The Marconi Company Limited

Paul E Cope

David J Wilson

An optical alignment detector uses a Fresnel bi-prism (12) on the base of which an incoming beam of light is focussed. When the beam is in alignment, it strikes the base substantially normally and is brought to a focus adjacent a ridge (13) of the bi-prism (12). To cope with a second axis of alignment, a second bi-prism (14) having a ridge (15) is placed beneath the first, with the two ridges (13,15) arranged orthogonally so as to produce four possible pupil entrance images which can be received by four photodetectors (17,18,19,20).

Light alignment detection device

An attitude control system for satellites includes a sensor (10) for generating output signals in response to variations in the attitude of the satellite. These signals are applied to a Kalman filter (12) which models the dynamic state of the satellite and instructs an attitude controller (13) to generate control signals for controlling the actuators. The system is responsive to the actual physical performance of the actuators to provide feed back to the modelling circuit.

Satellite attitude control

A rotational motion sensor has a circular, tubular body (1) filled with a fluid. A sensor head (6) forming part of the body houses a movable detecting element in the form of a piston (7) which is magnetically levitated so that it is kept out of contact with the sensor body. Movement of the piston is detected in a number of different ways including using a variable magnetic reluctance pick-off (4, 5).

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Fareham, United Kingdom

Paul E Cope