US Patent 7983694 Target and base station for a navigation system

The present invention relates to a method of determining the location of a target. The method includes initializing a set of base stations to determine their location relative to each other. At the target, the time of arrival of at least one signal from each of the plurality of base stations is measured. From this, the location of the target relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.