1. A method for determining a location of an underground object during a digging operation, including the steps of: delivering a signal toward the underground object; receiving a reflected signal from the underground object; determining an initial location of the underground object; creating a region of uncertainty around the underground object as a function of a level of confidence of the determined initial location; performing at least one process to improve the level of confidence; and adjusting the region of uncertainty as a function of the improved level of confidence.