Abstract: A direction-finding antenna that conforms to flat and semi-flat surfaces is disclosed. It has a low profile in comparison to most existing direction-finding antennas and its surfaces are shaped so that reduced radar reflections and reduced radar cross sections of the antenna assembly are achieved. The antenna assembly has direction-finding characteristics that are essentially equivalent to traditional antennas that have high profiles and that are mounted high and away from external surfaces of platforms for unobstructed views of arriving electromagnetic energy and away from reflected electromagnetic waves and reradiators.

Abstract: A direction-finding antenna constructed from polymer composite materials which are electrically conductive is shown with the polymer composite materials replacing traditional metal materials. An inherent advantage of replacing metal materials is significantly lower radar reflectivity (radar cross section) and lower weight. The reduced radar reflectivity reduces the range of detectability of the antenna by possible adversaries. Despite significantly lower radar reflectivity, the antenna assembly has direction-finding characteristics which are essentially equivalent to traditional metal antennas.

Abstract: A method for measuring the masses of objects in any gravity environment, including microgravity or zero gravity. An object is placed on or attached to a platform that is movable back and forth along a single axis of motion. An actuator is used to oscillate the platform and is controlled to provide a variable spring force. Instantaneous displacement values are obtained and used to calculate the period of oscillation. Values representing the period, the tare mass of the platform, and the spring constant are then used to calculate the mass of the object. The method may use active damping, and may be varied so that the oscillations are angular rather than linear.

Abstract: A device for measuring the masses of objects in any gravity environment, including microgravity or zero gravity. Objects are placed on a platform having a torque restoring means. The platform is rotated from an equilibrium position and released, such that it undergoes angular simple harmonic motion. The device measures the period of oscillation which is used to calculate the mass of the object on the platform.

Abstract: An acoustical line array transducer reflector system for producing conical hell radiation patterns. One side of the ground plane reflector of the system is covered with a chloroprene rubber-cork composition. Three transformers in ferrite cup cores are wired to the line array transducer elements.