Camera Positioning - Orbits

I have a centre point that want to focus the camera on. My problem is how to use the arrow keys to move the camera in increments in an orbit around the centre point.

I.e. Orb with a camera that can go pole to pole orbit and equator orbit.

Thanks, for the help

Just change the angle and use radiussin(angle) and radiuscos(angle). The third parameter will be the same as for the center.