.NET wrapper for GeographicLib::GravityCircle. More...

#include <GravityCircle.h>

Public Member Functions
	GravityCircle (const GeographicLib::GravityCircle &gc)

	~GravityCircle ()

Compute the gravitational field
double	Gravity (double lon, [System::Runtime::InteropServices::Out] double%gx, [System::Runtime::InteropServices::Out] double%gy, [System::Runtime::InteropServices::Out] double%gz)

double	Disturbance (double lon, [System::Runtime::InteropServices::Out] double%deltax, [System::Runtime::InteropServices::Out] double%deltay, [System::Runtime::InteropServices::Out] double%deltaz)

double	GeoidHeight (double lon)

void	SphericalAnomaly (double lon, [System::Runtime::InteropServices::Out] double%Dg01, [System::Runtime::InteropServices::Out] double%xi, [System::Runtime::InteropServices::Out] double%eta)

double	W (double lon, [System::Runtime::InteropServices::Out] double%gX, [System::Runtime::InteropServices::Out] double%gY, [System::Runtime::InteropServices::Out] double%gZ)

double	V (double lon, [System::Runtime::InteropServices::Out] double%GX, [System::Runtime::InteropServices::Out] double%GY, [System::Runtime::InteropServices::Out] double%GZ)

double	T (double lon, [System::Runtime::InteropServices::Out] double%deltaX, [System::Runtime::InteropServices::Out] double%deltaY, [System::Runtime::InteropServices::Out] double%deltaZ)

double	T (double lon)

Private Member Functions
	!GravityCircle (void)

Private Attributes
const GeographicLib::GravityCircle *	m_pGravityCircle

Inspector functions
property bool	Init { bool get()

property double	MajorRadius { double get()

property double	Flattening { double get()

property double	Latitude { double get()

property double	Height { double get()

GravityModel::Mask	Capabilities ()

bool	Capabilities (GravityModel::Mask testcaps)

Detailed Description

.NET wrapper for GeographicLib::GravityCircle.

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

Evaluate the earth's gravity field on a circle of constant height and latitude. This uses a CircularEngine to pre-evaluate the inner sum of the spherical harmonic sum, allowing the values of the field at several different longitudes to be evaluated rapidly.

Use GravityModel::Circle to create a GravityCircle object. (The constructor for this class is private.)

See gravityparallel for an example of using GravityCircle (together with OpenMP) to speed up the computation of geoid heights.

C# Example:

using System;
using NETGeographicLib;
namespace example_GravityCircle
{
    class Program
    {
        static void Main(string[] args)
        {
            try {
                GravityModel grav = new GravityModel("egm96", "");
                double lat = 27.99, lon0 = 86.93, h = 8820; // Mt Everest
                {
                    // Slow method of evaluating the values at several points on a circle of
                    // latitude.
                    for (int i = -5; i <= 5; ++i) {
                        double lon = lon0 + i * 0.2;
                        double gx, gy, gz;
                        grav.Gravity(lat, lon, h, out gx, out gy, out gz);
                        Console.WriteLine(String.Format("{0} {1} {2} {3}", lon, gx, gy, gz));
                    }
                }
                {
                    // Fast method of evaluating the values at several points on a circle of
                    // latitude using GravityCircle.
                    GravityCircle circ = grav.Circle(lat, h, GravityModel.Mask.ALL);
                    for (int i = -5; i <= 5; ++i) {
                        double lon = lon0 + i * 0.2;
                        double gx, gy, gz;
                        circ.Gravity(lon, out gx, out gy, out gz);
                        Console.WriteLine(String.Format("{0} {1} {2} {3}", lon, gx, gy, gz));
                    }
                }
            }
            catch (GeographicErr e) {
                Console.WriteLine(String.Format("Caught exception: {0}", e.Message));
            }
        }
    }
}

Managed C++ Example:

// Example of using the GeographicLib::GravityCircle class
#include <iostream>
#include <exception>
#include <GeographicLib/GravityModel.hpp>
#include <GeographicLib/GravityCircle.hpp>
using namespace std;
using namespace GeographicLib;
int main() {
  try {
    GravityModel grav("egm96");
    double lat = 27.99, lon0 = 86.93, h = 8820; // Mt Everest
    {
      // Slow method of evaluating the values at several points on a circle of
      // latitude.
      for (int i = -5; i <= 5; ++i) {
        double lon = lon0 + i * 0.2;
        double gx, gy, gz;
        grav.Gravity(lat, lon, h, gx, gy, gz);
        cout << lon << " " << gx << " " << gy << " " << gz << "\n";
      }
    }
    {
      // Fast method of evaluating the values at several points on a circle of
      // latitude using GravityCircle.
      GravityCircle circ = grav.Circle(lat, h);
      for (int i = -5; i <= 5; ++i) {
        double lon = lon0 + i * 0.2;
        double gx, gy, gz;
        circ.Gravity(lon, gx, gy, gz);
        cout << lon << " " << gx << " " << gy << " " << gz << "\n";
      }
    }
  }
  catch (const exception& e) {
    cerr << "Caught exception: " << e.what() << "\n";
    return 1;
  }
}

