Package org.geotools.referencing.operation.builder

Class BursaWolfTransformBuilder

Object
MathTransformBuilder
BursaWolfTransformBuilder
public class BursaWolfTransformBuilder extends MathTransformBuilder
Builds MathTransform setup as BursaWolf transformation from a list of MappedPosition. The calculation uses least square method. Calculated parameters can be used for following operations:

The equations: 

 X = q * R * x  +  T ,
Where X is the Matrix of destination points, q is the scale, R is the rotation Matrix, x is the Matrix of source points and T is matrix of translation. Expressing the errors, we get this: 
        Err =  A * Dx + l
where Err is the Error Matrix, A is Matrix of derivations, Dx is Matrix of difference changes of 7 parameters, and l is value of DX, DY, DZ for calculated from approximate values. Using the least square method to minimalize the errors we get this result: 
  Dx = (ATA)-1 ATl
Since:
2.4
Author:
Jan Jezek

  • Constructor Details

    • BursaWolfTransformBuilder

      public BursaWolfTransformBuilder(List<MappedPosition> vectors)
      Creates a BursaWolfTransformBuilder.
      Parameters:
      vectors - list of mapped positions.

  • Method Details

    • getMinimumPointCount

      public int getMinimumPointCount()
      Returns the minimum number of points required by this builder, which is 3.
      Specified by:
      getMinimumPointCount in class MathTransformBuilder
      Returns:
      the minimum number of points required by this builder which is 3.

    • getDimension

      public int getDimension()
      Returns the dimension for source and target CRS, which is 2.
      Overrides:
      getDimension in class MathTransformBuilder
      Returns:
      dimension for source and target CRS, which is 2.

    • getCoordinateSystemType

      public Class<? extends CartesianCS> getCoordinateSystemType()
      Returns the required coordinate system type, which is cartesian CS.
      Overrides:
      getCoordinateSystemType in class MathTransformBuilder
      Returns:
      coordinate system type

    • getx

      protected GeneralMatrix getx()
      Fills the x matrix by coordinates of source points.
      Returns:
      x matrix.

    • getX

      protected GeneralMatrix getX()
      Fills the x matrix by coordinates of destination points.
      Returns:
      the X matrix

    • getRalfa

      protected GeneralMatrix getRalfa()
      Generates rotation matrix around X axis.
      Returns:
      rotation Matrix

    • getRbeta

      protected GeneralMatrix getRbeta()
      Generates rotation matrix around Y axis.
      Returns:
      rotation Matrix.

    • getRgamma

      protected GeneralMatrix getRgamma()
      Generates rotation matrix around Z axis.
      Returns:
      rotation Matrix.

    • getDRalfa

      protected GeneralMatrix getDRalfa()
      Generates partial derivative with respect to alfa.
      Returns:
      Matrix, that represents partial derivation of rotation Matrix with respect to alfa.

    • getDRbeta

      protected GeneralMatrix getDRbeta()
      Generates partial derivative with respect to beta.
      Returns:
      Matrix, that represents partial derivation of rotation Matrix with respect to beta.

    • getDRgamma

      protected GeneralMatrix getDRgamma()
      Generates partial derivative with respect to gamma.
      Returns:
      Matrix, that represents partial derivation of rotation Matrix with respect to gamma.

    • getDq

      protected GeneralMatrix getDq()
      Generates partial derivative in q (scale factor).
      Returns:
      rotation Matrix.

    • getl

      protected GeneralMatrix getl()
      Calculates the matrix of errors from aproximate values of prameters.
      Returns:
      the l matrix.

    • specialMul

      protected GeneralMatrix specialMul(GeneralMatrix R, GeneralMatrix x)
      Method for multiplying matrix (3,3) by matrix of coordintes (3 number of coordinates,1)
      Parameters:
      R - ratrix
      x - matrix
      Returns:
      matrix

    • getA

      protected GeneralMatrix getA()
      Glues the submatrix of derivations into the A matrix.
      Returns:
      A mtarix

    • getParameters

      protected double[] getParameters()
      Returns array of doubles of transformation parameters (dx, dy, dz, ex, ey, ez, scale).
      Returns:
      array of doubles of transformation parameters (dx, dy, dz, ex, ey, ez, scale).

    • getDxMatrix

      public GeneralMatrix getDxMatrix()
      Method that claculates the parameters by iteration. The tolarance is set to 1 10-8 and max �number of steps is set to 20.
      Returns:
      Matrix of parameters (dx, dy, dz, ex, ey, ez, scale).

    • getBursaWolfParameters

      public BursaWolfParameters getBursaWolfParameters(GeodeticDatum Datum)
      Returns Bursa Wolf Transformation parameters.
      Parameters:
      Datum - The target datum for this parameters.
      Returns:
      parameters the BursaWolfParameters

    • setTargetGeodeticDatum

      public void setTargetGeodeticDatum(GeodeticDatum gd)

    • computeMathTransform

      protected MathTransform computeMathTransform() throws FactoryException
      Returns MathtTransform setup as BursaWolf transformation.
      Specified by:
      computeMathTransform in class MathTransformBuilder
      Returns:
      calculated MathTransform
      Throws:
      FactoryException - when the size of source and destination point is not the same or if the number of points is too small to define such transformation.