Whats the difference between the thermopile and the IMU autopilots?
The thermopile autopilot relies on determining a hypothetical horizon (used to adjust / maintain stability) by measuring the temperature difference between the sky and the ground or surface of the Earth (e.g. water) over which the plane is flying. IMU stands for Inertial Measuring Unit and actually has teeny, tiny gyroscopes and accelerometers in the unit that measure the attitude (pitch and yaw) of the plane independent of a horizon. This gives the IMU advantages when traveling through fog and in mountainous regions where a view of the horizon is lost.
