NextNav, LLC

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.

A pressure change is detected based on pressure measurement data from a barometric pressure sensor of a computing device. A 2D location of the computing device is determined. An altitude change of the computing device is determined using the pressure change. A cumulative altitude offset value is determined by adding the altitude change to a previous cumulative altitude offset value. A terrain-based altitude of the computing device is determined based on the 2D location and terrain data from a geodatabase. An altitude of the computing device is determined based on the terrain-based altitude and the cumulative altitude offset value.

Techniques for open position, navigation, and timing (PNT) access to cellular network supporting accurate and resilient PNT services are described herein. A user equipment (UE) registered to a network configured to provide positioning services may receive the positioning services from the network. Another UE registered to a different network not configured to provide positioning services may also receive the positioning services from the network configured to provide positioning services based on a centralized platform operable to facilitate operations associated with both networks.

Techniques, methods, and solutions for supporting accurate and resilient positioning, navigation, and timing (PNT) services. In some examples, a cellular PNT (Cell-PNT) network may provide end-to-end monitoring and control of PNT capabilities. For example, a server may coordinate resource allocation between devices. The server may receive a service request and requested performance indicators according to a service level agreement. The server may additionally receive determined performance indicators associated with the service. Based on differences between determined performance indicators and requested performance indicators, the server may determine how to adjust resources to satisfy the requested performance indicators. Indication of the adjusted resources may be transmitted to a device associated with the determined performance indicators. The device may adjust data indications and signals based on the adjusted resources.

Device-based barometric pressure sensor calibration involves determining a specific location of the mobile device; determining a general location of the mobile device that encompasses and obfuscates the specific location; transmitting the general location to a server; receiving general calibration data for the general location; determining specific calibration data based on the general calibration data and the specific location; determining a calibration value based on the specific calibration data, the calibration value being for calibrating the barometric pressure sensor.

Pressure-based estimation of a mobile device altitude or calibration of a pressure sensor involves machines that determine 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 or to estimate an altitude of the mobile device. If the reference-level pressure value should be used, the reference-level pressure value is used to calibrate a pressure sensor of a mobile device or to estimate an altitude of the mobile device. If the reference-level pressure value should not be used, a trend in pressure is determined, an estimated reference-level pressure value based on the trend is determined, and the estimated reference-level pressure value is used to calibrate a pressure sensor of a mobile device or to estimate an altitude of the mobile device.

A location context indicates whether a computing device is in an HVAC environment or a non-HVAC environment. When the computing device is in the HVAC environment, an expected altitude of the computing device is obtained, and a measured altitude of the computing device is determined. An altitude difference is determined between the expected altitude and the measured altitude. The HVAC effect is determined based on the altitude difference. A pressure sensor of the computing device is calibrated based on the HVAC effect, or a corrected measured altitude of the computing device is estimated based on the HVAC effect. In some cases, instead of the altitude difference, the HVAC effect is determined based on a pressure difference.

Method includes receiving a first delay time and a first timing measurement by a TMV from a first receiver at a first node. The first timing measurement is generated by comparing a first time associated with a first signal to a first local clock time. The first signal is transmitted by a transmitter at a source. The TMV receives from a second receiver at a second node in a network, a second delay time and a second timing measurement. The second timing measurement is generated by comparing a second time associated with a second signal to a second local clock time. The second signal is transmitted by the transmitter at the source. The TMV generates a correction factor time based on the first timing measurement, the first delay time, the second timing measurement, and the second delay time. The TMV transmits the correction factor time to the second node.

Device-based barometric pressure sensor calibration involves determining a specific location of the mobile device; determining a general location of the mobile device that encompasses and obfuscates the specific location; transmitting the general location to a server; receiving general calibration data for the general location; determining specific calibration data based on the general calibration data and the specific location; determining a calibration value based on the specific calibration data, the calibration value being for calibrating the barometric pressure sensor.

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.