System and Method for Position Determination Using Low Earth Orbit Satellites
AssigneeSkyBitz, Inc.
InventorsMichael Harvey, Craig Malone, Uday Shankar, Mike Walgren, Corwin Walker Young
Life of this patent
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Abstract
A system and method for position determination using low earth orbit satellites. A mobile terminal affixed to an asset initiates a collection of global positioning system satellite measurements (e.g., code phase) based on a hardware trigger generated by a low earth orbit satellite modem. Timing information reflective of the time of the hardware trigger pulse is transmitted to an operations center along with the global positioning system satellite measurements to enable the operations center to determine a position of the mobile terminal.
Claims19
A method for determining a location of a mobile terminal, comprising:
- receiving, via a low earth orbit satellite, a communication from a mobile terminal that includes timing information and measurements of a plurality of global positioning system satellite signals;
- determining a collection time of said global positioning system satellite measurements using said timing information;
- determining the coordinates of said low earth orbit satellite using said determined collection time;
- determining a low earth orbit satellite beam footprint based on said determined coordinates;
- identifying a set of initial candidate points within said determined low earth orbit satellite beam footprint;
- determining a set of candidate position solutions using said set of initial candidate points and said global positioning system satellite measurements;
- and
- determining a location of said mobile terminal based on said determined set of candidate position solutions.
A method in a mobile terminal affixed to an asset, comprising:
- generating, by a low earth orbit satellite modem in response to a global positioning system measurement collection request, a hardware trigger pulse;
- initiating, in response to said generated hardware trigger pulse, a collection of global positioning system measurements;
- and
- transmitting, by said low earth orbit satellite modem, a communication to an operations center that includes said global positioning system measurements and timing information indicative of a time of generation of said hardware trigger pulse, said communication enabling said operations center to determine a position of said mobile terminal.
A mobile terminal that enables a remote determination of a location of the mobile terminal, comprising:
- a global positioning system engine;
- a measurement system that receives assisting information from said global positioning system engine, said assisting information enabling said measurement system to reduce the number of global positioning system satellites that are searched, said measurement system taking measurements from signals produced by each of said reduced number of global positioning system satellites;
- and
- a satellite modem that forwards said measurements to a remote operations center via a low earth orbit satellite modem, said forwarded measurements being used by said remote operations center to calculate a location of the mobile terminal at the time of said measurements.
A method in an operation center for determining a location of a mobile terminal, comprising:
- receiving a communication from said mobile terminal via a low earth orbit satellite, said communication including a rough position estimate of said mobile terminal and a confidence indicator of said rough position estimate;
- determining whether said confidence indicator indicates that said rough position estimate is likely within a pre-defined distance from an actual position of said mobile terminal;
- if said confidence indicator indicates that said rough position estimate is likely within said pre-defined distance from said actual position of said mobile terminal, then performing a position calculation using only said rough position estimate as a candidate seed point;
- and
- if said confidence indicator indicates that said rough position estimate is not likely within said pre-defined distance from said actual position of said mobile terminal, then performing a position calculation on a plurality of candidate seed points located in a grid covering an area covered by a beam of said low earth orbit satellite.
A method in an operation center for determining a location of a mobile terminal, comprising:
- receiving a communication from said mobile terminal via a low earth orbit satellite, said communication including a rough position estimate of said mobile terminal, and measurements of a plurality of positioning satellite signals;
- determining positions of a plurality of positioning satellites in view of said mobile terminal based on said rough position estimate;
- discarding measurements of one or more of said plurality of measurements based on an angle of elevation consideration of one or more positioning satellites relative to said mobile terminal;
- and
- determining a position of said mobile terminal using measurements of said positioning satellites that have not been discarded.
Dependencies are inferred from the claim text.