com.bbn.openmap.proj.coords
Class ECEFPoint

java.lang.Object
  com.bbn.openmap.proj.coords.ECEFPoint

public class ECEFPoint
extends java.lang.Object

From: http://www.commlinx.com.au/Datum%20Transformation%20Description.html :

The Cartesian coordinate frame of reference used in GPS/GLONASS is called Earth-Centered, Earth-Fixed (ECEF). ECEF uses three-dimensional XYZ coordinates (in meters) to describe the location of a GPS user or satellite. The term "Earth- Centered" comes from the fact that the origin of the axis (0,0,0) is located at the mass center of gravity (determined through years of tracking satellite trajectories). The term "Earth-Fixed" implies that the axes are fixed with respect to the earth (that is, they rotate with the earth). The Z-axis pierces the North Pole, and the XY-axis defines the equatorial plane (Figure 1).

ECEF coordinates are expressed in a reference system that is related to mapping representations. Because the earth has a complex shape, a simple, yet accurate, method to approximate the earth's shape is required. The use of a reference ellipsoid allows for the conversion of the ECEF coordinates to the more commonly used geodetic-mapping coordinates of Latitude, Longitude, and Altitude (LLA).

Field Summary

protected static double	EQUIVALENT_TOLERANCE
protected double	x_
protected double	y_
protected double	z_

Constructor Summary

ECEFPoint()
Construct a default ECEFPoint.

ECEFPoint(double x, double y, double z)
Construct an ECEFPoint

ECEFPoint(ECEFPoint pt)
Construct an ECEFPoint

ECEFPoint(float x, float y, float z)
Construct an ECEFPoint

Method Summary

boolean	equals(java.lang.Object obj) Determines whether two ECEFPoints are equal.
LatLonPoint	getLatLon() Return a LatLonPoint in WGS 84
java.awt.geom.Point2D	getLatLon(Ellipsoid ellip, java.awt.geom.Point2D ret) Return a Point2D in the given Ellipsoid with longitude as x and latitude as y
LatLonPoint	getLatLon(LatLonPoint instance) Return a LatLonPoint in WGS 84
double	getx() Get x
double	gety() Get y
double	getz() Get z
int	hashCode()
static ECEFPoint	LLtoECEF(LatLonPoint llpoint)
static ECEFPoint	LLtoECEF(LatLonPoint llpoint, ECEFPoint ecef)
void	read(java.io.DataInputStream s) Read object.
void	setECEF(double x, double y, double z) Set x y z.
void	setECEF(ECEFPoint pt) Set ECEFPoint.
void	setLatLon(double lat, double lon, Ellipsoid ellip) Set an ECEFPoint from a Lat, Lon
void	setLatLon(float lat, float lon) Set an ECEFPoint from a Lat, Lon
void	setLatLon(LatLonPoint pt) Set an ECEFPoint from a LatLonPoint
void	setx(double x) Set x.
void	sety(double y) Set y.
void	setz(double z) Set z.
java.lang.String	toString() Returns a string representation of the object.
void	write(java.io.DataOutputStream s) Write object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

EQUIVALENT_TOLERANCE

protected static double EQUIVALENT_TOLERANCE

x_

protected double x_

y_

protected double y_

z_

protected double z_

Constructor Detail

ECEFPoint

public ECEFPoint()

Construct a default ECEFPoint.

ECEFPoint

public ECEFPoint(double x,
                 double y,
                 double z)

Construct an ECEFPoint

ECEFPoint

public ECEFPoint(ECEFPoint pt)

Construct an ECEFPoint

Parameters:

pt - ECEFPoint

ECEFPoint

public ECEFPoint(float x,
                 float y,
                 float z)

Construct an ECEFPoint

Method Detail

LLtoECEF

public static ECEFPoint LLtoECEF(LatLonPoint llpoint)

LLtoECEF

public static ECEFPoint LLtoECEF(LatLonPoint llpoint,
                                 ECEFPoint ecef)

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

String representation

setx

public void setx(double x)

Set x.

sety

public void sety(double y)

Set y.

setz

public void setz(double z)

Set z.

setECEF

public void setECEF(double x,
                    double y,
                    double z)

Set x y z.

setECEF

public void setECEF(ECEFPoint pt)

Set ECEFPoint.

getx

public double getx()

Get x

gety

public double gety()

Get y

getz

public double getz()

Get z

equals

public boolean equals(java.lang.Object obj)

Determines whether two ECEFPoints are equal.

Overrides:

equals in class java.lang.Object

Parameters:

obj - Object

Returns:

Whether the two points are equal

write

public void write(java.io.DataOutputStream s)
           throws java.io.IOException

Write object.

Parameters:

s - DataOutputStream

Throws:

java.io.IOException

read

public void read(java.io.DataInputStream s)
          throws java.io.IOException

Read object.

Parameters:

s - DataInputStream

Throws:

java.io.IOException

setLatLon

public void setLatLon(LatLonPoint pt)

Set an ECEFPoint from a LatLonPoint

Parameters:

pt - LatLonPoint

setLatLon

public void setLatLon(float lat,
                      float lon)

Set an ECEFPoint from a Lat, Lon

setLatLon

public void setLatLon(double lat,
                      double lon,
                      Ellipsoid ellip)

Set an ECEFPoint from a Lat, Lon

getLatLon

public LatLonPoint getLatLon()

Return a LatLonPoint in WGS 84

getLatLon

public LatLonPoint getLatLon(LatLonPoint instance)

Return a LatLonPoint in WGS 84

getLatLon

public java.awt.geom.Point2D getLatLon(Ellipsoid ellip,
                                       java.awt.geom.Point2D ret)

Return a Point2D in the given Ellipsoid with longitude as x and latitude as y

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object