Package noaa.coastwatch.util.trans

Class Datum

java.lang.Object

noaa.coastwatch.util.trans.Datum

All Implemented Interfaces:

SpheroidConstants

public class Datum
extends Object
implements SpheroidConstants

A Datum holds a geodetic datum name, spheroid name, spheroid parameters, and WGS84-relative datum transformation parameters. The datum may be used to transform EarthLocation objects to and from different datums.

Since:

3.2.0

Author:

Peter Hollemans

Field Summary

Fields inherited from interface noaa.coastwatch.util.trans.SpheroidConstants

AIRY, AUS_NAT, BESSEL, CLARKE1866, CLARKE1880, EVEREST, GRS1980, HOUGH, INT1909, INT1967, KRASS, MAX_SPHEROIDS, MERCURY1960, MOD_AIRY, MOD_EVEREST, MOD_MER1968, SE_ASIA, SPHERE, SPHEROID_INV_FLAT, SPHEROID_NAMES, SPHEROID_SEMI_MAJOR, SPHEROID_SEMI_MINOR, STD_RADIUS, WGS66, WGS72, WGS84

Constructor Summary

Constructors

Constructor	Description
Datum(String datumName, int spheroid, double dx, double dy, double dz)	Creates a new geodetic datum based on a spheroid code.
Datum(String datumName, String spheroidName, double axis, double invFlat, double dx, double dy, double dz)	Creates a new geodetic datum based on user-specified spheroid parameters.

Method Summary

Modifier and Type	Method	Description
Object	clone()
void	computeECF(double lat, double lon, double[] ecf)	Converts an earth location to Earth-Centered-Fixed (ECF).
boolean	equals(Object obj)
double	getAxis()	Gets the semi-major axis in meters.
String	getDatumName()	Gets the datum name.
double	getE2()	Gets the eccentricity value squared.
double	getFlat()	Gets the flattening value.
String	toString()
static EarthLocation	transform(EarthLocation from, Datum toDatum, EarthLocation to)	Transforms an earth location from one datum to another.

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

Datum

public Datum(String datumName,
 String spheroidName,
 double axis,
 double invFlat,
 double dx,
 double dy,
 double dz)

Creates a new geodetic datum based on user-specified spheroid parameters.

Parameters:

datumName - the datum name.

spheroidName - the spheroid name.

axis - the spheroid semi-major axis (meters).

invFlat - the spheroid inverse flattening.

dx - the x-axis shift (meters).

dy - the y-axis shift (meters).

dz - the z-axis shift (meters).

Datum

public Datum(String datumName,
 int spheroid,
 double dx,
 double dy,
 double dz)

Creates a new geodetic datum based on a spheroid code.

Parameters:

datumName - the datum name.

spheroid - the spheroid code for the datum.

dx - the x-axis shift (meters).

dy - the y-axis shift (meters).

dz - the z-axis shift (meters).

Method Details

getAxis

public double getAxis()

Gets the semi-major axis in meters.

getFlat

public double getFlat()

Gets the flattening value.

getE2

public double getE2()

Gets the eccentricity value squared.

getDatumName

public String getDatumName()

Gets the datum name.

transform

public static EarthLocation transform(EarthLocation from,
 Datum toDatum,
 EarthLocation to)

Transforms an earth location from one datum to another.

Parameters:

from - the earth location to transform.

toDatum - the new datum to transform to.

to - the earth location to modify, or null to create a new transformed earth location. The to and from locations may be the same, in which case the location is modified in-place.

Returns:

the new or modified earth location. The returned location will have its datum set to the new datum.

computeECF

public void computeECF(double lat,
 double lon,
 double[] ecf)

Converts an earth location to Earth-Centered-Fixed (ECF). This is a right-handed cartesian coordinate system centered at the center of the Earth ellipsoid, with its x-axis pointing towards (0N, 0E), its y-axis pointing towards (0N, 90E), and its z-axis pointing at the north pole.

Parameters:

lat - the latitude in the range [-90..90].

lon - the longitude in the range [-180..180].

ecf - the output ECF coordinates in meters.

Since:

3.5.0

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

clone

public Object clone()

Overrides:

clone in class Object