Systematic geographic sampling with UTM coordinates

Abstract A geographic sampling method that incorporates the advantages of systematic sampling while preserving randomness is described. The method, stratified systematic unaligned sampling, is suited to both random surveys of any size area and systematic coverage of large areas such as might be required when mapping fallout patterns or determining land use for environmental impact studies. In our application, the Universal Transverse Mercator (UTM) grid coordinate system is used. The UTM grid system is well suited to this sampling method because of its rectangular nature, decimal basis, universal nature, and relative ease of use for determining grid coordinates in the field from standard topographic maps. An application of this method to a statewide survey of indoor radon levels in Pennsylvania is described in detail.