公开(公告)号：US10704905B2

公开(公告)日：2020-07-07

申请号：US15676454

申请日：2017-08-14

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Badrinath Nagarajan ,  Guiyuan Han

IPC: G01C5/06 ,  G01C25/00 ,  G01K7/00 ,  G01L7/00

Abstract: Identifying and estimating values of atmospheric conditions for use in estimating an altitude of a mobile device. Systems and methods for monitoring one or more conditions before estimating an altitude of a mobile device may receive a reference pressure that was computed using a measurement of pressure from a first reference pressure sensor at a first location, wherein the received reference pressure specifies an estimated pressure for a reference altitude, and determine if a threshold change in measured pressure by the first reference pressure sensor is detected. If the threshold change in measured pressure is detected, the systems and methods may compute a calibration value for the first reference pressure sensor, or if the threshold change in measured pressure is not detected, the systems and methods may identify a previously-determined calibration value. The systems and methods may then compute an adjusted reference pressure using the received reference pressure and either the computed calibration value or the previously-determined calibration value, and compute an estimate of the altitude of the mobile device using the adjusted reference pressure and a measurement of pressure from the mobile device.

公开(公告)号：US10477358B1

公开(公告)日：2019-11-12

申请号：US16364676

申请日：2019-03-26

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Guiyuan Han ,  Badrinath Nagarajan

IPC: H04W24/00 ,  H04W4/029 ,  G01L19/00 ,  G01L27/00 ,  H04W4/33 ,  G01C21/20 ,  H04W4/021

Abstract: Determining whether a mobile device is inside an environment experiencing adverse pressure variation conditions. Particular systems and methods for determining whether a mobile device is inside an environment experiencing adverse pressure variation conditions detect a change in pressure measured by a mobile device that is caused by an HVAC effect of a building or a vehicle, determine a likelihood that the mobile device is inside a building based on an estimated position of the mobile device relative to the building, and determine that the mobile device is inside the building or inside a vehicle based on the likelihood that the mobile device is inside the building.