noaa.coastwatch.util.trans.GCTPStyleProjection

All Implemented Interfaces:: Cloneable, ProjectionConstants

Direct Known Subclasses:: GCTPCStyleProjection

public abstract class GCTPStyleProjection extends MapProjection

The GCTPStyleProjection class provides various static constants and functions for classes that perform GCTP style projection computations. The functions are based directly on those from the GCTPC package.

Since:: 3.2.1
Author:: Peter Hollemans

Field Summary

Fields

Modifier and Type

Field

Description

static final double

C3P

A useless quirky companion constant to go along with R2D.

static final double

D2R

Conversion from degrees to radians.

protected double

ec

The eccentricity value for the spheroid.

protected double

ec2

The eccentricity value squared for the spheroid.

static final double

EPSLN

The epsilon value for checking if numbers are very close.

protected double

falseEast

The false easting value.

protected double

falseNorth

The false northing value.

static final double

HALF_PI

The value of PI/2.

static final double

PI

The value of PI.

static final double

R2D

Conversion from radians to degrees.

protected double

rMajor

The semi-major axis in meters.

static final double

TWO_PI

The value of 2 PI.

Fields inherited from class noaa.coastwatch.util.trans.MapProjection
datum, DESCRIPTION, forwardAffine, inverseAffine, spheroid, system, zone

Fields inherited from class noaa.coastwatch.util.trans.EarthTransform
boundaryHandler, dims

Fields inherited from interface noaa.coastwatch.util.trans.ProjectionConstants
ALASKA, ALBERS, AZMEQD, EQRECT, EQUIDC, GEO, GNOMON, GOOD, GVNSP, HAMMER, HOM, IMOLL, LAMAZ, LAMCC, MAX_PROJECTIONS, MERCAT, MILLER, MOLL, OBEQA, ORTHO, POLYC, PROJECTION_NAMES, PS, ROBIN, SNSOID, SOM, SPCS, STEREO, TM, USDEF, UTM, VGRINT, WAGIV, WAGVII
Constructor Summary

Constructors

Constructor

Description

GCTPStyleProjection(int system, int zone, double rMajor, double rMinor, int[] dimensions, AffineTransform affine)

Creates a GCTP style projection.
Method Summary

Modifier and Type

Method

Description

static double

adjust_lon(double x)

Adjusts a longitude angle to be in the range [-180 ..

static double

asinz(double con)

Computes asin and eliminates roundoff error.

static int

calc_utm_zone(double lon)

Calculates the UTM zone number.

static double

e0fn(double x)

Computes the constant e0 which is used in a series for calculating the distance along a meridian.

static double

e1fn(double x)

Computes the constant e1 which is used in a series for calculating the distance along a meridian.

static double

e2fn(double x)

Computes the constant e2 which is used in a series for calculating the distance along a meridian.

static double

e3fn(double x)

Computes the constant e3 which is used in a series for calculating the distance along a meridian.

static double

e4fn(double x)

Computes the constant e4 used in the Polar Stereographic projection.

static double

mlfn(double e0, double e1, double e2, double e3, double phi)

Computes the value of M which is the distance along a meridian from the Equator to latitude phi.

static double

msfnz(double eccent, double sinphi, double cosphi)

Computes the constant small m which is the radius of a parallel of latitude, phi, divided by the semimajor axis.

static double

pack_angle(double angle)

Packs an angle in degrees to DDDMMMSSS.SS format.

static double

pakcz(double pak)

Converts the 2 digit alternate packed DMS format (+/-)DDDMMSS.SSS to 3 digit standard packed DMS format (+/-)DDDMMMSSS.SSS.

static double

pakr2dm(double pak)

Converts radians to 3 digit packed DMS format (+/-)DDDMMMSSS.SSS.

static double

phi1z(double eccent, double qs)

Computes the value phi1, the latitude for the inverse of the Albers Conical Equal-Area projection.

static double

phi2z(double eccent, double ts)

Computes the latitude angle, phi2, for the inverse of the Lambert Conformal Conic and Polar Stereographic projections.

static double

phi3z(double ml, double e0, double e1, double e2, double e3)

Computes the latitude, phi3, for the inverse of the Equidistant Conic projection.

static double

phi4z(double eccent, double e0, double e1, double e2, double e3, double a, double b, double[] c)

Computes phi4, the latitude for the inverse of the Polyconic projection.

static double

qsfnz(double eccent, double sinphi, double cosphi)

Computes the constant small q which is the radius of a parallel of latitude, phi, divided by the semimajor axis.

protected void

setDatum(Datum datum)

Sets the datum for this projection and pre-computes values needed and matching spheroid code.

void

setFalse(double falseEast, double falseNorth)

Sets the false east and north values.

static int

sign(double x)

Gets the sign of a value.

static void

sphdz(int isph, double[] parm, double[] r_major, double[] r_minor, double[] radius)

Gets the semi-major, semi-minor, and radius axes lengths based on the parameters and spheroid code.

static double

tsfnz(double eccent, double phi, double sinphi)

Computes the constant small t for use in the forward computations in the Lambert Conformal Conic and the Polar Stereographic projections.

static double

unpack_angle(double angle)

Unpacks an angle in DDDMMMSSS.SS format to degrees.

