Abstract: An apparatus for an improved antenna tracking system for antennas mounted on an unstable platform. The system comprising a directional antenna, an attitude heading reference system (AHRS) mechanically connected to the at least one directional antenna, a self-scan acquisition and tracking method and an antenna controller connected to the AHRS.

Abstract: A system and method for determining the position of an aircraft. An aircraft signal is received by a first antenna and a second antenna, the first antenna being at a known baseline distance from the second antenna. A processor is used to calculate the time difference of arrival range between the second antenna and the aircraft using a common time reference signal. The position of the aircraft is determined by a position determinator based upon the baseline distance between the first and second antennas, the range between the first antenna and the aircraft, and the time difference of arrival range between the second antenna and the aircraft.

Abstract: An instrument for indirectly measuring the attitude of a moving aircraft includes three accelerometers, a GPS radio receiver, an electronic estimating module, and an electronic output module. The three accelerometers indicate three accelerations of the aircraft respectively along three aircraft body axes. The GPS radio receiver receives from GPS satellites the position and velocity of the aircraft along an earth fixed axis. The electronic estimating module estimates a vector such that a series of aircraft position changes along the three body axes that are caused by the measured accelerations, times the vector, approximately matches a corresponding series of position changes along the earth fixed axis as given by the receiver. The electronic output module generates a visual display of the roll, pitch, or heading of the aircraft by performing trigonometric functions on the vector.

Abstract: A system for determining attitude of airborne vehicles or surface vehicles is provided with three fixed position antennas separated from each other by a predetermined calibrated distance. Each antenna is connected to a GPS receiver and the receiver outputs are coupled to a phase comparator which establishes the phase difference between the RF carrier signal of the three possible pairs of receivers. The outputs of the phase comparator are coupled to a preprogrammed dedicated processor that calculates a coordinate frame which fixes the attitude of the plurality of antennas in space. The processor then makes a comparison with a precalibrated reference attitude stored in an associated memory so that a true attitude value of roll, pitch and yaw may be calculated and employed to reposition the gyro of the moving vehicle.