“…Distributed systems for sensor data fusion with off-the-shelf mobile devices have been used for tracking [ 120 , 121 , 122 , 126 , 147 ], location detection [ 83 , 84 , 123 , 124 , 148 , 149 ], health monitoring [ 99 , 103 , 119 ], user monitoring [ 113 , 150 ], automotive systems [ 151 ] and other purposes.…”