Spherekit: Interpolate

Interpolate to:

Grid (regularly spaced set of points)
Enter the latitude and longitude of the northwest corner of the grid. Also enter the grid spacing in degrees or km. For grid spacings in km, the entered value represents the north-south spacing; east-west spacing is less at latitudes other than the equator. The grid can be masked to exclude sites over the ocea and other water bodies or can be masked to exclude land sites.

Network (irregularly spaced set of points)
Enter the file name containing the network locations.

In a future version of Spherekit, interpolation may be to a set of polygons (irregular areas)

Interpolation methods

All of the interpolation algorithms in Spherekit take account of the sphericity of the earth. Thus, distances between points are computed as great circle distances. Most conventional algorithms are planar algorithms, and require the earth to be projected to a plane prior to interpolation.

Five classes of interpolation algorithms are available in Spherekit:

  • Inverse distance weighting
  • Triangulation
  • Kriging
  • Multiquadric
  • Thin plate spline

    Begin Interpolation

    Selection of this option initiates the interpolation. A check is performed to ensure that a method and grid/network have been chosen.

    NCGIA 1997