US 2002/0154056 A1 · Method and apparatus providing improved postion estimate based on an initial coarse postion estimate

Abstract

Techniques for determining the location of a device based on an initial coarse position estimate for the device, which is derived based on initial (less accurate) estimates of the position of a plurality of transmitters. In one method, the coarse position estimate for the device and revised (more accurate) position estimates for the transmitters are received. A revised position estimate for the device is initialized (e.g., to the coarse position estimate). An update vector is next computed based on the initial and revised position estimates for the device and the initial and revised position estimates for the transmitters. The revised position estimate for the device is then updated based on the update vector. The computation for the update vector and the updating of the revised position estimate for the device can be repeated a number of times to achieve a more and more accurate estimate.

Claims20

Dependent claims

A method for determining the location of a device, comprising:

(a) receiving an estimate of the location of the device, the estimate having been calculated using initial estimates of the position of a plurality of transmitters;
(b) calculating a set of range estimates using a revised estimate of the position of the device and revised estimates of the positions of the transmitters;
(c) deriving an intermediate position estimate for the device based on the set of measurements and the initial position estimates for the transmitters;
(d) computing an update vector based in part on the intermediate and revised position estimates for the device;
and
(e) updating the revised position estimate for the device based on the update vector.

3 more elements

A position identifying device comprising:

(a) a communication port configured to receive a coarse position estimate for a receiver device derived based in part on initial estimates of the position of a plurality of transmitters;
and
(b) a processor operatively coupled to the communication port and configured to:
(i) receive information indicative of revised position estimates for the transmitters,
(ii) initialize a revised position estimate for the receiver device,
(iii) compute an update vector based on the initial and revised position estimates for the receiver device and the initial and revised position estimates for the transmitters,
(iv) update the revised position estimate for the receiver device based on the update vector, and
(v) repeat the compute and update a plurality of times.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus providing improved postion estimate based on an initial coarse postion estimate

Life of this patent

Method and apparatus providing improved postion estimate based on an initial coarse postion estimate

Life of this patent

Abstract

Claims20