公开(公告)号：US10655961B2

公开(公告)日：2020-05-19

申请号：US15618314

申请日：2017-06-09

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Arun Raghupathy ,  Andrew Sendonaris

IPC: G01C5/06 ,  H04W4/02

Abstract: Determining an altitude error value associated with an estimated altitude of a mobile device. In certain disclosed systems and methods for determining an altitude error value associated with an estimated altitude of a mobile device, a first error value related to systematic error and a second error value related to statistical error are determined, and the altitude error value is determined using the first error value and the second error value.

公开(公告)号：US10386448B2

公开(公告)日：2019-08-20

申请号：US15238302

申请日：2016-08-16

Applicant: NextNav, LLC

Inventor： Thomas Wolf ,  Michael Dormody

IPC: G01S5/02 ,  G01C5/06 ,  G01S19/45

Abstract: Using atmospheric data from one or more reference nodes to estimate an altitude of a receiver. Assistance data associated with a set of reference nodes within a region is identified, and the assistance data is used to identify atmospheric reference data associated with a subset of selected reference nodes. An estimate of the receiver's altitude is generated using the atmospheric reference data from the subset of reference nodes.

公开(公告)号：US10378894B2

公开(公告)日：2019-08-13

申请号：US15683513

申请日：2017-08-22

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 determined using a measurement of pressure measured by a reference pressure sensor, and determine if a temperature condition is detected. After determining that the temperature condition is not detected, the systems and methods may compute a first estimate of an altitude of a mobile device using the reference pressure. After determining that the temperature condition is detected, the systems and methods may compute an estimate of a pressure at the location of the reference pressure sensor using the reference pressure, a first measurement of temperature that was used to compute the reference pressure, an estimated altitude of the location of the reference pressure sensor, and the reference altitude, and then compute a second estimate of the altitude of the mobile device using the estimate of pressure and a second measurement of temperature that was measured at another location that is different from the location of the reference pressure sensor.

公开(公告)号：US20150127287A1

公开(公告)日：2015-05-07

申请号：US14527041

申请日：2014-10-29

Applicant: NextNav, LLC

Inventor： Thomas Wolf ,  Michael Dormody

IPC: G01L27/00 ,  G01K19/00

CPC classification number: G01L27/005 ,  G01C5/06 ,  G01K19/00 ,  G01L27/002

Abstract: Systems and methods for calibrating individual pressure sensors using mathematical models to compensate for inaccurate measurements of pressure from those pressure sensors are described. Also described are systems and methods for applying those mathematical models to adjust measurements from those pressure sensors during position computations.

Abstract translation: 描述了使用数学模型来校准各个压力传感器的系统和方法，以补偿来自这些压力传感器的压力的不精确测量。 还描述了用于在位置计算期间应用这些数学模型来调整来自这些压力传感器的测量的系统和方法。

公开(公告)号：US12228402B2

公开(公告)日：2025-02-18

申请号：US18539991

申请日：2023-12-14

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Ganesh Pattabiraman ,  Abijith Kumar ,  Thomas Wolf ,  Gary Parsons ,  Christian Gates ,  Deepak Joseph ,  Badrinath Nagarajan

IPC: G01C17/38 ,  G01C5/06 ,  G01C21/10 ,  G01C21/16 ,  G01C25/00 ,  G01S5/00 ,  G01S5/02 ,  G01S19/14 ,  G01S19/40

Abstract: Calibrating an unstable sensor of a mobile device. Systems and methods for calibrating a sensor of a mobile device determine a first estimated position of the mobile device without using any measurement from the sensor of the mobile device, generate a second estimated position of the mobile device using a measurement from the sensor, estimate a sensor error of the sensor using the first estimated position and the second estimated position, and use the sensor error to determine a calibration value for adjusting one or more measurements from the sensor.

公开(公告)号：US12025471B2

公开(公告)日：2024-07-02

申请号：US17931714

申请日：2022-09-13

Applicant: NextNav, LLC

Inventor： Guiyuan Han ,  Badrinath Nagarajan ,  Michael Dormody

IPC: G01C5/06 ,  G01C21/20 ,  H04W64/00

CPC classification number: G01C5/06 ,  G01C21/206 ,  H04W64/003

Abstract: Estimating a difference in height between floors in a building for use in estimating a height or an altitude of one of the floors. A height difference is estimated between a first floor and a second floor based on outdoor temperatures of first and second time periods, an indoor temperature of the first or second time period, and first and second estimated differences in height between the first and second floors that is based on measurements of pressure from mobile devices when the mobile devices were on the first and second floors during the first and second time periods.

