Abstract: A method that includes monitoring, by a processor of a mobile device, a stream of magnetic field measurements generated by a first sensor as the mobile device is manipulated by a user, with each magnetic field measurement representing an orientation of the mobile device relative to a reference frame. The method also includes a processor that determines a point on the surface of a magnetometer calibration sphere associated with the orientation of the mobile device, and storing the magnetic field measurement to a corresponding data bin, each data bin associated with the corresponding point on the surface of the sphere. The method continues with when the processor determining that the number of data bins containing magnetic field measurements exceeds a specified threshold, the processor triggers a magnetometer calibration process for an attached magnetometer.

Abstract: A method that includes monitoring, by a processor of a mobile device, a stream of magnetic field measurements generated by a first sensor as the mobile device is manipulated by a user, with each magnetic field measurement representing an orientation of the mobile device relative to a reference frame. The method also includes a processor that determines a point on the surface of a magnetometer calibration sphere associated with the orientation of the mobile device, and storing the magnetic field measurement to a corresponding data bin, each data bin associated with the corresponding point on the surface of the sphere. The method continues with when the processor determining that the number of data bins containing magnetic field measurements exceeds a specified threshold, the processor triggers a magnetometer calibration process for an attached magnetometer.

Abstract: A multi-device system for mobile devices to acquire and share 3D maps of an environment. The mobile devices determine features of the environment and construct a local map and coordinate system for the features identified by the mobile device. The mobile devices may create a joint map by joining the local map of another mobile device or by merging the local maps created by the mobile devices. To merge maps, the coordinate system of each system may be constrained in degrees of freedom using information from sensors on the devices to determine the global position and orientation of each device. When the devices operate on a joint map, the device share information about new features to extend the range of features on the map and share information about augmented reality objects manipulated by users of each device.