Package org.apache.sis.referencing.operation.projection

Class ObliqueMercator

java.lang.Object
org.apache.sis.io.wkt.FormattableObject
org.apache.sis.referencing.operation.transform.AbstractMathTransform
org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
org.apache.sis.referencing.operation.projection.NormalizedProjection
org.apache.sis.referencing.operation.projection.ConformalProjection
org.apache.sis.referencing.operation.projection.ObliqueMercator
All Implemented Interfaces:
Serializable, Parameterized, LenientComparable, org.opengis.referencing.operation.MathTransform, org.opengis.referencing.operation.MathTransform2D
public class ObliqueMercator extends ConformalProjection
Oblique Mercator projection (EPSG codes 9812, 9815). The Oblique Mercator projection can be seen as a generalization of Mercator and TransverseMercator projections when the central line is not along the equator or a meridian, respectively. This class covers also the Rectified Skew Orthomorphic (RSO) case.

There is different ways to specify the projection parameters:

  • Variant A (EPSG:9812) uses false easting/northing defined at the natural origin of the coordinate system.
  • Variant B (EPSG:9815) uses false easting/northing defined at the projection center.
  • ESRI "Two Points" variant defines the central line with two points instead of with an azimuth angle.
Azimuth values of 0 and ±90 degrees are allowed, but for such cases the Mercator and TransverseMercator projections should be preferred, both for performance and accuracy reasons.
Since:
1.0
Version:
1.2
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      For compatibility with different versions during deserialization.
      See Also:

    • B

      private final double B
      Constants used in the transformation. Those coefficients depend only on the latitude of center.

    • H

      private final double H
      Constants used in the transformation. Those coefficients depend only on the latitude of center.

    • sinγ0

      private final double sinγ0
      Sine and Cosine values for γ0 (the angle between the meridian and central line at the intersection between the central line and the Earth equator on aposphere).

    • cosγ0

      private final double cosγ0
      Sine and Cosine values for γ0 (the angle between the meridian and central line at the intersection between the central line and the Earth equator on aposphere).

  • Constructor Details

    • ObliqueMercator

      public ObliqueMercator(org.opengis.referencing.operation.OperationMethod method, Parameters parameters)
      Creates an Oblique Mercator projection from the given parameters. The method argument can be the description of one of the following:
      • "Hotine Oblique Mercator (variant A)".
      • "Hotine Oblique Mercator (variant B)".
      • "Hotine Oblique Mercator two point center" (from ESRI).
      • "Hotine Oblique Mercator two point natural origin" (from ESRI).
      • "Rectified Skew Orthomorphic".
      Parameters:
      method - description of the projection parameters.
      parameters - the parameter values of the projection to create.

    • ObliqueMercator

      private ObliqueMercator(Initializer initializer)
      Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").

  • Method Details

    • initializer

      @Workaround(library="JDK", version="1.7") private static Initializer initializer(org.opengis.referencing.operation.OperationMethod method, Parameters parameters)
      Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").

    • getInternalParameterNames

      final String[] getInternalParameterNames()
      Returns the names of additional internal parameters which need to be taken in account when comparing two ObliqueMercator projections or formatting them in debug mode.
      Overrides:
      getInternalParameterNames in class NormalizedProjection

    • getInternalParameterValues

      final double[] getInternalParameterValues()
      Returns the values of additional internal parameters which need to be taken in account when comparing two ObliqueMercator projections or formatting them in debug mode.
      Overrides:
      getInternalParameterValues in class NormalizedProjection

    • γ0

      private double γ0()
      Returns the value used for computing sinγ0 and cosγ0. We did not stored that value because it is not used often.

    • transform

      public org.opengis.referencing.operation.Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException
      Projects the specified (λ,φ) coordinates (units in radians) and stores the result in dstPts. In addition, opportunistically computes the projection derivative if derivate is true. The results must be multiplied by the denormalization matrix before to get linear distances.
      Specified by:
      transform in class NormalizedProjection
      Parameters:
      srcPts - the array containing the source point coordinates, as (longitude, latitude) angles in radians.
      srcOff - the offset of the single coordinate tuple to be converted in the source array.
      dstPts - the array into which the converted coordinates is returned (may be the same than srcPts). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.
      dstOff - the offset of the location of the converted coordinates that is stored in the destination array.
      derivate - true for computing the derivative, or false if not needed.
      Returns:
      the matrix of the projection derivative at the given source position, or null if the derivate argument is false.
      Throws:
      ProjectionException - if the coordinates cannot be converted.
      See Also:

    • inverseTransform

      protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException
      Converts the specified (x,y) coordinates and stores the result in dstPts (angles in radians).
      Specified by:
      inverseTransform in class NormalizedProjection
      Parameters:
      srcPts - the array containing the source point coordinates, as linear distance on a unit sphere or ellipse.
      srcOff - the offset of the point to be converted in the source array.
      dstPts - the array into which the converted point coordinates is returned (may be the same than srcPts). Coordinates will be (longitude, latitude) angles in radians.
      dstOff - the offset of the location of the converted point that is stored in the destination array.
      Throws:
      ProjectionException - if the point cannot be converted.