Visual Basic Example:

Imports NETGeographicLib
Module example_GravityCircle
    Sub Main()
        Try
            Dim grav As GravityModel = New GravityModel("egm96", "")
            Dim lat As Double = 27.99, lon0 = 86.93, h = 8820 ' Mt Everest
            ' Slow method of evaluating the values at several points on a circle of
            ' latitude.
            For i As Integer = -5 To 5
                Dim lon As Double = lon0 + i * 0.2
                Dim gx, gy, gz As Double
                grav.Gravity(lat, lon, h, gx, gy, gz)
                Console.WriteLine(String.Format("{0} {1} {2} {3}", lon, gx, gy, gz))
            Next
            ' Fast method of evaluating the values at several points on a circle of
            ' latitude using GravityCircle.
            Dim circ As GravityCircle = grav.Circle(lat, h, GravityModel.Mask.ALL)
            For i As Integer = -5 To 5
                Dim lon As Double = lon0 + i * 0.2
                Dim gx, gy, gz As Double
                circ.Gravity(lon, gx, gy, gz)
                Console.WriteLine(String.Format("{0} {1} {2} {3}", lon, gx, gy, gz))
            Next
        Catch ex As GeographicErr
            Console.WriteLine(String.Format("Caught exception: {0}", ex.Message))
        End Try
    End Sub
End Module

INTERFACE DIFFERENCES:
The following functions are implemented as properties: Init, MajorRadius, Flattening, Latitude, and Height.

The Capabilities functions accept and return the "capabilities mask" as a NETGeographicLib::GravityModel::Mask rather than an unsigned.

Definition at line 45 of file GravityCircle.h.

Constructor & Destructor Documentation

GravityCircle::!GravityCircle ( void )

private

Definition at line 20 of file dotnet/NETGeographicLib/GravityCircle.cpp.

GravityCircle::GravityCircle ( const GeographicLib::GravityCircle & gc )

A constructor that is initialized from an unmanaged GeographicLib::GravityCircle. For internal use only. Developers should use GravityModel::Circle to create a GavityCircle object.

Definition at line 30 of file dotnet/NETGeographicLib/GravityCircle.cpp.

NETGeographicLib::GravityCircle::~GravityCircle ( )

inline

The destructor calls the finalizer.

Definition at line 64 of file GravityCircle.h.

Member Function Documentation

GravityModel::Mask GravityCircle::Capabilities ( )

Returns: caps the computational capabilities that this object was constructed with.

Definition at line 173 of file dotnet/NETGeographicLib/GravityCircle.cpp.

bool GravityCircle::Capabilities ( GravityModel::Mask testcaps )

Parameters

[in] testcaps a set of bitor'ed GeodesicLine::mask values.

Returns: true if the GeodesicLine object has all these capabilities.

Definition at line 177 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::Disturbance	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	deltax,
		[System::Runtime::InteropServices::Out] double%	deltay,
		[System::Runtime::InteropServices::Out] double%	deltaz
	)

Evaluate the gravity disturbance vector.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	deltax	the easterly component of the disturbance vector (m s⁻²).
[out]	deltay	the northerly component of the disturbance vector (m s⁻²).
[out]	deltaz	the upward component of the disturbance vector (m s⁻²).

Returns: T the corresponding disturbing potential.

Definition at line 57 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::GeoidHeight ( double lon )

Evaluate the geoid height.

Parameters

[in] lon the geographic longitude (degrees).

Returns: N the height of the geoid above the reference ellipsoid (meters).

Some approximations are made in computing the geoid height so that the results of the NGA codes are reproduced accurately. Details are given in gravitygeoid.

Definition at line 71 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::Gravity	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	gx,
		[System::Runtime::InteropServices::Out] double%	gy,
		[System::Runtime::InteropServices::Out] double%	gz
	)

Evaluate the gravity.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	gx	the easterly component of the acceleration (m s⁻²).
[out]	gy	the northerly component of the acceleration (m s⁻²).
[out]	gz	the upward component of the acceleration (m s⁻²); this is usually negative.

