1. vector sights - sighting systems using the vector principle and incorporating a mechanical representation of the vectors of the bombing triangle; a. pre-set vector - a sighting system in which the , 2. tachometric or synchronous sights - sighting systems which automatically release the bomb at the correct bombing angle by maintaining the sight line on the target, thus determining the speed relati, 3. angular velocity sight - a sighting system in which the correct release point is determined when the angular velocity of the target relative to the bomb aimer reaches a precomputed value