Accuracy Assessment of Spatial Distribution of Lab Characterization Data for Indiana.

Between 1965 and 1990, Purdue University participated in the accelerated soil survey program for the state of Indiana and conducted chemical data analysis on 1060 soil profiles. The original records available at Purdue include the legal land description based on the Public Land Survey System (PLSS). In most cases, the sample locations are probably accurate to within about fifty feet of the actual location. This database was eventually transferred to the Natural Resources Conservation Service (NRCS) for inclusion in the National Soil Information System (NASIS). During the transfer, a computer program was used to parse the legal land descriptions and assign geographic coordinates to the sample points. It was known at the time that the geographic coordinates generated by this program were only approximate. Estimates are that they may be in error by several hundred feet. The objective of this project will be to develop a procedure to update the geographic coordinates so that they are as accurate as possible within the limits of the legal land description system used at the time the soils were sampled.