公开(公告)号：US11852780B1

公开(公告)日：2023-12-26

申请号：US17654278

申请日：2022-03-10

Applicant: NextNav, LLC

Inventor： Michael Dormody

IPC: G01W1/18 ,  G01C5/06

CPC classification number: G01W1/18 ,  G01C5/06

Abstract: Calibrating weather stations using maximum allowed altitude errors. Particular embodiments described herein include machines that determine a maximum allowed pressure calibration error for a weather station, determine a temperature variation associated with an environment in which the weather station resides, determine a maximum allowed altitude error for the weather station using the maximum allowed pressure calibration error and the temperature variation, and use the maximum allowed altitude error to determine if a first maximum possible altitude error associated with a first approach for estimating an altitude of the weather station exceeds the maximum allowed altitude error. If the first maximum possible altitude error associated with the first approach does not exceed the maximum allowed altitude error, the first approach is used to estimate an altitude of the weather station for use in calibrating a pressure sensor of the weather station.

公开(公告)号：US11841285B2

公开(公告)日：2023-12-12

申请号：US18157406

申请日：2023-01-20

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Guiyuan Han ,  Badrinath Nagarajan ,  Arun Raghupathy

IPC: G01L27/00 ,  G01C5/06

CPC classification number: G01L27/002 ,  G01C5/06

Abstract: Multiple calibration results for calibrating a barometric pressure sensor based on data received from a device containing the sensor are determined and stored in a table. The table is updated based on rules regarding a relationship between each calibration result and a current calibration value. The calibration results are weighted and combined to determine a combined calibration result. The calibration value for calibrating the sensor is selected from the calibration results, the combined calibration results, or the current calibration value based on a selection criteria.

公开(公告)号：US11761765B2

公开(公告)日：2023-09-19

申请号：US17647826

申请日：2022-01-12

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Deepak Joseph ,  Badrinath Nagarajan ,  Guiyuan Han ,  Arun Raghupathy

IPC: G01C17/38 ,  G01C25/00 ,  G01C5/06 ,  G01S5/02 ,  G01C21/16 ,  G01S19/14 ,  G01C21/10 ,  G01S19/40

CPC classification number: G01C17/38 ,  G01C5/06 ,  G01C21/10 ,  G01C21/165 ,  G01C25/00 ,  G01C25/005 ,  G01S5/02 ,  G01S19/14 ,  G01S19/40

Abstract: Calibrating a pressure sensor of a mobile device incudes determining an absolute calibration value used to calibrate pressure measurements by a pressure sensor of a mobile device; determining a first revisit zone as a first location to which the mobile device repeatedly returns; determining first and second calibrations for first and second visits to the first revisit zone; determining a first relative calibration adjustment value based on a difference between the first and second calibrations; determining an adjusted absolute calibration value based on a sum of the absolute calibration value and the first relative calibration adjustment value; and estimating an altitude of the mobile device based on a pressure measurement by the pressure sensor and the adjusted absolute calibration value.

公开(公告)号：US11733119B2

公开(公告)日：2023-08-22

申请号：US17443135

申请日：2021-07-21

Applicant: NextNav, LLC

Inventor： Michael Dormody ,  Guiyuan Han ,  Badrinath Nagarajan

IPC: G01L27/00 ,  G01L19/00 ,  G01C21/20

CPC classification number: G01L27/005 ,  G01L19/00 ,  G01C21/206

Abstract: Determining when to calibrate a pressure sensor of a mobile device. Particular systems and methods determine values of a plurality of metrics, determine weights for the metric values, determine weighted metric values by applying the weights to the metric values, use the weighted metric values to determine if a pressure sensor of the mobile device should be calibrated using information associated with the first location, and calibrate the pressure sensor of the mobile device using the information associated with the first location if a determination is made that the pressure sensor of the mobile device should be calibrated using information associated with the first location.