Abstract: Methods and apparatus for a structure function monitor provide for generation of parameters characterizing a refractive medium. In an embodiment, a structure function monitor acquires images of a pupil plane and an image plane and, from these images, retrieves the phase over an aperture, unwraps the retrieved phase, and analyzes the unwrapped retrieved phase. In an embodiment, analysis yields atmospheric parameters measured at spatial scales from zero to the diameter of a telescope used to collect light from a source.

Abstract: A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8° to approximately 6.5°. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

Abstract: A small model of an aircraft is provided in which the operator is seated in the cockpit. The primary flight controls are selectively operable and actuate six variable speed transformers through the movement of control cables operated by the respective flight controls. The amount of current provided by the transformer outputs is directly proportionate to the degree of control movement. The current is used to activate small, variable speed, reversible electric motors which in turn operate rollers set in pairs and aligned on opposite sides in the three primary planes of rotation of a freely movable sphere contained in the forward aircraft housing. In accordance with the forces imparted to the three different controls, movement is transmitted to the sphere. The sphere itself has included within it a plurality of slide projector units each of which will display or project on a single reflective screen a picture of its own particular portion of the sky or ground.