“…The development of a new generation of small low-cost underwater vehicles (UVs) has begun to enable oceanographic, environmental assessment, and national security missions that were previously considered impractical or infeasible (Clegg and Peterson, 2003;Clem et al, 2012;Corke et al, 2007;Dunbabin et al, 2005;Packard et al, 2013;Steele et al, 2012;Zhou et al, 2014). These small lowcost robotic vehicles commonly employ micro-electro-mechanical systems (MEMS) IMUs comprised of 3-axis MEMS magnetometers, angular rate sensors, and accelerometers to estimate local magnetic heading, pitch, and roll, typically to within several degrees of accuracy, but require careful soft-iron and hard-iron calibration and compensation to achieve these accuracies (Crassidis et al, 2007;Guo et al, 2008;Hamel and Mahony, 2006;Mahony et al, 2008Mahony et al, , 2012Metni et al, 2005Metni et al, , 2006Wu et al, 2015).…”