Abstract: A terrestrial based positioning system includes a plurality of location anchors configured to transmit and receive ultra-wide band (“UWB”) signals. In another aspect, a location tag configured to transmit and receive UWB signals uses signals transmitted by location anchors to determine its current position. In some implementations, a location tag may use Global Positioning System (“GPS”) signals or a combination of UWB and GPS signals to determine a current location. The location anchors are organized into zones used by the locations tags to determine a current position based in UWB signals. In some implementations, the locations anchors automatically create the necessary zones. Location anchors may also automatically determine the position of other location anchors. In yet other implementations, the location anchors relay data transmitted by a location tag. In addition, a location anchor may transmit GPS signals that can be used by standard GPS receivers.