Project Helen Enander Abstract Digital Elevation Models are widely used in modeling applications.
Errors can limit the usefulness of the data.
Two spatial and three frequency filtering techniques were compared in an effort to reduce periodic and random errors. The spatial filters either reduced only one type of noise or made large changes in the data. The Fast Fourier Transform filtering techniques appeared to reduce periodic errors without large changes in the information content of the data, and one method seemed to reduce random errors as well. A limitation to the usefulness of DEMs is errors in the data. Level II DEMs are now produced by the last method, but Level I DEMs, which are used in this project, could have been produced by the other methods.