7.B.iv. Summary: How to Use These Assessments

If you are developing critical applications, the accuracy figures estimated here should only be a starting point for your own assessments. For example, areas of rugged topography can be expected to have different (probably coarser) absolute and relative accuracies than areas of subdued topography. Also, mixtures of map and imagery scales (and types) may have been used in developing some DEMs. In the United States, for example, areas in the mountainous West may have contour intervals of about 60m (200ft), whereas in parts of North Dakota, 2m (5ft) supplemental contours exist in places. The figures in Table 2 (Section 7.B.ii) are an attempt to provide information, and are certainly not a commitment to such levels of accuracy anywhere in the data base.