Abstract: Estimating initial heading at start-up of navigation. At least some of the example embodiments are computer-implemented methods including: spawning a plurality of clone processes, each clone process given an identical location and speed, and each clone process given a unique direction; calculating, by each clone process, a respective position at the end of a frame period; terminating clone processes whose position at the end of the frame period is outside a predetermined threshold, the terminating results in remaining clone processes; and determining the heading of the mobile device from the remaining clone processes.

Abstract: Determining a vertical location of a hand-held computing device. At least some of the example embodiments are computer-implemented methods including: generating an estimate of expected vertical location based on items of beacon data received from beacons by a radio receiver of the hand-held computing device, generating an error covariance of the estimate of expected vertical location based on the items of beacon data, calculating a level normalized change based on measurements of barometric pressure by a pressure sensor of the hand-held computing device, calculating the vertical location of the hand-held computing device based on the level normalized change, the error covariance of the estimate of expected vertical location, and the estimate of expected vertical location, and activating a relevant map for a level comprising the vertical location and displaying the vertical location on a display device of the hand-held computing device.

Abstract: Estimating initial heading at start-up of navigation. At least some of the example embodiments are computer-implemented methods including: spawning a plurality of clone processes, each clone process given an identical location and speed, and each clone process given a unique direction; calculating, by each clone process, a respective position at the end of a frame period; terminating clone processes whose position at the end of the frame period is outside a predetermined threshold, the terminating results in remaining clone processes; and determining the heading of the mobile device from the remaining clone processes.