Patent ID: 11927680
Assignee: POLARIS WIRELESS, INC.
Field: Measurement (Instruments)
Classification: CPC G  H  Y | IPC G  H

Claim 13:
14. A method of estimating measurement bias of barometric pressure measured by a wireless terminal, the method comprising:
receiving, by a data processing system, a Global-Positioning-System-based (GPS-based) estimate of a first elevation made by the wireless terminal;
receiving, by the data processing system, a first measurement of barometric pressure made by the wireless terminal and representative of the first elevation;
receiving, by the data processing system, one or more pressure measurements made by a pressure reference;
generating, by the data processing system, a first reference pressure value that corresponds to the first estimate of the first elevation made by the wireless terminal at a first lateral location, based on (i) the one or more pressure measurements and (ii) the first estimate of the first elevation made by the wireless terminal;
generating, by the data processing system, a first estimate of bias of barometric pressure measured by the wireless terminal based on a difference between (i) the first measurement of barometric pressure made by the wireless terminal and (ii) the first reference pressure value; and
generating, by the data processing system, an enhanced estimate of bias of barometric pressure, by applying a Kalman filter having a current state and a previous state that exists prior to the current state, wherein the current state is based on (i) the first estimate of bias of barometric pressure, (ii) the previous state of the Kalman filter, and (iii) a Kalman gain.