Sperry Corporation

Sperry Rand Corporation

Clarence L Bennett, Jr

Robert D Short, Iii

Richard M Barnes

Carl E Bohman

Robert Price

Harald Wilhelmsen

Hugh C Maguire

George M Vachula

Joseph D DeLorenzo

Harold W Pyle

Robert S Smith

A signal processor for detecting the presence of two signals whose over-all phase or frequency is related by a known rational number. The first signal of frequency .omega.M is raised to the N.sup.th power, while the second signal of frequency .omega.N is raised to the M.sup.th power. The two raised signals are then correlated, energy detected, and compared against a predetermined threshold to provide an indication when both signals are present. By utilizing the known frequency relationship between the two signals the processor yields enhanced detection performance over that achievable by detection of each signal separately.

Signal harmonic processor

An apparatus for control of ground clutter breakthrough in MTI radar which remove hard limited clutter signals while allowing increased detection sensitivity to moving targets when such strong clutter returns are not present. Logic is provided to prevent the removal of strong moving target return even in the presence of hard limited clutter.

Apparatus for control of clutter breakthrough in MTI radar

An incoming signal is tested for the presence or onset of a frequency shift keyed (FSK) signal which alternates at a known rate between two unknown frequencies separated by a known frequency shift. The incoming signal is time delayed an odd multiple of the keying period and the delayed signal is multiplied by the incoming signal to produce sum and difference frequencies when the FSK signal is present. The difference frequency is selected by filtration, demodulated and integrated to produce a useable detector signal. The detector signal is compared with a threshold signal which is generated to discriminate between the FSK signal and other unwanted signals or noise in the communication channel.

Apparatus and method for detecting the onset of a frequency shift keyed

An apparatus and method for detecting the polarization of signals reflected from targets immersed in clutter. Signals reflected from targets illuminated with quasimonochromatic electromagnetic signals such as FMCW radar are received by antennas responsive to orthogonally polarized components of the reflected signals. These received orthogonal signal components are then modified such that one component is phase shifted with respect to the other signal components, and the amplitudes of the signal components are varied according to predetermined angles of polarization. The resulting signals are further analyzed in a processor which detects the polarization of the reflected signals by estimating the Stokes parameters for the reflected signal. The Stokes parameters may then be used to generate detection criteria that are compared to a predetermined threshold level.

Polarization detector

Magnetic-electronic apparatus for sensing the clearance between two ferrous metals, for application in measuring the clearance between a shear bar and the cutting knives of a harvesting farm machine, is disclosed having a magnetic sensor disposed within the shear bar for producing a magnetic field, the interception of which by the passage of a knife produces an electronic signal which is processed by appropriate circuitry for indicating the clearance between the knives and the shear bar.

Magnetic clearance sensor

A guidance assist system is mounted on an agricultural machine for directing the lateral movement thereof with respect to the severed edge of the crop material being harvested thereby. The crop, including the severed edge, is periodically, optically, scanned and an output signal, in response to the reflected illumination therefrom, is generated having a discontinuity therein representative of the severed crop edge. The deviation of this discontinuity from a predetermined point along the scan is determined by the apparatus and an error signal representative thereof is coupled to the utilization means for directing the lateral movement of the agricultural machine such that the error signal is reduced towards zero.

Guidance assist system for agricultural machines

A static magnetic field detector for harvesting machines senses the passage of ferrous or magnetic objects utilizing a balanced magnetic field excitation configuration which provides substantial self-cancellation of spurious background signals. A novel filtering means provides normalization of the fluctuations in the background noise due to the variations in the angular velocity of the rotating harvesting machine components. Additionally, the detector apparatus is disposed within a compressor feed roll of the machine thereby reducing the area which must be scanned and increasing the sensitivity of the device.

Growing community of inventors

Groton, MA, United States of America

Clarence L Bennett, Jr