Unmanned aerial vehicles have become more widely used for military, security, building inspection etc. Flight path and collision avoidance are the main research tasks for UAV control. This paper serves as background for a new method, which can be used for UAV onboard trajectory determination. Collecting UAV control methods and their advantages is possible to create one method that collects advantages of various control methods. Trajectory is established by using the image sensor and image processing methods. New method can be used to cancel out inertial navigation system errors like GPS does.