Methods inherited from class noaa.coastwatch.util.trans.MapProjection
clone, describe, equals, getAffine, getDatum, getModified, getParameters, getPixelDimensions, getPixelSize, getProjection, getSpheroid, getSpheroidName, getSubset, getSubset, getSystem, getSystemName, getZone, isOrientable, mapTransformFor, mapTransformInv, setAffine, setPositiveLon, transformImpl, transformImpl

Methods inherited from class noaa.coastwatch.util.trans.EarthTransform2D
get2DVersion, getBoundingBox, getWorldAxes, main, setPointTransform, transformToPoint

Methods inherited from class noaa.coastwatch.util.trans.EarthTransform
distance, getBoundaryHandler, getDimensions, getResolution, getSpheroid, getSpheroid, isInvertible, transform, transform, transform, transform

Methods inherited from class noaa.coastwatch.util.MetadataContainer
getMetadataMap

Methods inherited from class java.lang.Object
finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- PI
  
  public static final double PI
  
  The value of PI.
  See Also:
  
  Constant Field Values
- HALF_PI
  
  public static final double HALF_PI
  
  The value of PI/2.
  See Also:
  
  Constant Field Values
- TWO_PI
  
  public static final double TWO_PI
  
  The value of 2 PI.
  See Also:
  
  Constant Field Values
- EPSLN
  
  public static final double EPSLN
  
  The epsilon value for checking if numbers are very close.
  See Also:
  
  Constant Field Values
- R2D
  
  public static final double R2D
  
  Conversion from radians to degrees.
  See Also:
  
  Constant Field Values
- C3P
  
  public static final double C3P
  
  A useless quirky companion constant to go along with R2D.
  See Also:
  
  Constant Field Values
- D2R
  
  public static final double D2R
  
  Conversion from degrees to radians.
  See Also:
  
  Constant Field Values
- falseEast
  
  protected double falseEast
  
  The false easting value.
- falseNorth
  
  protected double falseNorth
  
  The false northing value.
- ec
  
  protected double ec
  
  The eccentricity value for the spheroid.
- ec2
  
  protected double ec2
  
  The eccentricity value squared for the spheroid.
- rMajor
  
  protected double rMajor
  
  The semi-major axis in meters.
Constructor Details
- GCTPStyleProjection
  
  public GCTPStyleProjection(int system, int zone, double rMajor, double rMinor, int[] dimensions, AffineTransform affine) throws NoninvertibleTransformException
  
  Creates a GCTP style projection.
  
  Parameters:
  
  system - the map projection system.
  
  zone - the map projection zone for State Plane and UTM projections.
  
  rMajor - the semi-major axis in meters.
  
  rMinor - the semi-minor axis in meters.
  
  dimensions - the dimensions of the data grid as [rows, columns].
  
  affine - the affine transform for translating data [row, column] to map [x, y].
  
  Throws:
  
  NoninvertibleTransformException
Method Details
- setDatum
  
  protected void setDatum(Datum datum)
  
  Sets the datum for this projection and pre-computes values needed and matching spheroid code.
  
  Parameters:
  
  datum - the new datum to use.
- setFalse
  
  public void setFalse(double falseEast, double falseNorth)
  
  Sets the false east and north values. By default, these are both set to zero.
  
  Parameters:
  
  falseEast - the false easting value in meters.
  
  falseNorth - the false northing value in meters.
- asinz
  
  public static double asinz(double con)
  
  Computes asin and eliminates roundoff error.
  
  Parameters:
  
  con - the value to compute the arc sine for.
  
  Returns:
  
  the arc sine of the value, in the range of -pi/2 through pi/2.
- msfnz
  
  public static double msfnz(double eccent, double sinphi, double cosphi)
  
  Computes the constant small m which is the radius of a parallel of latitude, phi, divided by the semimajor axis.
  
  Parameters:
  
  eccent - the spheroid eccentricity.
  
  sinphi - sine of the latitude angle.
  
  cosphi - cosine of the latitude angle.
  
