angular rate what would be the sensors you have you don't have direct access to position orientation velocity angular rate you have access to some of those in a noisy way and then others you don't have access at all so GPS gives you a noisy estimate of position sometimes also velocity typically only up to a couple meters accuracy so not super precise but it's a noisy estimate of position typically you put the inertial sensing on your robot so for helicopter maybe you have a three axis gyro so charr is a angular rate sensor so it