NETGeographicLib  1.43
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NETGeographicLib::LocalCartesian Class Reference

.NET wrapper for GeographicLib::LocalCartesian. More...

#include <NETGeographicLib/LocalCartesian.h>

Public Member Functions

 LocalCartesian (double lat0, double lon0, double h0, Geocentric^ earth)
 
 LocalCartesian (double lat0, double lon0, double h0)
 
 LocalCartesian (Geocentric^ earth)
 
 LocalCartesian ()
 
 ~LocalCartesian ()
 
void Reset (double lat0, double lon0, double h0)
 
void Forward (double lat, double lon, double h, [System::Runtime::InteropServices::Out] double% x, [System::Runtime::InteropServices::Out] double% y, [System::Runtime::InteropServices::Out] double% z)
 
void Forward (double lat, double lon, double h, [System::Runtime::InteropServices::Out] double% x, [System::Runtime::InteropServices::Out] double% y, [System::Runtime::InteropServices::Out] double% z, [System::Runtime::InteropServices::Out] array< double, 2 >^%M)
 
void Reverse (double x, double y, double z, [System::Runtime::InteropServices::Out] double% lat, [System::Runtime::InteropServices::Out] double% lon, [System::Runtime::InteropServices::Out] double% h)
 
void Reverse (double x, double y, double z, [System::Runtime::InteropServices::Out] double% lat, [System::Runtime::InteropServices::Out] double% lon, [System::Runtime::InteropServices::Out] double% h, [System::Runtime::InteropServices::Out] array< double, 2 >^%M)
 

Properties

Inspector functions
double LatitudeOrigin [get]
 
double LongitudeOrigin [get]
 
double HeightOrigin [get]
 
double MajorRadius [get]
 
double Flattening [get]
 

Detailed Description

.NET wrapper for GeographicLib::LocalCartesian.

This class allows .NET applications to access GeographicLib::LocalCartesian.

Convert between geodetic coordinates latitude = lat, longitude = lon, height = h (measured vertically from the surface of the ellipsoid) to local cartesian coordinates (x, y, z). The origin of local cartesian coordinate system is at lat = lat0, lon = lon0, h = h0. The z axis is normal to the ellipsoid; the y axis points due north. The plane z = - h0 is tangent to the ellipsoid.

The conversions all take place via geocentric coordinates using a Geocentric object.

C# Example:

using System;
using NETGeographicLib;
namespace example_LocalCartesian
{
class Program
{
static void Main(string[] args)
{
try {
Geocentric earth = new Geocentric();
const double lat0 = 48 + 50/60.0, lon0 = 2 + 20/60.0; // Paris
LocalCartesian proj = new LocalCartesian(lat0, lon0, 0, earth);
{
// Sample forward calculation
double lat = 50.9, lon = 1.8, h = 0; // Calais
double x, y, z;
proj.Forward(lat, lon, h, out x, out y, out z);
Console.WriteLine(String.Format("{0} {1} {2}", x, y, z));
}
{
// Sample reverse calculation
double x = -38e3, y = 230e3, z = -4e3;
double lat, lon, h;
proj.Reverse(x, y, z, out lat, out lon, out h);
Console.WriteLine(String.Format("{0} {1} {2}", lat, lon, h));
}
}
catch (GeographicErr e) {
Console.WriteLine(String.Format("Caught exception: {0}", e.Message));
}
}
}
}

Managed C++ Example:

using namespace System;
using namespace NETGeographicLib;
int main(array<System::String ^> ^/*args*/)
{
try {
Geocentric^ earth = gcnew Geocentric();
const double lat0 = 48 + 50/60.0, lon0 = 2 + 20/60.0; // Paris
LocalCartesian^ proj = gcnew LocalCartesian(lat0, lon0, 0, earth);
{
// Sample forward calculation
double lat = 50.9, lon = 1.8, h = 0; // Calais
double x, y, z;
proj->Forward(lat, lon, h, x, y, z);
Console::WriteLine(String::Format("{0} {1} {2}", x, y, z));
}
{
// Sample reverse calculation
double x = -38e3, y = 230e3, z = -4e3;
double lat, lon, h;
proj->Reverse(x, y, z, lat, lon, h);
Console::WriteLine(String::Format("{0} {1} {2}", lat, lon, h));
}
}
catch (GeographicErr^ e) {
Console::WriteLine(String::Format("Caught exception: {0}", e->Message));
return -1;
}
return 0;
}