  Returns:
  
  the value m.
- qsfnz
  
  public static double qsfnz(double eccent, double sinphi, double cosphi)
  
  Computes the constant small q which is the radius of a parallel of latitude, phi, divided by the semimajor axis.
  
  Parameters:
  
  eccent - the spheroid eccentricity.
  
  sinphi - sine of the latitude angle.
  
  cosphi - cosine of the latitude angle.
  
  Returns:
  
  the value q.
- phi1z
  
  public static double phi1z(double eccent, double qs)
  
  Computes the value phi1, the latitude for the inverse of the Albers Conical Equal-Area projection.
  
  Parameters:
  
  eccent - the eccentricity angle in radians.
  
  qs - the angle in radians.
  
  Returns:
  
  the latitude angle in radians or Double.NaN if the iteration did not converge.
- phi2z
  
  public static double phi2z(double eccent, double ts)
  
  Computes the latitude angle, phi2, for the inverse of the Lambert Conformal Conic and Polar Stereographic projections.
  
  Parameters:
  
  eccent - the spheroid eccentricity.
  
  ts - the constant value t.
  
  Returns:
  
  the latitude angle in radians or Double.NaN if the iteration did not converge.
- phi3z
  
  public static double phi3z(double ml, double e0, double e1, double e2, double e3)
  
  Computes the latitude, phi3, for the inverse of the Equidistant Conic projection.
  
  Parameters:
  
  ml - the constant ml.
  
  e0 - the constant e0.
  
  e1 - the constant e1.
  
  e2 - the constant e2.
  
  e3 - the constant e3.
  
  Returns:
  
  the latitude angle in radians or Double.NaN if the iteration did not converge.
- phi4z
  
  public static double phi4z(double eccent, double e0, double e1, double e2, double e3, double a, double b, double[] c)
  
  Computes phi4, the latitude for the inverse of the Polyconic projection.
  
  Parameters:
  
  eccent - the eccentricity squared.
  
  e0 - the constant e0.
  
  e1 - the constant e1.
  
  e2 - the constant e0.
  
  e3 - the constant e0.
  
  a - the constant e0.
  
  b - the constant e0.
  
  c - the constant c (modified).
  
  Returns:
  
  the latitude angle in radians or Double.NaN if the iteration did not converge.
- pakcz
  
  public static double pakcz(double pak)
  
  Converts the 2 digit alternate packed DMS format (+/-)DDDMMSS.SSS to 3 digit standard packed DMS format (+/-)DDDMMMSSS.SSS.
  
  Parameters:
  
  pak - the angle in alternate packed DMS format.
  
  Returns:
  
  the angle packed in 3 digit format.
- pakr2dm
  
  public static double pakr2dm(double pak)
  
  Converts radians to 3 digit packed DMS format (+/-)DDDMMMSSS.SSS.
  
  Parameters:
  
  pak - the angle in radians.
  
  Returns:
  
  the angle packed in 3 digits format.
- e0fn
  
  public static double e0fn(double x)
  
  Computes the constant e0 which is used in a series for calculating the distance along a meridian.
  
  Parameters:
  
  x - the eccentricity squared.
  
  Returns:
  
  the constant e0.
- e1fn
  
  public static double e1fn(double x)
  
  Computes the constant e1 which is used in a series for calculating the distance along a meridian.
  
  Parameters:
  
  x - the eccentricity squared.
  
  Returns:
  
  the constant e1.
- e2fn
  
  public static double e2fn(double x)
  
  Computes the constant e2 which is used in a series for calculating the distance along a meridian.
  
  Parameters:
  
  x - the eccentricity squared.
  
  Returns:
  
  the constant e2.
- e3fn
  
  public static double e3fn(double x)
  
  Computes the constant e3 which is used in a series for calculating the distance along a meridian.
  
  Parameters:
  
  x - the eccentricity squared.
  
  Returns:
  
  the constant e3.
- e4fn
  
  public static double e4fn(double x)
  
  Computes the constant e4 used in the Polar Stereographic projection.
  
  Parameters:
  
  x - the eccentricity.
  
  Returns:
  
  the constant e4.
- mlfn
  
  public static double mlfn(double e0, double e1, double e2, double e3, double phi)
  
  Computes the value of M which is the distance along a meridian from the Equator to latitude phi.
  
  Parameters:
  
  e0 - the constant e0.
  
  e1 - the constant e1.
  
  e2 - the constant e0.
  
  e3 - the constant e0.
  
  phi - the latitude value in radians.
  
  Returns:
  
  the distance value M.
- calc_utm_zone
  
  public static int calc_utm_zone(double lon)
  
  Calculates the UTM zone number.
  
