Abstract: An automatic adaptive sensitivity time control for a ground mapping radar comprises the dynamic range of radar returns for presentation on a video display. A feedback loop including a differential amplifier senses the magnitude of a signal presented to a limit amplifier and compares the same with a clutter threshold reference potential. A low-pass filter in the feedback loop then smooths or averages the clutter deviation from the reference potential to adjust the clutter level out of a log IF amplifier so that the nominal clutter signal level of close-in returns does not exceed a predetermined magnitude. A second embodiment includes a dual time constant filter in the feedback loop. A comparator circuit senses the leading edge of clutter return signals and switches the feedback loop to its faster time constant mode allowing dynamic compression of smaller time constant pulses.

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 sensor employs a laser to obtain a collimated light beam for transmission across the gas effluent of a catalytic cracking process. Particulate matter entrained in the gas flow forward scatters light energy to a collecting aperture which, in turn focuses the scattered light on a first photodetector. A second photodetector receives directly transmitted light energy. A ratio between the output signals of the two photodetectors is derived and presented to a threshold level detector. If the magnitude of the scatter exceeds a predetermined level it is concluded that a catalyst load dump has occurred. The optical system is carefully selected to ensure that only light energy scattered from a sample volume within the entrained gas flow reaches the first photodetector. This is important because it prevents particulate matter on the surfaces of the transparent windows from affecting the operating of the sensor.

Abstract: An AC converter changes the frequency of an incoming voltage waveform to operate an induction motor driving a ventilation system at one or several different speeds. A program followed by a microprocessor utilizes the phase-to-phase incoming voltage waveform in a step-by-step sequence to generate control signals for the switches in a switching matrix. A full-speed subroutine, a three-quarter speed subroutine and a half-speed subroutine are disclosed for the microprocessor.

Abstract: An automatic sampling apparatus for particles suspended in liquid, which maintains particles in suspension by periodically directing and redirecting the liquid first down one branch of a manifold and then down another, and which selectively directs the liquid toward one or more of a plurality of filters, engaging in both operations under the direction of a programmable process controller. Liquid flow rate through the filters is metered, providing information regarding flow rate and volume to the process controller. A minimum of manual handling is required and user exposure to the sampling environment, which may be radioactive, is reduced.