitude of tangent point.
lon_tan	Out: Longitude of tangent point.
r	Radius of observation position.
lat	Latitude of observation position.
lon	Longitude of observation position.
za	LOS zenith angle at observation position.
aa	LOS azimuth angle at observation position.

Author: Patrick Eriksson

Date: 2012-02-12line_sphere_intersect

Find the intersection between a line and a sphere

Parameters

x	Out: X-coordinate of intersection
y	Out: Y-coordinate of intersection
z	Out: Z-coordinate of intersection
xl	A x-coordinate on the line
yl	A y-coordinate on the line
zl	A z-coordinate on the line
dx	X-component of line direction vector
dy	Y-component of line direction vector
dz	Z-component of line direction vector
xc	X-coordinate of sphere origo
yc	Y-coordinate of sphere origo
zc	Z-coordinate of sphere origo
r	Radius of sphere

Author: Patrick Eriksson

Date: 2012-03-30

Definition at line 823 of file geodetic.cc.

Referenced by ppathFromRtePos2().

◆ lon_shiftgrid()

void lon_shiftgrid	(	Vector &	longrid_out,
		ConstVectorView	longrid_in,
		const Numeric	lon
	)

lon_shiftgrid

Shifting longitude grid by +/- 360 to the same region as a given longitude.

Longitudes are allowed to be in [-360,360], but only covering at maximum 360 degrees at once. Different variables might be specified in different spaces of the allowed range. lon_shiftgrid shifts the longitude grid to the same space as the lon value. However, no check is done that lon is indeed within the range of longrid_out (only same region).

Parameters

longrid_out	Out: shifted longitude grid.
longrid_in	Original longitude grid.
lon	A longitude value.

Author: Jana Mendrok

Date: 2012-06-28

Definition at line 1276 of file geodetic.cc.

References ConstVectorView::nelem().

Referenced by InterpGriddedField2ToPosition(), surface_complex_refr_indexFromGriddedField5(), surface_reflectivityFromGriddedField6(), surface_scalar_reflectivityFromGriddedField4(), and surface_typeInterpTypeMask().

◆ los2xyz()

void los2xyz	(	Numeric &	za,
		Numeric &	aa,
		const Numeric &	r1,
		const Numeric &	lat1,
		const Numeric &	lon1,
		const Numeric &	x1,
		const Numeric &	y1,
		const Numeric &	z1,
		const Numeric &	x2,
		const Numeric &	y2,
		const Numeric &	z2
	)

los2xyz

Line-of-sight to another position given in cartesian coordinates.

Calculates the zenith and azimuth angle for the geomrical path from position 1 to position 2.

Parameters

za	Out: LOS zenith angle at position 1.
aa	Out: LOS azimuth angle at position 1.
r	Radius of position 1.
lat	Latitude of position 1.
lon	Longitude of position 1.
x1	x-coordinate of position 1.
y1	y-coordinate of position 1.
z1	z-coordinate of position 1.
x2	x-coordinate of position 2.
y2	y-coordinate of position 2.
z2	z-coordinate of position 2.

Author: Patrick Eriksson

Date: 2012-03-26

Definition at line 929 of file geodetic.cc.

References DEG2RAD, dx, RAD2DEG, sqrt(), and x1.

Referenced by rte_losGeometricFromRtePosToRtePos2().

◆ pol2cart()

void pol2cart	(	Numeric &	x,
		Numeric &	z,
		const Numeric &	r,
		const Numeric &	lat
	)

pol2cart

Conversion from polar to cartesian coordinates.

The cartesian coordinate system is defined such as the x-axis goes along lat=0 and lon=0 and z-axis goes along lat=90.

Parameters

x	Out: x position.
z	Out: z position.
r	Radius.
lat	Latitude.

Author: Patrick Eriksson

Date: 2012-03-20

Definition at line 331 of file geodetic.cc.

References DEG2RAD.

Referenced by distance2D(), ppathFromRtePos2(), and rte_losGeometricFromRtePosToRtePos2().

◆ pos2refell_r()

Numeric pos2refell_r	(	const Index &	atmosphere_dim,
		ConstVectorView	refellipsoid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstVectorView	rte_pos
	)

pos2refell_r

Extracts the reference ellipsoid for the specified position.

