Selecting raw measurements for use in position computation
First Claim
1. 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.
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Accused Products
Abstract
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.
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Citations
30 Claims
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1. A method within a GNSS receiver of selecting raw measurements for use by said GNSS receiver in position computation, said method comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A non-transitory computer readable storage medium having computer executable instructions stored thereon which, when executed cause a computer system to perform a method of selecting raw measurements for use by a global navigation satellite system (GNSS) receiver in position computation, said method comprising:
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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 said 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; and performing a 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 first 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. - View Dependent Claims (17, 18, 19, 20)
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21. A non-transitory computer readable storage medium having computer executable instructions stored thereon which, when executed cause a computer system to perform a method of selecting raw measurements for use by a global navigation satellite system (GNSS) receiver in position computation, said method comprising:
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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 said 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 elevation angle to achieve a sorted list of raw measurements; and performing a 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 highest to lowest elevation until a first 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 an elevation value greater than a preset elevation quality threshold. - View Dependent Claims (22, 23, 24, 25)
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26. A global navigation satellite system (GNSS) position determination system comprising:
an automated raw measurement selector module configured for automatically adjusting mask settings in order to select a final candidate list of raw measurements, from available raw measurements, in order to obtain the best quality position solution possible from a set of satellite measurements, wherein said automated raw measurement selector module comprises a plurality of preset thresholds used in determination of said final candidate list of raw measurements, and said plurality of preset thresholds include; a preset absolute minimum signal-to-noise ratio (SNR) threshold; a preset absolute minimum elevation threshold; a preset SNR quality threshold set at a separate level from said absolute minimum SNR threshold; a preset elevation quality threshold set at a separate level from said absolute minimum elevation threshold; and at least one preset dilution of precision (DOP) threshold. - View Dependent Claims (27, 28, 29, 30)
Specification