Abstract: System and method for submitting a location of a mobile device to a public service for providing emergency assistance are described. A mobile device can determine that a user is making an emergency call from the mobile device. The mobile device can then enable a location determination function of the mobile device and determine a location of the mobile device. The mobile device can determine the location in multiple attempts, including, in a first time window, attempting to determine a location with low uncertainty and, if the attempt fails, determining a location with high uncertainty in a second time window. The mobile device can then submit the location to a dispatcher through a mobile network operator.

Abstract: Methods, systems and computer program products for radionavigation for swimmers are described. A mobile device configured to estimate a location using radio frequency signals can estimate a position of the swimmer when the mobile device is worn on a limb of the swimmer and periodically submerged. The mobile device can supply auxiliary information to a radionavigation subsystem to correct a navigation solution affected by limb motion of the swimmer and affected by the periodic submersion of the mobile device.

Abstract: Techniques for location source control for paired devices are described. Location source control selects a location source for a mobile device. The mobile device can receive, from an application program, a request for determining a location of the mobile device. The mobile device can determine a first location estimate using a location subsystem of the mobile device. The mobile device can determine whether to provide the first location estimate as input to the application program, or to provide a second location estimate as input to the application program. The second location estimate can be an estimated location of the companion device and determined by the companion device.

Abstract: Techniques for improving positioning performance using categorization of navigation signal environment are described. A mobile device can receive signal environment data. The signal environment data can represent multiple geographic areas. The signal environment data includes a respective signal environment category for each geographic area, each signal environment category corresponding to a degree to which geographic features in the respective geographic area affect reception of the navigation signals. The mobile device can determine that the mobile device is located in a particular geographic area represented in the signal environment data. The mobile device can then select a set of one or more rules for aiding location estimation. The set of one or more rules can correspond to the signal environment category of the geographic area. The mobile device can estimate a location of the mobile device using the navigation signals and under the set of one more rules.

Abstract: Systems, methods, devices and computer-readable storage mediums are disclosed for assisted GNSS velocity estimation. In an implementation, a method comprises: obtaining, by a mobile device, a step-based speed measurement based on sensor data; obtaining, by the mobile device, a step-based speed uncertainty associated with the step-based speed measurement; determining, by the mobile device, that one or more assistance conditions are met; responsive to the determining, assisting a state estimator using the step-based speed measurement and the associated step-based speed uncertainty; and estimating at least one of the position, velocity or speed of the mobile device using the assisted state estimator.

Abstract: Methods, systems and computer program products for determining and filtering potential outliers in RF signals used in radionavigation are described. A radionavigation subsystem of a mobile device can determine a first location estimate of the mobile device. The mobile device can determine a free direction from the first location estimate. The free direction can be a direction along which RF signals may cause greater position errors than RF signals from other directions may cause. The mobile device can determine a potential outlier among the received RF signals, the potential outlier being an RF signal from a signal source in the free direction. The mobile device can indicate to the radionavigation subsystem that a weight of the potential outlier shall be reduced when determining a second location estimate of the mobile device using the RF signals.

Abstract: Crowd-sourced location data from client devices is processed using enhanced filtering techniques in non-realtime by a centralized server process to improve the accuracy and reliability of georeferenced geodata. At a server computer, enhanced filtering techniques make use of future information to improve georeferencing of the geodata. In some implementations, the server computer can be configured to implement batch processing of raw GNSS data and other crowd-sourced location data (e.g., wireless scan data, inertial sensor data) using, for example, a smoothing filter or batch estimator. Augmentation data (e.g., satellite ephemeris data, clock offset and ionospheric delay) and sensor data independent of client devices can also be used by the server computer to augment the crowd-sourced location data to further improve georeferencing of geodata.

Abstract: System and method for submitting a location of a mobile device to a public service for providing emergency assistance are described. A mobile device can determine that a user is making an emergency call from the mobile device. The mobile device can then enable a location determination function of the mobile device and determine a location of the mobile device. The mobile device can determine the location in multiple attempts, including, in a first time window, attempting to determine a location with low uncertainty and, if the attempt fails, determining a location with high uncertainty in a second time window. The mobile device can then submit the location to a dispatcher through a mobile network operator.

Abstract: Systems, methods and computer-readable storage mediums are disclosed for a pedometer with lag correction. In some implementations, a method comprises: determining, by a first pedometer of an electronic device, a first step count based on sensor data provided by a motion sensor of the electronic device; determining, by a second pedometer of the electronic device, a second step count based on a window of the sensor data; responsive to determining that a step was detected by the second pedometer, determining a third step count based on the window of sensor data; and determining a corrected step count based on the third step count.

Abstract: Systems, methods and computer-readable storage mediums are disclosed for a pedometer with lag correction. In some implementations, a method comprises: determining, by a first pedometer of an electronic device, a first step count based on sensor data provided by a motion sensor of the electronic device; determining, by a second pedometer of the electronic device, a second step count based on a window of the sensor data; responsive to determining that a step was detected by the second pedometer, determining a third step count based on the window of sensor data; and determining a corrected step count based on the third step count.

