at 906 in the current example the set of hypotheses 526 532 536 540 and 548 may be augmented with hypothesis 544 at 910 an augmented navigation solution is computed from the augmented hypotheses set at 912 if the grid selected at 904 has multiple identified hypotheses another hypothesis is selected at 914 and processing returns 908 in fig8 hypothesis 546 may be selected at 914 when all identified hypotheses of the selected grid have been processed processing proceeds from 912 to 916 at 916 the augmented navigation solution computed at 910 and any additional augmented navigation solutions computed in subsequent iterations of 914 through 910 are evaluated at 918 evaluation results of the one or more augmented navigation solutions for grid selected at 904 are compared with evaluation results of the plausible navigation solution selected at 902 at 920 one navigation solution is retained from amongst the one or more augmented navigation solutions evaluated at 916 and the plausible navigation solution selected at 902 based on the comparison at 918 at 922 if multiple of the j grids are not represented in the k hypotheses plausible navigation solution selected at 902 another grid is selected at 924 and processing returns to 906 when all unrepresented grids of the navigation solution selected at 902 have been processed processing proceeds from 922 to 926 at 926 where there are multiple k hypotheses based navigation solutions another plausible k hypotheses based navigation solution is selected at 928 and processing returns to 904 when all k hypotheses based navigation solutions have been processed processing proceeds from 926 to 930 at 930 a most plausible navigation may.