A device implementing a system for estimating device location includes at least one processor configured to estimate a first position of a device based on a first set of parameters, the first set of parameters derived from first sensor data obtained on the device, the first set of parameters corresponding to device motion. The at least one processor is configured to estimate a second position of a user of the device based on a second set of parameters, the second set of parameters derived from second sensor data obtained on the device, the second set of parameters corresponding to user motion. Estimating the first and second positions is constrained by a predefined relationship between the device motion and the user motion. The at least one processor is configured to provide at least one of the first position of the device or the second position of the user.