Class HelmertTransformation

  • All Implemented Interfaces:
    Serializable, TransformProvider

    public class HelmertTransformation
    extends Object
    implements TransformProvider
    Transformation class for geodetic systems.

    The Helmert transformation is mainly used to convert between various realizations of geodetic frames, for example in the ITRF family.

    The original Helmert transformation is a 14 parameters transform that includes translation, velocity, rotation, rotation rate and scale factor. The scale factor is useful for coordinates near Earth surface, but it cannot be extended to outer space as it would correspond to a non-unitary transform. Therefore, the scale factor is not used here.

    Instances of this class are guaranteed to be immutable.

    Since:
    5.1
    Author:
    Luc Maisonobe
    See Also:
    Serialized Form
    • Constructor Detail

      • HelmertTransformation

        public HelmertTransformation​(AbsoluteDate epoch,
                                     double t1,
                                     double t2,
                                     double t3,
                                     double r1,
                                     double r2,
                                     double r3,
                                     double t1Dot,
                                     double t2Dot,
                                     double t3Dot,
                                     double r1Dot,
                                     double r2Dot,
                                     double r3Dot)
        Build a transform from its primitive operations.
        Parameters:
        epoch - reference epoch of the transform
        t1 - translation parameter along X axis (BEWARE, this is in mm)
        t2 - translation parameter along Y axis (BEWARE, this is in mm)
        t3 - translation parameter along Z axis (BEWARE, this is in mm)
        r1 - rotation parameter around X axis (BEWARE, this is in mas)
        r2 - rotation parameter around Y axis (BEWARE, this is in mas)
        r3 - rotation parameter around Z axis (BEWARE, this is in mas)
        t1Dot - rate of translation parameter along X axis (BEWARE, this is in mm/y)
        t2Dot - rate of translation parameter along Y axis (BEWARE, this is in mm/y)
        t3Dot - rate of translation parameter along Z axis (BEWARE, this is in mm/y)
        r1Dot - rate of rotation parameter around X axis (BEWARE, this is in mas/y)
        r2Dot - rate of rotation parameter around Y axis (BEWARE, this is in mas/y)
        r3Dot - rate of rotation parameter around Z axis (BEWARE, this is in mas/y)
    • Method Detail

      • getEpoch

        public AbsoluteDate getEpoch()
        Get the reference epoch of the transform.
        Returns:
        reference epoch of the transform