Abstract: A display processor for displaying complex curves includes an initiating processor, responsive to indicia selection signals for producing signals representing at least one coordinate on said indicia, and recursive processor means responsive to said initiating processor for generating a sequence of signals, each signal in the sequence representing different coordinates of said indicia, and for also generating a corresponding sequence of signals representing rate of change of at least one parameter of said coordinates, a comparator responsive to the output of said recursive processor and to instantaneous sweep position for, at times, illuminating the display field when the instantaneous sweep position matches one of the sequence of indicia coordinates.

Abstract: An improved direction finding apparatus for determining the azimuth of a target source of radio frequency signals using in an optimal manner the signals from a central antenna and an associated array of direction finding antennas. The signals of the antennas are repeatedly scanned to generate running averages of the inphase and quadrature phase components of the RF phasors and to thereby reduce the effect of system noise on the measurement of the phasors. A series of computed candidate phasors corresponding to candidate target sources are then compared to the measured phasors and the azimuth of the candidate target having phasors most closely approximating the measured phasors is an optimal determination of the unknown azimuth of the actual target.

Abstract: Equalization apparatus for a communication system transmitting through a time or frequency spread medium. The message to be transmitted is partitioned and transmitted in burst or frame by frame form. Each frame comprises the message (unknown at the receiver) followed by a test signal known at the receiver. Time gaps are provided between the message and test signals to avoid overlapping of the received message and test signals due to time-spreading. The received mutilated signals are processed in the frequency domain to obtain a reconstituted version of the transmitted message in the frequency domain. This is re-transformed into the time domain so that the reconstituted message available at the receiver is a close replica of the message which was originally available only at the transmitter.

Abstract: According to the present invention, a system for audibly recognizing a received signal which is aurally unclassifiable because it is too short or too long in its duration and/or its frequency band is too wide or too narrow, such as occurs in sensor systems, for example, infiltration radars, comprises a signal-storage device such as a magnetic tape recorder/reproducer and motor means for driving the tape at one speed during recording or storage of a received signal and at a different speed, for example a lower speed, during reproducing or retrieval of the signal therefrom. The storage device has means for storing the signal therein as received and means for retrieving the signal from the storage device at a time-rate different from the storing rate, for example a slower rate.

Abstract: This invention relates to a system for audibly recognizing a received signal aurally unclassifiable because of its improper (not clearly bearable) time duration and/or the frequency band occupied thereby. The received signal may be a carrier wave, modulated in amplitude and phase in accordance with the amplitude and phase of a signal to be recognized. In such case, the system includes modulator means for deriving quadrature base-band signal components. The system also includes a signal-storage device, such as a signal recorder movable at one speed during storage of a received signal thereon and at a different speed during retrieval of the signal therefrom, and means for storing the quadrature signal components in the storage device as received.