Abstract: Embodiments described herein provide for a system, a non-transitory machine-readable medium, and methods to provide location services. In an embodiment, a method provides receiving at least one indication that an electronic device is in transit to at least one defined location, establishing a first fence boundary for the at least one defined location, receiving an indication that the electronic device has crossed the first fence boundary and is in transit to a defined location, and establishing a second fence for the defined location, where the second fence provides a finer granularity fence for the defined location than the first fence.

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 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: Among other things, we describe a method that includes, on an electronic device, determining that a current quality metric of signals received by a location system of the electronic device does not meet a threshold quality metric, and based on the determination, selecting a recommendation for changing a position of the device in a manner that would alter the current quality metric. This aspect can also include corresponding systems, apparatus, and computer program products stored on a storage device.

Abstract: The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtaining structural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

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: The disclosed embodiments are directed to detecting a user activity based on patterns in location data. In an embodiment, a method comprises: obtaining, by a processor of a computing device, location data; detecting, by the processor, a pattern in the location data; determining, by the processor and based on the detected pattern, an activity associated with a mobile device; and adjusting, by the processor, one or more parameters of a location data filter configured to process the location data.

Abstract: In general, in one aspect, a method includes receiving, on a mobile device, an indication that an application executing on the mobile device has entered a background state, determining, based on data received from a location system of the mobile device, that the mobile device has remained within a geographic area during a time interval, the geographic area being defined by a radius determined according to an application type of the application, and disabling at least a portion of the location system of the mobile device.

Abstract: Among other things, we describe a method that includes, on an electronic device, determining that a current quality metric of signals received by a location system of the electronic device does not meet a threshold quality metric, and based on the determination, selecting a recommendation for changing a position of the device in a manner that would alter the current quality metric. This aspect can also include corresponding systems, apparatus, and computer program products stored on a storage device.

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, 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: The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtaining structural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

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: The disclosed embodiments are directed to detecting a user activity based on patterns in location data. In an embodiment, a method comprises: obtaining, by a processor of a computing device, location data; detecting, by the processor, a pattern in the location data; determining, by the processor and based on the detected pattern, an activity associated with a mobile device; and adjusting, by the processor, one or more parameters of a location data filter configured to process the location data.

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: 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: 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: 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: 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.