Returns: W the sum of the gravitational and centrifugal potentials.

The function includes the effects of the earth's rotation.

Definition at line 43 of file dotnet/NETGeographicLib/GravityCircle.cpp.

void GravityCircle::SphericalAnomaly	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	Dg01,
		[System::Runtime::InteropServices::Out] double%	xi,
		[System::Runtime::InteropServices::Out] double%	eta
	)

Evaluate the components of the gravity anomaly vector using the spherical approximation.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	Dg01	the gravity anomaly (m s⁻²).
[out]	xi	the northerly component of the deflection of the vertical (degrees).
[out]	eta	the easterly component of the deflection of the vertical (degrees).

The spherical approximation (see Heiskanen and Moritz, Sec 2-14) is used so that the results of the NGA codes are reproduced accurately. approximations used here. Details are given in gravitygeoid.

Definition at line 77 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::T	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	deltaX,
		[System::Runtime::InteropServices::Out] double%	deltaY,
		[System::Runtime::InteropServices::Out] double%	deltaZ
	)

Evaluate the components of the gravity disturbance in geocentric coordinates.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	deltaX	the X component of the gravity disturbance (m s⁻²).
[out]	deltaY	the Y component of the gravity disturbance (m s⁻²).
[out]	deltaZ	the Z component of the gravity disturbance (m s⁻²).

Returns: T = W - U the disturbing potential (also called the anomalous potential) (m² s⁻²).

Definition at line 118 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::T ( double lon )

Evaluate disturbing potential in geocentric coordinates.

Parameters

[in] lon the geographic longitude (degrees).

Returns: T = W - U the disturbing potential (also called the anomalous potential) (m² s⁻²).

Definition at line 132 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::V	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	GX,
		[System::Runtime::InteropServices::Out] double%	GY,
		[System::Runtime::InteropServices::Out] double%	GZ
	)

Evaluate the components of the acceleration due to gravity in geocentric coordinates.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	GX	the X component of the acceleration (m s⁻²).
[out]	GY	the Y component of the acceleration (m s⁻²).
[out]	GZ	the Z component of the acceleration (m s⁻²).

Returns: V = W - Φ the gravitational potential (m² s⁻²).

Definition at line 104 of file dotnet/NETGeographicLib/GravityCircle.cpp.

double GravityCircle::W	(	double	lon,
		[System::Runtime::InteropServices::Out] double%	gX,
		[System::Runtime::InteropServices::Out] double%	gY,
		[System::Runtime::InteropServices::Out] double%	gZ
	)

Evaluate the components of the acceleration due to gravity and the centrifugal acceleration in geocentric coordinates.

Parameters

[in]	lon	the geographic longitude (degrees).
[out]	gX	the X component of the acceleration (m s⁻²).
[out]	gY	the Y component of the acceleration (m s⁻²).
[out]	gZ	the Z component of the acceleration (m s⁻²).

Returns: W = V + Φ the sum of the gravitational and centrifugal potentials (m² s⁻²).

Definition at line 90 of file dotnet/NETGeographicLib/GravityCircle.cpp.

Member Data Documentation

property double NETGeographicLib::GravityCircle::Flattening { double get()

Returns: f the flattening of the ellipsoid. This is the value inherited from the GravityModel object used in the constructor. This property throws an exception if the GravityCircles has not been initialized.

Definition at line 230 of file GravityCircle.h.

property double NETGeographicLib::GravityCircle::Height { double get()

Returns: the height of the circle (meters). This property throws an exception if the GravityCircles has not been initialized.

Definition at line 244 of file GravityCircle.h.

property bool NETGeographicLib::GravityCircle::Init { bool get()

Returns: true if the object has been initialized.

Definition at line 213 of file GravityCircle.h.

property double NETGeographicLib::GravityCircle::Latitude { double get()

Returns: the latitude of the circle (degrees). This property throws an exception if the GravityCircles has not been initialized.

Definition at line 237 of file GravityCircle.h.

const GeographicLib::GravityCircle* NETGeographicLib::GravityCircle::m_pGravityCircle

private

Definition at line 49 of file GravityCircle.h.

property double NETGeographicLib::GravityCircle::MajorRadius { double get()

Returns: a the equatorial radius of the ellipsoid (meters). This is the value inherited from the GravityModel object used in the constructor. This property throws an exception if the GravityCircles has not been initialized.

Definition at line 222 of file GravityCircle.h.

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

Public Member Functions

Private Member Functions

Private Attributes

Inspector functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation