Ambiguity reduction using spatial variation for two dimensional navigation

Many continuous wave navigational systems are not capable of independently resolving the integer number of wavelengths in a range measurement; the range is said to be ambiguous. The fractional part of the range can be measured but the integer must be initially given, and then tracked. If the number of ranges required to triangulate a fix exceeds the minimum, and if the mobile presents spatial variability, the solutions will ´focus´ at the correct position which in turn yields the appropriate integer for each range. This paper addresses an algorithm, the ambiguity reduction process (ARP), which eliminates the ambiguous solution for a two-dimensional navigation system.