<title>Direct Electronic Fourier Transform (DEFT) Spectra For Surveillance And Countersurveillance</title>

Abstract

This paper contains the results of a joint investigation by the US Army Engineer Topographic Laboratories (ETL) and the US Army Tank-Automotive Research and Development Command (TARADCOM). The main emphasis is to describe investigations using Direct Electronic Fourier Transform (DEFT) technology and the DEFT method to generate Fourier transforms for surveillance and countersurveillance. These investigations include quantitative results which are obtained with an early device and a comparison of these results with subjective human judgments. A computer simulation of DEFT spectra is performed for the purpose of bandwith ex-tension and signal-to-noise improvement. DEFT devices are a recent advance in acousto-optic technology. Early devices generate a real-time, one-dimensional Fourier transform of a two-dimensional image. This Fourier transform is a limited bandwidth radio frequency spectrum representing the image. This paper contains a very brief description of DEFT technology and appropriate references on the development of the DEFT device.