A method for measuring a height on a plane, implemented by an electronic device, includes displaying an altitude obtained in a first detection manner, and displaying an altitude obtained in a second detection manner when a first switching condition is met. In this way, the electronic device displays an altitude detected based on a barometric pressure sensor. When a barometric pressure value of an environment in which the electronic device is located is inconsistent with an atmospheric pressure value, the data of the barometric pressure sensor is invalid. The electronic device displays an altitude obtained in another detection manner. In this way, the electronic device can display an accurate altitude in a case in which a user takes a plane.

Power can be preserved in a tracking device equipped with a GPS receiver and a transceiver by evaluating the proximity of the tracking device to a mobile device and enabling the GPS receiver and transceiver only in the event that the tracking device is out of the range of the mobile device. Once enabled, the location of the tracking device can be determined based on location information received from the GPS receiver. The determined location can be provided to a tracking system associated with the tracking device. The tracking system can then inform an owner of the tracking device of the determined location. Once the tracking device has been found, the GPS receiver and the transceiver can be disabled to save additional power.

Power can be preserved in a tracking device equipped with a GPS receiver and a transceiver by evaluating the proximity of the tracking device to a mobile device and enabling the GPS receiver and transceiver only in the event that the tracking device is out of the range of the mobile device. Once enabled, the location of the tracking device can be determined based on location information received from the GPS receiver. The determined location can be provided to a tracking system associated with the tracking device. The tracking system can then inform an owner of the tracking device of the determined location. Once the tracking device has been found, the GPS receiver and the transceiver can be disabled to save additional power.

A method of monitoring swimming activity includes: determining at least one of an actual relationship of a mobile device to water or an expected relationship of the mobile device to water; determining ranges to satellites, based on signals received by a satellite positioning system (SPS) receiver of the mobile device, in response to the signals being received by the SPS receiver when the at least one of the actual relationship of the mobile device to water or the expected relationship of the mobile device to water is a desired relationship of the mobile device to water; and determining a location of the mobile device based on the ranges to the satellites.

A method of monitoring swimming activity includes: determining at least one of an actual relationship of a mobile device to water or an expected relationship of the mobile device to water; determining ranges to satellites, based on signals received by a satellite positioning system (SPS) receiver of the mobile device, in response to the signals being received by the SPS receiver when the at least one of the actual relationship of the mobile device to water or the expected relationship of the mobile device to water is a desired relationship of the mobile device to water; and determining a location of the mobile device based on the ranges to the satellites.

An electronic timepiece includes: a power source; a correlation computation unit executing correlation computation processing of sequentially computing a correlation value between a signal sample and a plurality of codes corresponding to a plurality of satellites; a power source voltage determination unit to which a voltage of a power source is inputted and which determines whether the inputted voltage is lower than a first threshold or not, or whether the voltage exceeds a second threshold set to be equal to or higher than the first threshold; and a correlation computation control unit controlling the correlation computation unit to interrupt the correlation computation processing when the power source voltage determination unit determines that the voltage is lower than the first threshold, and to resume the correlation computation processing when the power source voltage determination unit determines that the voltage exceeds the second threshold.

An electronic timepiece includes: a power source; a correlation computation unit executing correlation computation processing of sequentially computing a correlation value between a signal sample and a plurality of codes corresponding to a plurality of satellites; a power source voltage determination unit to which a voltage of a power source is inputted and which determines whether the inputted voltage is lower than a first threshold or not, or whether the voltage exceeds a second threshold set to be equal to or higher than the first threshold; and a correlation computation control unit controlling the correlation computation unit to interrupt the correlation computation processing when the power source voltage determination unit determines that the voltage is lower than the first threshold, and to resume the correlation computation processing when the power source voltage determination unit determines that the voltage exceeds the second threshold.

A mobile device may be configured to build a power mode database for positioning based on the mobile device's location and associate power mode information, including the operating mode that is requested for positioning and the operating mode that is used for positioning at the location. Additional factors may be associated with the location including contextual information, such as user context, environmental context, and temporal context. The power mode database may be a local database on the mobile device or a remote database, such as a crowdsourced database, accessible via a server. The mobile device may access the power mode database based on a current location and requested operating mode, as well as contextual information, to obtain the actual operating mode to be used for positioning at the location.

Systems, methods, devices, computer readable media, and other various embodiments are described for location management processes in wearable electronic devices. Performance of such devices is improved with reduced time to first fix of location operations in conjunction with low-power operations. In one embodiment, low-power circuitry manages high-speed circuitry and location circuitry to provide location assistance data from the high-speed circuitry to the low-power circuitry automatically on initiation of location fix operations as the high-speed circuitry and location circuitry are booted from low-power states. In some embodiments, the high-speed circuitry is returned to a low-power state prior to completion of a location fix and after capture of content associated with initiation of the location fix. In some embodiments, high-speed circuitry is booted after completion of a location fix to update location data associated with content.

A detection method includes: calculating, based on a result of a device having received data from five or more satellites at a first time point, a solution to an equation including first to third variables indicating a three-dimensional position of the device, a fourth variable indicating deviation of internal time of the device, and a fifth variable indicating a time lag caused by a Doppler effect between the device and the satellites; calculating a solution to an equation including the first to fourth variables based on a result of the device received data from four satellites at a second time point different from the first time point and a solution to the fifth variable calculated for the first time point; and outputting positional information of the device based on calculated each solution to the first to third variables for each of the first time point and the second time point.