Visual Basic Example:

Imports NETGeographicLib
Module example_LocalCartesian
Sub Main()
Try
Dim earth As Geocentric = New Geocentric()
Dim lat0 As Double = 48 + 50 / 60.0, lon0 = 2 + 20 / 60.0 ' Paris
Dim proj As LocalCartesian = New LocalCartesian(lat0, lon0, 0, earth)
' Sample forward calculation
Dim lat As Double = 50.9, lon = 1.8, h = 0 ' Calais
Dim x, y, z As Double
proj.Forward(lat, lon, h, x, y, z)
Console.WriteLine(String.Format("{0} {1} {2}", x, y, z))
' Sample reverse calculation
x = -38000.0 : y = 230000.0 : z = -4000.0
proj.Reverse(x, y, z, lat, lon, h)
Console.WriteLine(String.Format("{0} {1} {2}", lat, lon, h))
Catch ex As GeographicErr
Console.WriteLine(String.Format("Caught exception: {0}", ex.Message))
End Try
End Sub
End Module

INTERFACE DIFFERENCES:
Constructors have been provided that assume WGS84 parameters.

The following functions are implemented as properties: LatitudeOrigin, LongitudeOrigin, HeightOrigin, MajorRadius, and Flattening.

The rotation matrices returned by the Forward and Reverse functions are 2D, 3 × 3 arrays rather than vectors.

Definition at line 48 of file LocalCartesian.h.

Constructor & Destructor Documentation

NETGeographicLib::LocalCartesian::LocalCartesian ( double  lat0,
double  lon0,
double  h0,
Geocentric earth 
)

Constructor setting the origin.

Parameters
[in]lat0latitude at origin (degrees).
[in]lon0longitude at origin (degrees).
[in]h0height above ellipsoid at origin (meters); default 0.
[in]earthGeocentric object for the transformation; default Geocentric::WGS84.

lat0 should be in the range [−90°, 90°]; lon0 should be in the range [−540°, 540°).

NETGeographicLib::LocalCartesian::LocalCartesian ( double  lat0,
double  lon0,
double  h0 
)

Constructor setting the origin and assuming a WGS84 ellipsoid.

Parameters
[in]lat0latitude at origin (degrees).
[in]lon0longitude at origin (degrees).
[in]h0height above ellipsoid at origin (meters); default 0.

lat0 should be in the range [−90°, 90°]; lon0 should be in the range [−540°, 540°).

NETGeographicLib::LocalCartesian::LocalCartesian ( Geocentric earth)

Constructor that uses the provided ellipsoid.

Parameters
[in]earthGeocentric object for the transformation; default Geocentric::WGS84.

Sets lat0 = 0, lon0 = 0, h0 = 0.

NETGeographicLib::LocalCartesian::LocalCartesian ( )

The default constructor assumes the WGS84 ellipsoid.

Sets lat0 = 0, lon0 = 0, h0 = 0.

Referenced by ~LocalCartesian().

NETGeographicLib::LocalCartesian::~LocalCartesian ( )
inline

The destructor calls the finalizer.

Definition at line 105 of file LocalCartesian.h.

References LocalCartesian().

Member Function Documentation

void NETGeographicLib::LocalCartesian::Reset ( double  lat0,
double  lon0,
double  h0 
)

Reset the origin.

Parameters
[in]lat0latitude at origin (degrees).
[in]lon0longitude at origin (degrees).
[in]h0height above ellipsoid at origin (meters); default 0.

lat0 should be in the range [−90°, 90°]; lon0 should be in the range [−540°, 540°).

void NETGeographicLib::LocalCartesian::Forward ( double  lat,
double  lon,
double  h,
[System::Runtime::InteropServices::Out] double%  x,
[System::Runtime::InteropServices::Out] double%  y,
[System::Runtime::InteropServices::Out] double%  z 
)

Convert from geodetic to local cartesian coordinates.