  Parameters:
  
  lon - the longitude in degrees.
  
  Returns:
  
  the UTM zone number.
- sign
  
  public static int sign(double x)
  
  Gets the sign of a value.
  
  Parameters:
  
  x - the value to get the sign for.
  
  Returns:
  
  the sign of the value, -1 if the value is less than zero, or 1 otherwise.
- tsfnz
  
  public static double tsfnz(double eccent, double phi, double sinphi)
  
  Computes the constant small t for use in the forward computations in the Lambert Conformal Conic and the Polar Stereographic projections.
  
  Parameters:
  
  eccent - the eccentricity of the spheroid.
  
  phi - the latitude phi in radians.
  
  sinphi - the sine of the latitude.
  
  Returns:
  
  the contant term t.
- adjust_lon
  
  public static double adjust_lon(double x)
  
  Adjusts a longitude angle to be in the range [-180 .. 180] in radians.
  
  Parameters:
  
  x - the input longitude in radians.
  
  Returns:
  
  the adjusted longitude in radians.
- sphdz
  
  public static void sphdz(int isph, double[] parm, double[] r_major, double[] r_minor, double[] radius)
  Gets the semi-major, semi-minor, and radius axes lengths based on the parameters and spheroid code. The following algorithm is used. If the spheroid code is negative, the first two values in the parameter array parm are used to define the values as follows:
  
  If parm[0] is a non-zero value and parm[1] is greater than one, the semimajor axis and radius are set to parm[0] and the semiminor axis is set to parm[1].
  
  If parm[0] is nonzero and parm[1] is greater than zero but less than or equal to one, the semimajor axis and radius are set to parm[0] and the semiminor axis is computed from the eccentricity squared value parm[1]. This algorithm is given below.
  
  If parm[0] is nonzero and parm[1] is equal to zero, the semimajor axis, radius, and semiminor axis are set to parm[0].
  
  If parm[0] equals zero and parm[1] is greater than zero, the default Clarke 1866 is used to assign values to the semimajor axis, radius and semiminor axis.
  
  If parm[0] and parm[1] equals zero, the semimajor axis and radius are set to 6370997.0 and the semiminor axis is set to zero.
  
  If a spheroid code is zero or greater, the semimajor and semiminor axis are defined by the spheroid code arrays in the SpheroidConstants interface, and the radius is set to 6370997.0. If the spheroid code is greater than MAX_SPHEROIDS-1 the default spheroid, Clarke 1866, is used to define the semimajor and semiminor axis and radius is set to 6370997.0.
  
  The algorithm to define the semiminor axis using the eccentricity squared value is as follows:
  
  semiminor = sqrt(1.0 - ES) * semimajor
  
  where ES is the eccentricity squared.
  Parameters:
  
  isph - the spheroid code number.
  
  parm - the projection parameter array.
  
  r_major - the semi-major axis value in meters (modified).
  
  r_minor - the semi-minor axis value in meters (modified).
  
  radius - the radius value in meters (modified).
- pack_angle
  
  public static double pack_angle(double angle)
  
  Packs an angle in degrees to DDDMMMSSS.SS format.
  
  Parameters:
  
  angle - the angle in degrees.
  
  Returns:
  
  the packed angle in DDDMMMSSS.SS format.
- unpack_angle
  
  public static double unpack_angle(double angle)
  
  Unpacks an angle in DDDMMMSSS.SS format to degrees.
  
  Parameters:
  
  angle - the packed angle in DDDMMMSSS.SS format.
  
  Returns:
  
  the angle in degrees.

Class GCTPStyleProjection

Field Summary

Fields inherited from class noaa.coastwatch.util.trans.MapProjection

Fields inherited from class noaa.coastwatch.util.trans.EarthTransform

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

Constructor Summary

Method Summary

Methods inherited from class noaa.coastwatch.util.trans.MapProjection

Methods inherited from class noaa.coastwatch.util.trans.EarthTransform2D

Methods inherited from class noaa.coastwatch.util.trans.EarthTransform

Methods inherited from class noaa.coastwatch.util.MetadataContainer

Methods inherited from class java.lang.Object

Field Details

PI

HALF_PI

TWO_PI

EPSLN

R2D

C3P

D2R

falseEast

falseNorth

ec

ec2

rMajor

Constructor Details

GCTPStyleProjection

Method Details

setDatum

setFalse

asinz

msfnz

qsfnz

phi1z

phi2z

phi3z

phi4z

pakcz

pakr2dm

e0fn

e1fn

e2fn

e3fn

e4fn

mlfn

calc_utm_zone

sign

tsfnz

adjust_lon

sphdz

pack_angle

unpack_angle