Northrop Grumman Systems Corporation

Mark D Hischke

Stuart John Collar

Shannon Mary Nelson

David L Richardson

Stephen G Kaiser

Roger Brunner Williams

Beverly Jean Timm

Kenneth Alan Gustafson

Richard Joseph Paul

Dana Lynn Bourbonnais

Gregory Paul Richardson

Infrared communications scheme for use in an embedded system. According to a preferred embodiment, the invention comprises the use of an infrared communications scheme, according to IrDA protocol, which is utilized to transmit and receive data optically between circuit cards housed within an enclosed, embedded system. Preferably, each respective circuit card is provided with an LED and photodiode to respectively transmit and receive data optically. As such, wire connections are eliminated and allows the systems and methods of the present invention to withstand a greater degree of vibration and shock than that of the prior-art systems and methods. Moreover, the systems and methods of the present invention provide increased reliability and provide greater electrical isolation between modules than prior-art systems and methods.

Rugged shock-resistant backplane for embedded systems

Infrared communications scheme for use in an embedded system. According to a preferred embodiment, the invention comprises the use of an infrared communications scheme, according to IrDA protocol, which is utilized to transmit and receive data via an electrical interface between circuit cards housed within an enclosed, embedded system. Preferably, each respective circuit card is provided with a digital tri-stateable transmitter element and a digital receiver to respectively transmit and receive data. The systems and methods of the present invention provide increased reliability than prior-art systems and methods.

Shock-resistant backplane utilizing infrared communication scheme with electrical interface for embedded systems

A method for tuning spread spread spectrum receivers to a frequency of a digital signal within a specified frequency band as the steps of coarse tuning the receiver while a preamble of the digital signal is being received, fine tuning the receiver while the preamble of the digital signal is being received, and demodulating the signal. Preferably, the step of coarse tuning the receiver comprises dividing the specified frequency band into a plurality of first sub-bands, and sequentially measuring a receive signal strength within each of the sub-bands until a receive signal strength is greater than a predetermined threshold. Preferably, the step of fine tuning the receiver comprises the dividing at least one first step-band which is found to have a receive signal strength greater than a predetermined threshold into a plurality of second sub-bands when a receive signal strength is greater than the predetermined threshold, sequentially measuring a receive signal strength within each sub-band so as to determine which second sub-band contains a signal having a receive signal strength above a predetermined threshold, and determining which second sub-band contained the signal with the greatest receive signal strength.

Method for tuning a spread spectrum receiver

An unattended ground sensor for the monitoring of a remote area. The unattended ground sensor comprises a housing that supports a power source, a communications module, at least one sensor module and a mainframe module. Additionally, the unattended ground sensor includes a common electrical bus in electrical communication with the power source, the communications module, the at least one sensor module, and the mainframe module. The common electrical bus is operative to provide a communications pathway between the power source, the communications module, the at least one sensor, and the mainframe module. Accordingly, the mainframe module is operative to control the operation of the unattended ground sensor through the common electrical bus.

Modular open system architecture for unattended ground sensors

A moving target simulator for testing a radar system has a radio frequency receiver, a digital radio frequency memory in electrical communication with the radio frequency receiver for storing a signal received thereby, a digital delay circuit in electrical communication with the digital radio frequency memory for providing a time delay between reception and transmission of the radio frequency signal, an amplitude modulation circuit in electrical communication with the digital radio frequency memory for modulating an amplitude of the radio frequency signal, a Doppler modulation circuit in electrical communication with the digital radio frequency memory for providing a Doppler-modulated signal, and a radio frequency transmitter for transmitting the radio frequency signal after it has been delayed, amplitude-modulated, and/or Doppler-modulated.

Moving target simulator

A method for separating a desired signal from an interfering signal, which is particularly useful when the desired signal is substantially weaker than the interfering signal, includes the steps of providing a combined signal which contains both a desired signal and an interfering signal; performing a Fourier transform upon the combined signal; providing a reference function which is a function of the amplitude, frequency and phase of the interfering signal; performing a Fourier transform upon the referenced function; multiplying the real components of the Fourier transform of the combined signal by the real components of the Fourier transform of the reference signal to form a product; and subtracting the product from the Fourier transform of the combined signal to form transformed data less interference, i.e., the desired signal.

Method for separating a desired signal from an interfering signal

A continuous wave diplex Doppler radar, comprising an oscillator generating a transmit signal having a spectrum at a carrier frequency, the oscillator having a frequency control input, and spread spectrum modulation means coupled to the frequency control input for spreading the spectrum of the transmit signal.

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Algonquin, IL, United States of America

Mark D Hischke