Trimble Navigation Limited

Scott R Smith

Gary R Lennen

Peter Leroy Froeberg

Vivek Nadkarni

James Sotelo

A method for substituting at least one high quality position measurement of an object taken before an interrupting event with a set of upgraded low quality position measurements of the object provided by the same source of measurements after the interrupting event. The method comprises the following steps: (A) obtaining at least one high quality position measurement of the object provided by a source of measurements before the interrupting event; (B) saving at least one high quality position measurement of the object; (C) if at least one position measurement of the object provided by source of measurements after the interrupting event is of substantially high quality, using at least one position measurement of substantially high quality of the object for navigation purposes of the object; and (D) if each position measurement of the object provided by the source of measurements after the interrupting event is of low quality, and if there is not at least one restoration event; then upgrading at least one position measurement of the object by using an upgrade algorithm.

Method for substituting at least one high quality position measurement taken before an interrupting event with a set of upgraded low quality position measurements provided by the same source of measurements after the interrupting event

A method and apparatus for processing multipath reflection effects in timing systems is disclosed in which a determination is made of whether a received signal is a reflected signal. A detector provides from an input signal a pair of signals representative of whether the input signal contained right-hand circularly polarized and left-hand circularly polarized components. The representative signals are separately processed in synchronized logic circuits to determine relative power levels. The power levels are compared to determine the nature of the dominant polarization of the input signal.

Method and apparatus for processing multipath reflection effects in timing systems

Method and apparatus for processing multipath reflection effects in

A system and method for determining which of a plurality of travel paths is taken by vehicles through area in which the performance of an automatic vehicle location (AVL) system is reduced. In one embodiment, the present invention divides a geographic region into a plurality of signature zones which are further divided into a plurality of signature zone cells. The signature zone cells in each signature zone correspond to travel paths that pass through an area having structures that prevent reception of GPS signals or any area where GPS alone is not sufficient to discern travel path. The present automatic vehicle path determination system then calculates correlation values for positions in each signature zone cell that correspond to the travel paths that pass through the signature zone. The position of each vehicles is monitored by an automatic vehicle location (AVL) system. The present automatic vehicle path determination system then determines the path taken by each vehicle passing through the signature zone. The present invention then communicates to the CAD system the path taken by each vehicle. Thus, the present invention provides a system which automatically determines which path is taken by a vehicle entering an area having structures that prevent reception of GPS signals, a system which can function in conjunction with an existing AVL or CAD system, and a system which reduces CAD system operator decision making processes.

Growing community of inventors

Scotts Valley, CA, United States of America

Scott R Smith