Method for reducing position uncertainty of a portable inertial navigation device
AssigneeMotorola, Inc.
InventorsCharles B. Swope, Chet A. Lampert
Life of this patent
Estimating the term…
Abstract
A first set of coordinates (100) of a device and an estimated positional error (“EPE”) radius (102) is measured. An EPE circle (104) is derived, in which the device is approximately located, from the first set of coordinates (100) and the EPE radius (102). When it is determined that the EPE radius (102) exceeds a predetermined threshold, a first range (106) between the device and a ranging site (108) is measured, and a locus of points (110) on and within the EPE circle (104) is determined, wherein a distance between the ranging site (108) and each point in the locus of points (110) approximately equals the first range (106).
Claims20
A method comprising the steps of:
- measuring a first set of coordinates of a device;
- measuring an estimated positional error (“EPE”) radius for the first set of coordinates;
- deriving an EPE circle, in which the device is approximately located, from the first set of coordinates and the EPE radius;
- determining that the EPE radius exceeds a predetermined threshold;
- measuring a first range between the device and a ranging site;
- and
- determining a locus of points within the EPE circle, wherein a distance between the ranging site and each point in the locus of points approximately equals the first range.
A method comprising the steps of:
- measuring a first set of coordinates of a device;
- measuring a estimated positional error (“EPE”) radius for the first set of coordinates;
- deriving a EPE sphere, in which the device is approximately located, from the first set of coordinates and the EPE radius;
- determining that the EPE radius exceeds a predetermined threshold;
- measuring a first range between the device and a ranging site;
- and
- determining a locus of points within the EPE sphere, wherein a distance between the ranging site and each point in the locus of points approximately equals the first range.
Dependencies are inferred from the claim text.