Patent ID: 8427367

Claim:
A method within a GNSS receiver of selecting raw measurements for use by said GNSS receiver in position computation, said method comprising: accessing raw measurements for a plurality of GNSS satellites; pruning those of said accessed raw measurements which are below a preset absolute minimum signal to noise ratio (SNR) threshold to achieve a first pruned list of raw measurements; pruning those of first pruned list of raw measurements which are below a preset absolute minimum satellite elevation threshold to achieve a second pruned list of raw measurements; sorting said second pruned list of raw measurements by SNR to achieve a sorted list of raw measurements; performing first selecting process to achieve an initial candidate list of raw measurements, wherein said first selecting process involves selecting from said sorted list an incrementally increased plurality of raw measurements from best to worst SNR until a preset dilution of precision (DOP) quality threshold is met or said sorted list of raw measurements is exhausted, and wherein said first selecting process begins by using at least those of said sorted list of raw measurements which have a SNR value greater than a preset SNR quality threshold; sorting said initial candidate list of raw measurements by elevation angle to achieve a sorted initial candidate list of raw measurements; and performing a second selecting process to achieve a final candidate list of raw measurements, wherein said second selecting process involves selecting from said sorted initial candidate list an incrementally increased plurality of said raw measurements from highest to lowest elevation until said preset DOP quality threshold is met or said sorted initial candidate list of raw measurements is exhausted, and wherein said second selecting process begins by using at least those of said sorted initial candidate list of raw measurements which have an elevation value greater than a preset elevation quality threshold.