I am trying to get this project working. https://sites.google.com/site/tetheredair/ I am wondering if multiple 10 axis IMUs would work with this? There would be at least 7 locations the IMUs would be placed. 1 on each anchor leg about half way up, 1 attached to the balloon (aerostat), 1 attached at the apex point, and one attached at the cargo payload. The IMUs will have to provide feedback to all of the motors so the control PC knows what is happening and can adjust motors accordingly. Should I worry about drift? There will be GPS units next to each IMU to hopefully help but GPS is only accurate to +-1 meter at the very best. Are there chips that will integrate GPS into the Kalman filter?