Parameters
[in]latlatitude of point (degrees).
[in]lonlongitude of point (degrees).
[in]hheight of point above the ellipsoid (meters).
[out]xlocal cartesian coordinate (meters).
[out]ylocal cartesian coordinate (meters).
[out]zlocal cartesian coordinate (meters).

lat should be in the range [−90°, 90°]; lon should be in the range [−540°, 540°).

void NETGeographicLib::LocalCartesian::Forward ( double  lat,
double  lon,
double  h,
[System::Runtime::InteropServices::Out] double%  x,
[System::Runtime::InteropServices::Out] double%  y,
[System::Runtime::InteropServices::Out] double%  z,
[System::Runtime::InteropServices::Out] array< double, 2 >^%  M 
)

Convert from geodetic to local cartesian coordinates and return rotation matrix.

Parameters
[in]latlatitude of point (degrees).
[in]lonlongitude of point (degrees).
[in]hheight of point above the ellipsoid (meters).
[out]xlocal cartesian coordinate (meters).
[out]ylocal cartesian coordinate (meters).
[out]zlocal cartesian coordinate (meters).
[out]Ma 3 × 3 rotation matrix.

lat should be in the range [−90°, 90°]; lon should be in the range [−540°, 540°).

Let v be a unit vector located at (lat, lon, h). We can express v as column vectors in one of two ways

  • in east, north, up coordinates (where the components are relative to a local coordinate system at (lat, lon, h)); call this representation v1.
  • in x, y, z coordinates (where the components are relative to the local coordinate system at (lat0, lon0, h0)); call this representation v0.

Then we have v0 = Mv1.

void NETGeographicLib::LocalCartesian::Reverse ( double  x,
double  y,
double  z,
[System::Runtime::InteropServices::Out] double%  lat,
[System::Runtime::InteropServices::Out] double%  lon,
[System::Runtime::InteropServices::Out] double%  h 
)

Convert from local cartesian to geodetic coordinates.

Parameters
[in]xlocal cartesian coordinate (meters).
[in]ylocal cartesian coordinate (meters).
[in]zlocal cartesian coordinate (meters).
[out]latlatitude of point (degrees).
[out]lonlongitude of point (degrees).
[out]hheight of point above the ellipsoid (meters).

The value of lon returned is in the range [−180°, 180°).

void NETGeographicLib::LocalCartesian::Reverse ( double  x,
double  y,
double  z,
[System::Runtime::InteropServices::Out] double%  lat,
[System::Runtime::InteropServices::Out] double%  lon,
[System::Runtime::InteropServices::Out] double%  h,
[System::Runtime::InteropServices::Out] array< double, 2 >^%  M 
)

Convert from local cartesian to geodetic coordinates and return rotation matrix.

Parameters
[in]xlocal cartesian coordinate (meters).
[in]ylocal cartesian coordinate (meters).
[in]zlocal cartesian coordinate (meters).
[out]latlatitude of point (degrees).
[out]lonlongitude of point (degrees).
[out]hheight of point above the ellipsoid (meters).
[out]Ma 3 × 3 rotation matrix.

Let v be a unit vector located at (lat, lon, h). We can express v as column vectors in one of two ways

  • in east, north, up coordinates (where the components are relative to a local coordinate system at (lat, lon, h)); call this representation v1.
  • in x, y, z coordinates (where the components are relative to the local coordinate system at (lat0, lon0, h0)); call this representation v0.

Then we have v1 = MTv0, where MT is the transpose of M.

Property Documentation

double NETGeographicLib::LocalCartesian::LatitudeOrigin
get
Returns
latitude of the origin (degrees).

Definition at line 224 of file LocalCartesian.h.

double NETGeographicLib::LocalCartesian::LongitudeOrigin
get
Returns
longitude of the origin (degrees).

Definition at line 229 of file LocalCartesian.h.

double NETGeographicLib::LocalCartesian::HeightOrigin
get
Returns
height of the origin (meters).

Definition at line 234 of file LocalCartesian.h.

double NETGeographicLib::LocalCartesian::MajorRadius
get
Returns
a the equatorial radius of the ellipsoid (meters). This is the value of a inherited from the Geocentric object used in the constructor.

Definition at line 241 of file LocalCartesian.h.

double NETGeographicLib::LocalCartesian::Flattening
get
Returns
f the flattening of the ellipsoid. This is the value inherited from the Geocentric object used in the constructor.

Definition at line 247 of file LocalCartesian.h.


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