Estimation of Error and Compliance in Surveys by Kriging

This paper demonstrates how a geostatistical method called kriging can be used to establish limits on the minimum allowable contour interval (MACI) that complies with National Map Accuracy Standards (NMAS). Kriging works with the same survey point file as ordinarily required by a digital terrain model in a conventional mapping assignment, but extracts more information from the data set. The method is not appropriate for surveys of man-made features, but it is well suited for large surveys of predeveloped parcels and GIS base mapping. Because field surveys are nonrandom samples by design, kriging is unable to calculate a precise compliance contour. However, a suitably narrow interval for the MACI can be determined. Although kriging is not as definitive as a second independent survey, it can offer an effective, expedient, and inexpensive screening tool for assessing NMAS compliance. A detailed example demonstrates application of the proposed kriging method.