Abstract

The properties of the returned signals associated with high range resolution (HRR) radars are influenced by Doppler and constantly vary according to the target aspect relative to the radar line of sight. To effectively sort and classify the returned signals the spectral and temporal contents must be measured simultaneously. A 2-D processor implementing the Wigner transform of the received signals is designed and demonstrated. This architecture is based on acoustooptics and provides the time–frequency information related to the scattered chirped signals in real time at the output plane. In this architecture the returned signals modulate the laser beam via a Bragg cell. A cylindrical lens of appropriate focal length is used to dechirp the returned signals and a second Bragg cell to generate the time base, followed by Fourier transform optics. In this paper we discuss the architecture, its performance, and present the results of recent experiments. System performance is discussed in terms of unintentional signal variation, the dechirping lens and Bragg cell aperture and bandwidth.

© 1991 Optical Society of America