SYSTEMS AND METHODS FOR DETERMINING A REFERENCE PRESSURE FOR USE IN ESTIMATING AN ALTITUDE OF A MOBILE DEVICE

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. The systems and methods may then compute an adjusted reference pressure using the received reference pressure and either the computed calibration value or the previously-determined calibration value, and compute an estimate of the altitude of the mobile device using the adjusted reference pressure and a measurement of pressure from the mobile device.