Abstract: A gun-launched ramjet projectile follows a classical vacuum ballistic trajectory by maintaining a thrust-drag balance. The thrust of the ramjet is varied by an air door which bleeds air from the duct that leads from the supersonic diffuser at the front of the projectile to the combustion chamber. The control system for the air door includes an actuator and a pair of accelerometers, the output of which is integrated to provide an indication of velocity. The first accelerometer operates during the launching of the projectile in the gun to measure the launch velocity. A second, and more sensitive, accelerometer measures in-flight velocity changes due to atmospheric conditions. Both of the measured velocities are compared with prerecorded standards and error signals are derived representing any velocity deviations. These error signals are combined and then used to drive the air doors which varies the thrust of the ramjet so that it follows the classical vacuum ballistic trajectory.

Abstract: A reference grid for a map matching missile guidance system is generated from a vertically polarized radar map and a horizontally polarized radar map, both of which represent radar returns from a preselected ground area. In generating this reference grid, illuminating radar pulses are alternately fed to a horizontal aperture and vertical aperture of a mapping radar. Horizontal radar returns and vertical radar returns are processed in separate channels to form a radar map of the ground area containing the target to which the missile is to be directed. A pixel-by-pixel comparison of the data in each map is performed to create a polarization diverse map which is essentially those returns from man-made objects. This map is then used by the missile guidance system as a reference grid for a final fix by which the missile obtains its final course orientation enroute to the target.

Abstract: A gun-launched ramjet projectile follows a classical vacuum ballistic trajectory by maintaining a thrust-drag balance. The thrust of the ramjet is varied by an air door which bleeds air from the duct that leads from the supersonic diffuser at the front of the projectile to the combustion chamber. The control system for the air door includes an actuator and a pair of accelerometers, the output of which is integrated to provide an indication of velocity. The first accelerometer operates during the launching of the projectile in the gun to measure the launch velocity. A second, and more sensitive, accelerometer measures in-flight velocity changes due to atmospheric conditions. Both of the measured velocities are compared with prerecorded standards and error signals are derived representing any velocity deviations. These error signals are combined and then used to drive the air doors which varies the thrust of the ramjet so that it follows the classical vacuum ballistic trajectory.