“…With much development over the last few decades, high-performance navigation is relatively mature and today a major challenge is to develop navigation systems with low-cost sensors to achieve acceptable performance (Brown and Lu, 2004). Various alternative sensing technologies, such as radar, laser (Dickman and de Haag, 2009), vision (Ruotsalainen et al, 2010) have been developed for navigation but the geomagnetic field is still considered to be an accurate, reliable and economic source of orientation information. With the development of vector magnetometer technology (Acuña, 2002), solid-state electronic magnetic compasses are making progress as low cost orientation systems.…”