Abstract: A satellite tracking antenna system for use on board ship as part of a maritime communications satellite terminal is disclosed. The system has a directional antenna which is continually trained in the direction of the satellite so as to receive signals therefrom and transmit thereto in spite of the continual rolling, pitching and turning movement of the ship as it travels along its course, even in heavy seas. The system includes a platform which is adapted to be mounted at the head of the mast of the ship. A servo control unit receives position and angular rate signals from roll and pitch sensors mounted on the platform, and serves to drive stepper motors through drive units therefor which counteract pitch and roll without the need for gyroscopic stabilization means and without requiring tachometers or other feedback control in the drive units so that the platform always remains level regardless of the pitching and rolling of the ship.

Abstract: A portable knockdown animal pen structure includes three like dimensioned fence or barrier sections that are interlockably connectible to each other to form a free standing three sided enclosure arrangeable intermediate a corral or barn where cattle are contained and a holding chute where the cattle are directed for such matters as vaccinations, blood and pregnancy tests, branding and the like. At least two sections are provided with a gate of which one is used relative to the gate in the corral or barn and the other is movable and releasably lockable to the third section to form two pens or enclosures. In one pen having access to the corral or barn, an animal therefrom is temporarily contained and is denied access to the other pen which has access to the chute and in which an operator is protected from such animal while administering to another animal in the chute.