With two fixed target locations, the Sonin electronic measuring device enables stem mapping of forest plots and transects to be done efficiently by one person, or greatly accelerates team work. There is no cumulative mapping error within individual plots. Measurements are much faster than tape measuring and more accurate than bearing/range methods, and the equipment costs are very low. The procedures for data verification, conversion to Cartesian coordinates, and for standarization of interplot coordinates are presented. South. J. Appl. For. 18(3):133-136.