As a subtask inside a main project I need to compute the position (x,y,z) of a quadrotor using an homography.
To do this I will use a camera (attached to the quadrotor) pointing down to an artificial landmark on the floor. Basically I need to compute the extrinsic parameters of the camera to know the pose with respect to the landmark. I know the projective points of the landmark in the camera, and the intrinsic matrix of the camera but I also need the real landmark position [X, Y, Z].
I suppose that Z coordinate is equal to 0 because the landmark is plane, but I am not sure how to compute the real [X,Y] coordinates.
Any idea how to do that?
I am also interested in put the (x,y,z) position of the quadrotor into a control path, anybody knows where I can find info about the most common controllers for do this kind of task?