US 12,405,110 B2
Systems and methods for pressure-based estimation of a mobile device altitude or calibration of a pressure sensor
Michael Dormody, San Jose, CA (US); Badrinath Nagarajan, Cupertino, CA (US); and Guiyuan Han, San Jose, CA (US)
Assigned to NextNav, LLC, Santa Clara, CA (US)
Filed by NextNav, LLC, Sunnyvale, CA (US)
Filed on Nov. 23, 2022, as Appl. No. 18/058,421.
Application 18/058,421 is a continuation of application No. 16/405,687, filed on May 7, 2019, granted, now 11,536,564.
Claims priority of provisional application 62/745,175, filed on Oct. 12, 2018.
Prior Publication US 2023/0113234 A1, Apr. 13, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G01C 5/06 (2006.01); G01L 27/00 (2006.01)
CPC G01C 5/06 (2013.01) [G01L 27/002 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method comprising:
determining if a reference-level pressure value based on one or more measurements of pressure from a network of weather stations should or should not be used to calibrate a pressure sensor of a mobile device by:
determining a period of time since an initial time when the reference-level pressure value was determined or since the one or more measurements of pressure on which the reference-level pressure value is based were measured; and
determining if the period of time is less than a first threshold amount of time, wherein a first determination is made that the reference-level pressure value should be used when the period of time is less than the first threshold amount of time, and a second determination is made that the reference-level pressure value should not be used when the period of time is not less than the first threshold amount of time;
if the first determination is made that the reference-level pressure value should be used, using the reference-level pressure value to calibrate the pressure sensor of the mobile device; and
if the second determination is made that the reference-level pressure value should not be used:
(a) determining a trend in a plurality of reference-level pressure values, wherein the trend indicates a change in the plurality of reference-level pressure values in time;
(b) at a first time, determining a first estimated reference-level pressure value based on the trend; and
(c) using the first estimated reference-level pressure value to calibrate the pressure sensor of the mobile device.