The reference ellipsoid radius is defined slightly differently inside and outside of the model atmosphere. See refell2r. This function takes care of all those aspects.

If you know the latitude grid position of rte_pos, it is faster to use refell2d*.

Returns: Ellispoid radius

Parameters

atmosphere_dim	In: As the WSV with same name.
refellipsoid	In: As the WSV with same name.
lat_grid	In: As the WSV with same name.
lon_grid	In: As the WSV with same name.
rte_pos	In: As the WSV with same name.

Author: Patrick Eriksson

Date: 2012-03-27

Definition at line 1081 of file geodetic.cc.

References gridpos(), last(), ConstVectorView::nelem(), refell2d(), and refell2r().

Referenced by ppathFromRtePos2(), and rte_losGeometricFromRtePosToRtePos2().

◆ poslos2cart() [1/2]

void poslos2cart	(	Numeric &	x,
		Numeric &	z,
		Numeric &	dx,
		Numeric &	dz,
		const Numeric &	r,
		const Numeric &	lat,
		const Numeric &	za
	)

poslos2cart

2D version of poslos2cart

Parameters

x	Out: x-coordinate of observation position.
z	Out: z-coordinate of observation position.
dx	Out: x-part of LOS unit vector.
dz	Out: z-part of LOS unit vector.
r	Radius of observation position.
lat	Latitude of observation position.
za	LOS zenith angle at observation position.

Author: Patrick Eriksson

Date: 2012-03-20

Definition at line 355 of file geodetic.cc.

References DEG2RAD.

Referenced by defocusing_general_sub(), do_gridcell_2d_byltest(), do_gridcell_3d(), do_gridcell_3d_byltest(), geompath_tanpos_3d(), ppath_start_stepping(), ppathFromRtePos2(), and raytrace_3d_linear_basic().

◆ poslos2cart() [2/2]

void poslos2cart	(	Numeric &	x,
		Numeric &	y,
		Numeric &	z,
		Numeric &	dx,
		Numeric &	dy,
		Numeric &	dz,
		const Numeric &	r,
		const Numeric &	lat,
		const Numeric &	lon,
		const Numeric &	za,
		const Numeric &	aa
	)

poslos2cart

Conversion from position and LOS to cartesian coordinates

A position (in geographical coordinates) and LOS are converted to a cartesian position and a viewing vector. The viewing direction is the the vector [dx,dy,dz]. This vector is normalised (it has length 1).

See the user guide for definition on the zenith and azimuth angles.

Parameters

x	Out: x-coordinate of observation position.
y	Out: y-coordinate of observation position.
z	Out: z-coordinate of observation position.
dx	Out: x-part of LOS unit vector.
dy	Out: y-part of LOS unit vector.
dz	Out: z-part of LOS unit vector.
r	Radius of observation position.
lat	Latitude of observation position.
lon	Longitude of observation position.
za	LOS zenith angle at observation position.
aa	LOS azimuth angle at observation position.

Author: Patrick Eriksson

Date: 2002-12-30

Definition at line 997 of file geodetic.cc.

References abs, DEG2RAD, POLELAT, and sign().

◆ refell2d()

Numeric refell2d	(	ConstVectorView	refellipsoid,
		ConstVectorView	lat_grid,
		const GridPos	gp
	)

refell2d

Reference ellipsoid radius for points inside 2D and 3D atmospheres.

To be consistent with the ppath calculations, the ellipsoid radius shall be treated to vary linear between the latitude grid points. This function performs this operation. The latitude position is specified by its grid position (gp).

Returns: Ellispoid radius

Parameters

refellipsoid	In: As the WSV with same name.
lat_grid	In: As the WSV with same name.
gp	In: Latitude grid position.

Author: Patrick Eriksson

Date: 2012-02-09

Definition at line 1174 of file geodetic.cc.

References GridPos::fd, GridPos::idx, and refell2r().

Referenced by get_refr_index_2d(), get_refr_index_3d(), pos2refell_r(), ppath_start_stepping(), and specular_losCalc().

