Abstract: The satellite selection method as utilized by the spaceborne Global Positioning System receiver provides navigational solutions and is designed for use in low Earth orbit. The satellite selection method is a robust algorithm that can be used a GPS receiver to select appropriate GPS satellites for use in calculating point solutions or attitude solutions. The method is takes into account the difficulty of finding a particular GPS satellite phase code, especially when the search range in greatly increased due to Doppler shifts introduced into the carrier frequency. The method starts with an update of the antenna pointing and spacecraft vectors to determine the antenna backplane direction. Next, the GPS satellites that will potentially be in view of the antenna are ranked on a list, whereby the list is generated based on the estimated attitude and position of each GPS satellite. Satellites blocked by the Earth are not entered on this list.

Abstract: The spaceborne Global Positioning System receiver provides navigational solutions and is designed for use in low Earth orbit. The spaceborne GPS receiver can determine the orbital position of a spacecraft using any of the satellites within the GPS constellation. It is a multiple processor system incorporating redundancy by using a microcontroller to handle the closure of tracking loops for acquired GPS satellites, while a separate microprocessor computes the spacecraft navigational solution and handles other tasks within the receiver. The spaceborne GPS receiver can use either microcontroller or the microprocessor to close the satellite tracking loops. The use of microcontroller provides better tracking performance of acquired GPS satellites. The spaceborne GPS receiver utilizes up to seven separate GPS boards, with each board including its own set of correlators, down-converters and front-end components. The spaceborne GPS receiver also includes telemetry and time-marking circuitry.

Abstract: A trainer for teaching the operation of aircraft fuel systems comprised of a fuselage frame portion and fuel tanks mounted to a platform. The trainer utilizes a fuel look-alike with a viscosity below 2.8 cs and a flashpoint above 200.degree. F.

Abstract: A single screw mechanism with a reduced differential pressure applied to gaterotor teeth. This is accomplished by providing multiple tooth engagement of gaterotor teeth in a particular mainrotor compression chamber. Multiple tooth engagement makes possible the use of metallic gaterotor teeth and the elimination of gaterotor supports used to prevent the disengagement of gaterotor teeth due to high differential pressure.

Abstract: An improved seal design for a Surface Effect Ship, having an inflatable ir seal member, and outer seal member composed of a pliable sheet material scrollably affixed to the hull fore and aft of the inner seal member. The seal may be retracted for hullborne operation by deflating the inner seal member and scrolling the outer seal member tight to hull. The inner seal member has transverse webbing for stability. The outer seal member is periodically scrolled foreward to expose an unworn section to the water surface thereby reducing seal failure due to wear.

Abstract: The invention relates to an impregnation and processing technique for dry fiber composite preform net shapes and ensures maximum mechanical properties in finished structural fiber reinforced composite parts especially in water, and results in composite parts with a low internal void content. The proposed process is not dependent on any pumping action whether due to vacuum or positive pressure to cause the resin to flow into and around the skeletal structure of the dry fiber preform. The process is essentially dependent on the concept of gravity flow in a sandwiched apparatus wherein neat resin cast sheets are placed on both faces of a dry fiber preform shape to create a prepregged (i.e., infiltrated) structure.

Abstract: A mechanism and method for folding the wing of a tilt-rotor aircraft, hav a rotatable load bearing member cooperatively disposed between a high point of the fuselage and the tilt-rotor wing, and a plurality of locking, load bearing pin joints disposed between the fuselage and the tilt-rotor wing, concentric to the rotatable load bearing member, and wherein the tilt-rotor wing may be stored by rotating the tilt-rotor wing, as a single segment, about the rotatable load bearing member, to a position substantially parallel to the fuselage, and wherein the wing may be locked in the flight configuration and the storage configuration with the same pin joints.

Abstract: An apparatus for attaching a pad eye to an underwater ship includes explosives connected to the wings of the pad eye to explosively weld it to the hull of the ship. A water-tight housing holds the pad eye and allows gas to be introduced to drive away all water. Magnets hold the housing to the hull before detonation, a window in the top of the housing allows the diver to observe the entrance of the gas.