公开(公告)号：US20220136830A1

公开(公告)日：2022-05-05

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 ,  G01C21/10 ,  G01S19/14 ,  G01C5/06 ,  G01C21/16 ,  G01S5/02 ,  G01C25/00 ,  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：US20220128355A1

公开(公告)日：2022-04-28

申请号：US17646810

申请日：2022-01-03

Applicant: NextNav, LLC

Inventor： Badrinath NAGARAJAN ,  Arun RAGHUPATHY ,  Michael DORMODY ,  Guiyuan HAN

IPC: G01C5/06 ,  G01C25/00 ,  H04W4/33 ,  H04W4/021

Abstract: Methods and machines involve detecting when a mobile device is in a first area and a second area at different times, collecting pressure data from the mobile device and reference sensor(s) to estimate altitudes of the mobile device within the first area and the second area, collecting terrain altitudes associated with the first area and the second area, and using a difference between the estimated altitudes and a difference between the terrain altitudes to determine a height of a floor. The estimated floor height may be used to calibrate a pressure sensor of a mobile device.

公开(公告)号：US20220099444A1

公开(公告)日：2022-03-31

申请号：US17644029

申请日：2021-12-13

Applicant: NextNav, LLC

Inventor： Michael DORMODY ,  Ganesh PATTABIRAMAN ,  Abijith KUMAR ,  Thomas WOLF ,  Gary PARSONS ,  Christian GATES ,  Deepak JOSEPH ,  Badrinath NAGARAJAN

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

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：US20210389204A1

公开(公告)日：2021-12-16

申请号：US17303691

申请日：2021-06-04

Applicant: NextNav, LLC

Inventor： Michael DORMODY ,  Guiyuan HAN ,  Badrinath NAGARAJAN ,  Arun RAGHUPATHY

IPC: G01L27/00 ,  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：US20210356347A1

公开(公告)日：2021-11-18

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

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.

公开(公告)号：US20200072606A1

公开(公告)日：2020-03-05

申请号：US16380120

申请日：2019-04-10

Applicant: NextNav, LLC

Inventor： Badrinath NAGARAJAN ,  Guiyuan HAN ,  Michael DORMODY

IPC: G01C5/06 ,  G01C21/20

Abstract: Extending the spatial coverage of a reference pressure network. Particular embodiments described herein include machines that initially determine that an estimated position of a mobile device resides outside a coverage area of a network of reference pressure sensors. Reference-level pressures corresponding to reference pressure sensors of the network are determined using measurements of pressure from the network of reference pressure sensors. A pressure pattern for a region that includes the estimated position and an area not included in the coverage area of the network is determined using reference-level pressures that were not determined using measurements of pressure from the network of reference pressure sensors. The reference-level pressures corresponding to reference pressure sensors of the network and the pressure pattern are used to determine a reference-level pressure value for use in calibrating a pressure sensor of the mobile device or for use in estimating an altitude of the mobile device.