Trx Systems, Inc.

John Riley Miller

Carole Teolis

Benjamin E Funk

John George Karvounis

Jared Napora

Dan Hakim

Travis Young

A method for computing a correction to a compass heading for a portable device worn or carried by a user is described. The method involves determining a heading for the device based on a compass reading, collecting data from one or more sensors, determining if the device is indoors or outdoors based on the collected data, and correcting the heading based on the determination of whether the device is indoors or outdoors.

Particle filter based heading correction

A method for determining an environmental pressure change affecting a pressure sensor within a portable device to determine an elevation of the portable device is disclosed. The method involves estimating a location of the mobile device, estimating an atmospheric pressure associated with the mobile device at a server based on data indicative of atmospheric pressure received from the mobile device, and generating the elevation of the mobile device based on the atmospheric pressure associated with the mobile device and reference data indicative of an absolute elevation reference. The absolute elevation determined may be based on the estimated location of the mobile device and elevation data obtained from a reference map.

Reducing elevation error with environmental pressure anomaly compensation

Heading constraints in a particle filter

A method for determining an environmental pressure change affecting a pressure sensor within a portable device to determine an elevation of the portable device is disclosed. The method involves sampling pressure data from at least one stationary pressure sensor in an area surrounding a location of the device, wherein the stationary pressure sensor in not within the portable device. The sampled pressure data is then interpolated to a time interval and a difference is computed between the interpolated pressure data over each time interval to determine a differential pressure. The location of the stationary pressure sensor is determined and the differential pressure is added to a pressure map affecting data near the location. The environmental pressure change is then computed over any interval at the location and subtracted from a pressure measurement of the pressure sensor before computing an elevation of the portable device.

Growing community of inventors

Hanover, MD, United States of America

John Riley Miller