Lecture Notes for Clarke, K. C. Analytical and Computer Cartography

Lecture 14: Terrain Analysis I


3D Transformations


Interpolation to a Grid


Weighting Methods


Inverse Distance Weighting

inverse_d

  1. Assigns points to cells
  2. Averages multiples
  3. for all unfilled cells
  4. search outward using an increasingly large square neighborhood
  5. until at least npts are found
  6. apply inverse distance weighting

Has been parallelized (and found highly efficient) by Armstrong


Trend Projection Methods


Search Patterns


Kriging


Alternative Methods


Surface-Specific Point Sampling

Terrain "Skeleton"

Wedding Cake effect

Specific problem when grids are made from contours (e.g. 3 arc second DEMs)


Keith Clarke Last Change 5/19/97 Copyright Prentice Hall, 1995