◆ refell2r()

Numeric refell2r	(	ConstVectorView	refellipsoid,
		const Numeric &	lat
	)

refell2r

Reference ellipsoid radius, directly from refellipsoid.

Gives the distance from the Earth's centre and the reference ellipsoid as a function of geoCENTRIC latitude.

For 1D, extract r directly as refellipsoid[0] to save time.

This is the basic function to calculate the reference ellipsoid radius. However, inside the atmosphere this radius is just used at the positions of the lat_grid. A linear interpolation is applied between these points. This is handled by other functions. For 2D and 3D and the grid position is known, use refell2d. The function pos2refell_r handles all this in a general way (but not always the fastest option).

Returns: Ellispoid radius

Parameters

refellipsoid	In: As the WSV with same name.
latitude	In: A geoecentric latitude.

Author: Patrick Eriksson

Date: 2012-02-07

Definition at line 1135 of file geodetic.cc.

References ConstVectorView::nelem().

Referenced by cloud_ppath_update3D(), defocusing_general(), plevel_slope_2d(), plevel_slope_3d(), pos2refell_r(), ppath_end_2d(), ppath_end_3d(), ppath_start_2d(), ppath_start_3d(), ppath_start_stepping(), refell2d(), refellipsoidOrbitPlane(), and wind_u_fieldIncludePlanetRotation().

◆ sph2cart()

void sph2cart	(	Numeric &	x,
		Numeric &	y,
		Numeric &	z,
		const Numeric &	r,
		const Numeric &	lat,
		const Numeric &	lon
	)

sph2cart

Conversion from spherical to cartesian coordinates.

The cartesian coordinate system is defined such as the x-axis goes along lat=0 and lon=0, the z-axis goes along lat=0 and lon=90, and z-axis goes along lat=90.

Parameters

x	Out: x position.
y	Out: y position.
z	Out: z position.
r	Radius.
lat	Latitude.
lon	Longitude.

Author: Patrick Eriksson

Date: 2002-12-17

Definition at line 1236 of file geodetic.cc.

References abs, and DEG2RAD.

Referenced by distance3D(), ppathFromRtePos2(), and rte_losGeometricFromRtePosToRtePos2().

◆ sphdist()

Numeric sphdist	(	const Numeric &	lat1,
		const Numeric &	lon1,
		const Numeric &	lat2,
		const Numeric &	lon2
	)

sphdist

The distance between two geograpgical positions

"As-the-crow-flies" angular distance between two points, specified by their latitude and longitude.

Note that angular distance is returned. The distance in length varies with altitude.

Returns: Angular distance (in degrees)

Parameters

lat1	Latitude of position 1.
lon1	Longitude of position 1.
lat2	Latitude of position 2.
lon2	Longitude of position 2.

Author: Patrick Eriksson

Date: 2012-04-05

Definition at line 1205 of file geodetic.cc.

References DEG2RAD, RAD2DEG, and sqrt().

Referenced by bending_angle1d(), surfaceTelsem(), and telsemStandalone().

Variable Documentation

◆ DEG2RAD

const Numeric DEG2RAD

Referenced by cart2poslos(), latlon_at_aa(), los2xyz(), pol2cart(), poslos2cart(), sph2cart(), and sphdist().

◆ RAD2DEG

const Numeric RAD2DEG

Referenced by cart2pol(), cart2poslos(), cart2sph(), latlon_at_aa(), los2xyz(), and sphdist().

Functions

Variables

Detailed Description

Function Documentation

◆ cart2pol()

◆ cart2poslos() [1/2]

◆ cart2poslos() [2/2]

◆ cart2sph()

◆ cycle_lat_lon()

◆ distance2D()

◆ distance3D()

◆ geompath_tanpos_3d()

◆ latlon_at_aa()

◆ line_circle_intersect()

◆ line_sphere_intersect()

◆ lon_shiftgrid()

◆ los2xyz()

◆ pol2cart()

◆ pos2refell_r()

◆ poslos2cart() [1/2]

◆ poslos2cart() [2/2]

◆ refell2d()

◆ refell2r()

◆ sph2cart()

◆ sphdist()

Variable Documentation

◆ DEG2RAD

◆ RAD2DEG