Abstract: Techniques for GNSS positioning using three-dimensional (3D) building models are described. A processor can determine a probable path for a signal from a GNSS space vehicle (e.g., a satellite) to reach the GNSS receiver. The probable path can include one or more specular reflections. The processor can determine a Doppler correction based on the probable path, including inverting a sense of a vector of the Doppler correction for each reflection. The processor can then incorporate the Doppler correction in an estimated velocity of the mobile device, an estimated position of the mobile device, or both.

Abstract: Techniques for GNSS positioning using three-dimensional (3D) building models are described. A processor of a mobile device can determine a lower bound of uncertainty for an estimated position of the mobile device. The processor can receive an estimated position from a GNSS receiver of the mobile device. The processor can acquire geographic feature data including 3D building models of buildings and other geographic features that are located near the estimated position and may reflect GNSS signals. The processor can then determine a lower bound of uncertainty of the estimated position, regardless of an estimated uncertainty provided by a GNSS estimator. The lower bound can be higher (e.g., have a greater error margin) than the uncertainty value provided by the GNSS estimator. The processor can then present the estimated position, in association with an error margin corresponding to the lower bound of uncertainty, on a map user interface of the mobile device.

Abstract: Systems, methods, and computer program products for determining the location and direction of travel of a mobile device using map vector constraints is disclosed.

Abstract: Among other things, we describe a method that includes, on an electronic device, receiving, from a first location system of the electronic device, first data indicative of a first location of the device at a first time, comparing the first data to second data indicative of a second location of the device at a second time, the second data having been received from a second location system of the electronic device, and based on the comparison, determining whether the first data meets a threshold of location data integrity.

Abstract: Methods, program products, and systems of location estimation using a probability density function are disclosed. In general, in one aspect, a server can estimate an effective altitude of a wireless access gateway using harvested data. The server can harvest location data from multiple mobile devices. The harvested data can include a location of each mobile device and an identifier of a wireless access gateway that is located within a communication range of the mobile device. The server can calculate an effective altitude of the wireless access gateway using a probability density function of the harvested data. The probability density function can be a sufficient statistic of the received set of location coordinates for calculating an effective altitude of the wireless access gateway. The server can send the effective altitude of the wireless access gateway to other mobile devices for estimating altitudes of the other mobile devices.

Abstract: System and method for submitting a location of a mobile device to a public service for providing emergency assistance are described. A mobile device can determine that a user is making an emergency call from the mobile device. The mobile device can then enable a location determination function of the mobile device and determine a location of the mobile device. The mobile device can determine the location in multiple attempts, including, in a first time window, attempting to determine a location with low uncertainty and, if the attempt fails, determining a location with high uncertainty in a second time window. The mobile device can then submit the location to a dispatcher through a mobile network operator.

Abstract: Systems, methods and computer-readable mediums are disclosed for rapid reconfiguration of device location systems. In some implementations, a method comprises: determining, by a server computer, a fault in global location data, the server computer configured to periodically communicate with client devices over a network, the global location data being applicable to multiple client devices and independent of any particular location of any particular client device; determining, by the server computer, a potential impact of the faulty global location data on location systems implemented on the client devices; generating, by the server computer, a reconfiguration file including reconfiguration data for reconfiguring the location systems on the client devices to adapt to the faulty global location data; and automatically sending, by the server computer, the reconfiguration file to the client devices.

Abstract: Systems, methods and computer-readable mediums are disclosed for GNSS velocity estimation for pedestrians. In some implementations, a method includes receiving a periodic sensor signal; determining a fundamental motion frequency of the periodic sensor signal; extracting a periodicity feature from the periodic sensor signal based on the fundamental motion frequency; and responsive to the extracting, initiating pedestrian velocity estimation.

Abstract: Systems, methods and non-transitory, computer-readable storage mediums are disclosed for a multimode GNSS odometer. In some implementations, a method comprises: obtaining, by a device, position and velocity data from a sensor embedded in, or coupled to the device; statistically combining, by the device, the position and velocity data to generate a first delta distance travelled by the device over a period of time, the statistical combining including weighting a contribution of an integrated speed to the first delta distance, the integrated speed derived from the obtained velocity data and period of time; filtering, by the device, the first delta distance to generate a filtered first delta distance; and generating, by the device, a first estimate of total distance travelled by the device based on the filtered first delta distance.

Abstract: Methods, program products, and systems of location estimation using a probability density function are disclosed. In general, in one aspect, a server can estimate an effective altitude of a wireless access gateway using harvested data. The server can harvest location data from multiple mobile devices. The harvested data can include a location of each mobile device and an identifier of a wireless access gateway that is located within a communication range of the mobile device. The server can calculate an effective altitude of the wireless access gateway using a probability density function of the harvested data. The probability density function can be a sufficient statistic of the received set of location coordinates for calculating an effective altitude of the wireless access gateway. The server can send the effective altitude of the wireless access gateway to other mobile devices for estimating altitudes of the other mobile devices.