초록 ▼

An apparatus is disclosed by which radar targets can be imaged in two dimensions for identification at full radar range using relatively moderate speed data processing. Images of targets are found in range and cross-range dimensions from the time history of the targets\wideband spectral response obt

An apparatus is disclosed by which radar targets can be imaged in two dimensions for identification at full radar range using relatively moderate speed data processing. Images of targets are found in range and cross-range dimensions from the time history of the targets\wideband spectral response obtained by a frequency stepping radar. A frequency synthesizer generates a series of N identical signal bursts, each burst comprising n pulses and each of said n pulses being a different frequency. The radar echos from this series of bursts is separated into n-phase and quadrature phase components. These components are processed to calculate and store the relative amplitude of each echo signal and to determine the phase of each echo signal relative to the phase of the corresponding transmitted pulse. Further, the echo signals are inverse Fourier Transformed to generate an n×N Fourier Transform array representing a synthetic target range profile. The series of N range profile signatures is Fourier Transformed, range cell by range cell, to obtain the Doppler spectrum for each range cell. The resulting Doppler frequencies in each range cell are proportional to the target\s angular rate of aspect change relative to the radar and the scatterer cross-range location in the range cell relative to an arbitrary aspect rotation act.

대표청구항 ▼

A device for enabling radar target imaging comprising: a pulse generator for generating a series of pulses; first means connected to said pulse generator for generating a series of N identical signal bursts, each burst comprising n pulses and each of said n pulses being a different frequency; second

A device for enabling radar target imaging comprising: a pulse generator for generating a series of pulses; first means connected to said pulse generator for generating a series of N identical signal bursts, each burst comprising n pulses and each of said n pulses being a different frequency; second means connected to said first means for transmitting at least a portion of said series of N identical signal bursts as a radar signal and for receiving a series of radar echos from said radar signal; third means connected to said second means for separating said series of radar echos into n in-phase and n quadrature phase components for each of said N bursts; means connected to said third means for sampling and holding said n in-phase and n quadrature phase components for each of said N bursts; fourth means connected to said sampling and holding means for converting said n in-phase and n quadrature phase components for each of said N bursts to a digital format; fifth means connected to said fourth means for calculating and storing the relative amplitude of each of said echos, for calculating and storing the phase of each of said radar echos relative to the phase of the corresponding one of said n transmitted pulses for each of said N bursts, for calculating and storing the n element inverse Fourier Transform of each set of n echo signals resulting from each of said N bursts to thereby generate an n×N inverse Fourier Transform array having n range cells for each of said N bursts, and for calculating and storing the N element Fourier transform of each of said n range cells.