Src Corporation

John Charles Dougherty

Robert E Hiemenz

John G Wiley

Gregory A Mesagna

Greg Kliss

Jeffrey John Fontanella

Andrew Nadeau

A method for radar signal processing separates an electric signal generated by Doppler processors of a radar into alternating current (AC) magnitudes with Doppler frequencies corresponding to absolute values between 0.1 and 4 Hz and direct current (DC) magnitudes with no Doppler frequency. An AC line and a DC line are generated, based on the AC magnitudes and the DC magnitudes, respectively, by adding respective energies across Doppler cells for each range cell and subsequently applying CFAR detector algorithm respectively. An energy level difference between an energy spike in the AC line and another energy spike in the DC line is calculated and compared with a threshold set for detecting a breathing target that is stationary. If the energy level difference is greater than the threshold, the breathing target that is stationary is detected and reported to the radar operator.

Method and apparatus for detecting breathing radar targets

A discrete-time, digital filter for notch filtering a complex digital signal, the filter having a transfer function allowing selective filtering of complex signal components. A system for receiving a modulated signal, the system including a processor for adaptively generating filter coefficients of a discrete-time, digital filter, for filtering a complex discrete-time signal, the processor configured to (i.) identify a number of signal samples in a discrete-time signal, and use the signal samples to calculate autocorrelation values sufficient to calculate the filter coefficients, (ii.) solve a system of equations, the system of equations defined by a Toeplitz matrix and a vector to determine the coefficient values, the Toeplitz matrix defined using the autocorrelation values, and the vector defined as the autocorrelation values of a white noise signal.

Discrete time adaptive notch filter

A radar system, comprising: a receive antenna configured to receive a receive signal reflected from a bullet, the receive signal exhibiting a Doppler shift according to the motion of the bullet; and a detector implementing a set of matched filters each configured to determine a measure of correlation between the Doppler shift of the receive signal and one of a set of pre-stored Doppler shifts, wherein each of the pre-stored Doppler shifts respectively represents the Doppler shift of a bullet passing the antenna at a different speed or a distance of a point of closest approach.

System and method for detecting ballistic targets

A system and method for mitigating multipath propagation are disclosed herein. The method may include collecting a plurality of detections of a target, forming a plurality of models each assuming at least one parameter causing multipath propagation, determining which model best fits the detections of the target, using the best fit model to approximate the ground conditions, and using the approximated ground conditions to remove the multipath error from the observed signals.

Methods and systems for mitigating multipath propagation

A method, system and computer program product for calibrating and operating a radar apparatus provides for obtaining calibration response data from, for example, a radar cylinder and a plurality of radar columns, prior to assembling the radar cylinder and plurality of radar columns into an assembled radar apparatus. The calibration response data for the exemplary radar cylinder and the plurality of radar columns is evaluated to provide a simulated response of the assembled radar apparatus. Actual measured responses from the assembled radar apparatus may then be correlated with the simulated response through use of a look-up table. The particular method, system and program product for calibrating and operating the radar apparatus provides for avoidance of field calibration of the assembled radar apparatus, which is generally neither desirable nor feasible under hostile conditions.

Radar apparatus calibration via individual radar components

An RF receiving circuit that selectively attenuates a received RF signal before it reaches sensitive modifying devices, such as a low noise amplifier or an analog to digital converter. The receiving circuit includes a delay element upstream of its attenuator so that high energy pulses of a short duration (for example, less than 10 nanoseconds) can be effectively attenuated despite coupler, detector, threshold and/or switch delays of the attenuation related circuitry.

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Liverpool, NY, United States of America

John Charles Dougherty