Murl::Util::GeoLocation Class Reference

The geo location class. More...

#include "murl_util_geo_location.h"

Public Member Functions
	GeoLocation ()
	The default constructor.
	GeoLocation (Double latitude, Double longitude, Double altitude)
	The constructor taking separate location values. More...
Bool	IsZero () const
	Check if the location is zero. More...
Double	GetDistance (const GeoLocation &location) const
	Calculate the distance from this location to a geo location. More...
Double	GetBearing (const GeoLocation &location) const
	Calculate the bearing angle between this and a geo locations. More...
GeoLocation	GetDestination (Double distance, Double bearing) const
	Calculate the destination geo location by a given distance and bearing from this location. More...

Static Public Member Functions
static Matrix	GetRotationMatrix (const Input::AccelerationVector &acceleration, const Input::MagneticFieldVector &geomagnetic)
	Get the rotation matrix from acceleration and geomagnetic values. More...
static Vector	GetRotationAngles (const Matrix &rotation)
	Get the geo rotation angles from a rotation matrix. More...

Public Attributes
Double	mLatitude
	The latitude in degrees relative to the equator.
Double	mLongitude
	The longitude in degrees relative to the zero meridian.
Double	mAltitude
	The altitude above sea level in meters.
Double	mRadius
	The sphere radius in meters, default is the idealized earth radius of 6371000 meters.

Detailed Description

The geo location class.

Constructor & Destructor Documentation

GeoLocation()

Murl::Util::GeoLocation::GeoLocation	(	Double	latitude,
		Double	longitude,
		Double	altitude
	)

The constructor taking separate location values.

Parameters

latitude	The latitude in degrees relative to the equator.
longitude	The longitude in degrees relative to the zero meridian.
altitude	The altitude above sea level in meters.

Member Function Documentation

GetRotationMatrix()

static Matrix Murl::Util::GeoLocation::GetRotationMatrix ( const Input::AccelerationVector &  acceleration, const Input::MagneticFieldVector &  geomagnetic  )

static

Get the rotation matrix from acceleration and geomagnetic values.

Parameters

acceleration	The acceleration vector.
geomagnetic	The geomagnetic field vector.

Returns

The rotation matrix.

GetRotationAngles()

static Vector Murl::Util::GeoLocation::GetRotationAngles ( const Matrix &  rotation )

static

Get the geo rotation angles from a rotation matrix.

Extracts the following rotation angles:

• Sets the vector member x to the pitch angle.
• Sets the vector member y to the roll angle.
• Sets the vector member z to the azimuth angle.

  Parameters

  rotation

  The rotation matrix, typically from GetRotationMatrix().

  Returns

  The geo rotation angles in radiants.

IsZero()

Bool Murl::Util::GeoLocation::IsZero

(

)

const

Check if the location is zero.

Returns

true if all location members are zero.

GetDistance()

Double Murl::Util::GeoLocation::GetDistance

(

const GeoLocation &

location

)

const

Calculate the distance from this location to a geo location.

The formula calculates on the basis of a spherical earth (ignoring ellipsoidal effects) which is accurate enough for most purposes. The altitude is not considered.
The calculation uses the simple spherical law of cosines formula.
distance = acos(sin(φ1) * sin(φ2) + cos(φ1) * cos(φ2) * cos(Δλ)) * earth radius.

Parameters

location

The geo location.

Returns

The distance to the geo location in meters.

GetBearing()

Double Murl::Util::GeoLocation::GetBearing

(

const GeoLocation &

location

)

const

Calculate the bearing angle between this and a geo locations.

The formula calculates on the basis of a spherical earth (ignoring ellipsoidal effects) which is accurate enough for most purposes. The altitude is not considered.
The formula is for the initial bearing (sometimes referred to as forward azimuth) which if followed in a straight line along a great circle arc will take you from the start point to the end point.
θ = atan2(sin(Δλ) * cos(φ2), cos(φ1) * sin(φ2) − sin(φ1) * cos(φ2) * cos(Δλ)).

Parameters

location

The geo location.

Returns

The bearing angle between this and the geo location in degrees in range [0 .. 360).

GetDestination()

GeoLocation Murl::Util::GeoLocation::GetDestination	(	Double	distance,
		Double	bearing
	)		const

Calculate the destination geo location by a given distance and bearing from this location.

The formula calculates on the basis of a spherical earth (ignoring ellipsoidal effects) which is accurate enough for most purposes.
Given a start point, initial bearing, and distance, this will calculate the destination point travelling along a great circle arc.
φ2 = asin(sin(φ1) * cos(d / R) + cos(φ1) * sin(d / R) * cos(θ))
λ2 = λ1 + atan2(sin(θ) * sin(d / R) * cos(φ1), cos(d / R) − sin(φ1) * sin(φ2))
φ is latitude, λ is longitude, θ is the bearing (clockwise from north), d is the distance, R is the earth’s radius (d / R is the angular distance).

Parameters

distance	The distance to the destination geo location in meters.
bearing	The bearing to the destination geo location in degrees.

Returns

The destination geo location including the altitude from this location.

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

• murl_util_geo_location.h