公开(公告)号：US20230152490A1

公开(公告)日：2023-05-18

申请号：US18053907

申请日：2022-11-09

Applicant: NextNav, LLC

Inventor： Badrinath NAGARAJAN ,  Prashant DAVE ,  Michael DORMODY ,  Guiyuan HAN ,  Wei LIU

IPC: G01W1/18 ,  G06F7/501

CPC classification number: G01W1/18 ,  G06F7/501

Abstract: A method involves determining an estimated position of a mobile device within a region. Atmospheric data measurement stations are identified within the region. A geographical anomaly is identified within the region that physically intervenes between the mobile device and a first atmospheric data measurement station. Based on a positional relationship between the mobile device, the geographical anomaly, and the first atmospheric data measurement station, it is determined that atmospheric pressure measurements collected at the first atmospheric data measurement station should be conditionally used for determining a reference pressure estimate. The reference pressure estimate is determined using a plurality of atmospheric pressure measurements collected at the atmospheric data measurement stations and conditionally using the atmospheric pressure measurements collected at the first atmospheric data measurement station. An estimated altitude of the mobile device is determined using a measurement of atmospheric pressure at the mobile device and the reference pressure estimate.

公开(公告)号：US20230152489A1

公开(公告)日：2023-05-18

申请号：US18053254

申请日：2022-11-07

Applicant: NextNav, LLC

Inventor： Michael DORMODY ,  Guiyuan HAN ,  Badrinath NAGARAJAN ,  Wei LIU ,  Prashant DAVE ,  Arun RAGHUPATHY

IPC: G01W1/18 ,  G01W1/02

CPC classification number: G01W1/18 ,  G01W1/02

Abstract: Field calibration of a pressure device involves collecting simultaneous pressure data or pressure and temperature data at two devices for multiple time points. Pressure differences between pairs of simultaneous data points of the collected pressure data are calculated. A model is fitted to the pressure differences and the temperatures and/or pressures, and model parameters are used to correct measurements from the second device. Alternatively, a pressure gradient is estimated for a region that encompasses the two devices for each time point. A distance is determined between the two devices. A pressure gradient difference is determined between the two devices for each time point. A pressure difference offset is obtained for one of the pairs of simultaneous data points for each time point. An average pressure difference offset is determined between the two devices and is used to correct measurements from one of the devices.