Again, it is true that drift exists, but you're mischaracterizing, from [0]: "these errors accumulate roughly proportionally to the time since the initial posi

Again, it is true that drift exists, but you're mischaracterizing, from [0]: "these errors accumulate roughly proportionally to the time since the initial position was input. Therefore the position must be periodically corrected by input from some other type of navigation system." [0]http://en.wikipedia.org/wiki/Inertial_navigation_system#Error http://en.wikipedia.org/wiki/Inertial_navigation_system#Erro...