Abstract: A method for augmenting a noise-adaptive predictive proportional navigation terminal guidance scheme. In a fourth order configuration with noise adaptive varying gain parameters calculated as a function of time-to-go, this system implements an optimal control law to augment proportional navigation with target and missile information terms and a navigation ratio which is a function of time-to-go. By employing a fourth order system, enhanced use may be made of information already available in the guidance computer and missile control system to decouple target motion information from the missile control signals. Decoupled target motion information facilitates blind-mode operation in the end game, the last few seconds before intercept. Decoupled missile control information enables the airframe to be controlled to predefined orientations for aimed warhead applications.

Abstract: A method of controlling antiaircraft fire is described in which an aircraft is tracked continuously during the flight of a burst of projectiles and the probability of a hit is continuously revised according to the latest target maneuver as the projectiles proceed to the intercept point. If, before all of the projectiles reach the aircraft, the probability of a hit falls below a specified level, another burst of projectiles is fired. As this second burst proceeds to target its computed probability of hit is combined with that of the previously fired burst to determine the cumulative probability of hit of the two bursts taken together. If, before the second burst reaches the target, the cumulative probability falls below the specified level then a third burst is fired. This activity repeats until the cumulative probability of hit is driven up and kept up above the specified level.

Abstract: In a method for automatically measuring aiming errors and correcting aiming values in the aiming and firing of ballistic weapons at moving targets the continuously supplied direction values (A', E'+.sigma.) of a target position measurement, corrected for daily influences and for the superelevation, are compared with the aiming values (.alpha.+.epsilon.) of at least one gun (2) in a series of successive time intervals after storage of the gun aiming values (.alpha.+.epsilon.) in a memory (3) for a period corresponding with the instantaneous time of flight of the projectile (.tau.).

Abstract: Vehicle tracking and position predicting apparatus includes an improved Kalman velocity filter feedback loop having a forward gain matrix for loop coordinate error factors and those of their derivatives; and position predicting computing apparatus in the loop feedback path between the system output and an input error node. Sensor reference target signals (e.g., range, bearing and elevation) are connected as inputs to the filter error node.In accordance with one aspect of the present invention, sensor coordinate reference errors from the input error node are converted to target reference coordinates. Pursuant to a further aspect of the present invention, the gain matrix is varied dependent upon sensor coordinate variables. Gain matrix variations are thus independent of geometry and sensor reference coordinates.

Abstract: A system and method for providing a relative velocity sighting reference in an airborne gunsight system. A head-up display (HUD) frames the target in the pilot's line of sight and a computer-driven cathode ray tube (CRT) display projects an array of sighting indices or dots on the HUD. The computer receives air data and target tracking inputs and controls the CRT display so that the sighting array automatically overlays and follows the target and so that the indices thereof move in a direction and at a velocity to describe the motion of the line of sight of the target required for the target to intercept a bullet fired from the aircraft gun. The pilot maneuvers the aircraft to null the relative motion between the target and the sighting indices, whereby the gun is in position to fire.

Abstract: A system for tracking a moving target from a moving carrier. The tracking system is provided with a device for measuring the position of the target in relation to the carrier and with a servocontrol unit for servo controlling the aiming of the device. The error between the position of the target and a position estimated for it is given by the measuring device in spherical coordinates. The tracking system is further provided with a converting unit, in which the spherical coordinates are converted into cartesian coordinates. A frame of reference changing unit and a trajectory simulator of the target allow the position of the target to be calculated in relation to a cartesian frame of reference of unvarying orientation and fixed in relation to the earth.

Abstract: For scoring of simulated firing of a weapon, having flatwise-angularly sweeping beams of radiation, emitted at the weapon location during a period beginning at or about the instant of simulated firing are used for measuring the position of a target retroreflector in range and in functions of azimuth and elevation. During the same period a calculation is made of the instantaneous positions in range, and in functions of azimuth and elevation, of an imaginary projectile fired from the weapon at the firing instant under conditions then existing, and the relationship is ascertained between the imaginary projectile and each beam in its angular position at interception by the retroreflector. At a scoring instant, when weapon-to-reflector distance equals weapon-to-projectile distance, or when the projectile is at a predetermined elevation relative to the reflector, scoring is based on the relationship of projectile to angular beam position at that instant.

Abstract: The positions of target reflectors at a distance from a measuring station are measured with fan-shaped angularly sweeping beams of radiation emitted from the measuring station and reflected back to a detector there when each beam is intercepted by a reflector. Expected reflector distribution is analyzed to ascertain, as between adjacent reflectors at equal distances from the station, the minimum projected distance expectable between such reflectors in a separation direction in which separation can be maximum and the maximum projected distance between them in the transverse direction. Each of at least two beams has its long cross-section dimension oriented to be at an angle to that of the other and at an angle to the separation direction which is such that its tangent value is greater than the ratio of said maximum distance to said minimum distance.

Abstract: A radar tracking system having a Kalman estimator is disclosed. The estimator is provided with angle and range track error measurements in a coordinate system that is aligned with and normal to the antenna line of sight, commonly referred to as the LOS coordinate system. This estimator implementation uses less computing resources in converting the measurements provided relative to the antenna LOS coordinate system, to predict target position referenced to a stable coordinate system such as geographic, wander azimuth, or inertial.

Abstract: The present invention relates to a target location method, and more particularly to such a system using passive listening devices to determine the range, course and speed of one or more targets simultaneously. The invention may be used effectively against targets which emit either continuous or pulsed electromagnetic energy signals.

Abstract: Fire control apparatus for an antiaircraft weapons system includes manual means for inputting both estimated roll angles and load (g) factors of a maneuvering target aircraft into a fire control computer. In response to other signals received from conventional target tracking and ranging means, the computer first calculates linearly projected future positions of the target aircraft. Corrections, which may be curvilinear, to these projected positions are then calculated from the inputed estimates of aircraft roll angle and load factor. A fire control commander selectively actuates manual controls to cause the fire control computer to combine this correction with the linearly calculated future positions, a substantially more accurate projection of aircraft-gun projectile intercept positions being thereby provided. Control signals corresponding to these new intercept positions are transmitted from the computer to conventional gun laying means to cause the gun to be aimed at the intercept positions.

Abstract: In an airborne armament fire control prediction computer, apparatus for computing smoothed inertial velocity and acceleration components of an observed target in a three-dimensional Cartesian coordinate system. A target tracking sensor mechanization is provided which generates target position, velocity, and acceleration data components in an inertially-stabilized Cartesian coordinate system, whereby improved closed-loop pilot-aircraft weapon control system dynamic stability and accuracy result. Target sensor dynamic tracking accuracy improvement and noise reduction are also obtained by virtue of such inertially stabilized tracking mechanization.