Raw measurements for a plurality of GNSS satellites are pruned based on signal to noise ratio (SNR) and elevation; with remaining unpruned raw measurements sorted by SNR into a sorted list of raw measurements. A first dilution of precision (DOP) based selecting process is performed to select an initial candidate list of raw measurements. The first DOP selecting process begins by using at least those of said pruned list of raw measurements which exceed an SNR quality threshold. The initial candidate list of raw measurements is sorted by elevation angle. A second DOP selecting process is performed to select a final candidate list of raw measurements. The second DOP selecting process begins by using at least those of the sorted initial candidate list which an elevation quality threshold. The final candidate list is used in position computation for a present epoch.