Apparatus and method for obtaining geographical positional data for an object located underground

摘要

Geographical positional data is obtained for an underground object by locating the object using a device that locates underground objects. An apparatus that receives data from a global position system ("GPS") provides data identifying global position of the device, and thus also of the located underground object. A data storage unit stores such positional data, which may be used in the future to re-locate the underground object. The GPS-data receiving apparatus can preferably receive data from at least one overhead GPS satellite and from a secondary stationary receiver. Data from the secondary stationary receiver may be modulated on to a signal transmitted along a detected underground cable object.