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.

Abstract: Determining building weather profile parameters, and correcting an estimated altitude of a receiver using the building weather profile parameters. Systems and methods for estimating an altitude of a receiver using building weather profile parameters may identify one or more weather profile parameters for a building, determine an initial estimate of a receiver's altitude at a floor inside the building, and use the initial estimate and the identified weather profile parameters to determine a corrected estimate of the receiver's altitude at the floor.

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.

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.

Abstract: Determining building weather profile parameters, and correcting an estimated altitude of a receiver using the building weather profile parameters. Systems and methods for estimating an altitude of a receiver using building weather profile parameters may identify one or more weather profile parameters for a building, determine an initial estimate of a receiver's altitude at a floor inside the building, and use the initial estimate and the identified weather profile parameters to determine a corrected estimate of the receiver's altitude at the floor.

Abstract: Improving an estimated altitude of a receiver by mitigating the effects of transmitter heating. Systems and methods for improving estimates of a receiver's altitude determine a reference pressure at a reference altitude using a temperature measured at a transmitter or another temperature value, an altitude of the transmitter, and a pressure measured by the transmitter or another pressure value. A local reference pressure for a receiver is determined using the reference pressure and other reference pressures from other transmitters. Reference pressures from overheating transmitters may be weighted less than reference pressures from other transmitters when determining the local reference pressure. The local reference pressure is then used to estimate the altitude of the receiver.

Abstract: Using a calibration sensor to calibrate an unstable sensor from a network of unstable sensors. Approaches for using a calibration sensor to calibrate the unstable sensor initially identify an unstable sensor in a geographic region to be calibrated by a calibration sensor using a model of environmental conditions for the geographic region, and then use the model to determine how to calibrate the unstable sensor using the calibration sensor.

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.

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: A light-weight, aluminum core, multi-stabilized, superconducting wire. The superconducting wire has NbTi superconducting filaments embedded in a normal stabilizing copper metal matrix that encapsulates an aluminum central core.

Abstract: A light-weight, aluminum core, multi-stabilized, superconducting wire having improved electrical and mechanical properties. The superconducting wire has NbTi superconducting filaments embedded in a normal stablilizing copper metal matrix that encapsulates an aluminum central core.