Fractional order Fourier transform-based fringe-adjusted joint transform correlator
نویسندگان
چکیده
An extended fractional Fourier transform (FRT) based fringe-adjusted joint transform correlator (JTC) for real-time target recognition applications has been implemented. In real-time situation, the input scene is captured using a chargecoupled device camera. The joint input images are fractional Fourier transformed and the joint power spectrum (JPS) has been recorded. Thus obtained JPS is multiplied by a pre-synthesized fringe-adjusted filter (FAF) to yield fractional fringeadjusted JPS (FrFJPS). The FRT based fringe-adjusted JTC (FrFJTC) has been found to yield better results in comparison to the conventional fringe-adjusted JTC (FJTC). Three performance measure parameters; correlation peak intensity, peak-tocorrelation energy and peak-to-sidelobe ratio have been calculated. Computer simulation and experimental results are presented.
منابع مشابه
Adaptive real-time architectures for phase-only correlation.
A video-rate correlator can be constructed with a phase-only spatial light modulator and a CCD camera. The phase of the Fourier transform of a signal and a reference image is determined by fringe-scanning interferometry. The two measured phase images are then subtracted. The optical Fourier transform of this difference produces the phase-only correlation response. This system can update both si...
متن کاملTarget Detection using Adaptive Progressive Thresholding Based Shifted Phase-Encoded Fringe-Adjusted Joint Transform Correlator
A new target detection technique is presented in this paper for the identification of small boats in coastal surveillance. The proposed technique employs an adaptive progressive thresholding (APT) scheme to first process the given input scene to separate any objects present in the scene from the background. The preprocessing step results in an image having only the foreground objects, such as b...
متن کاملNonlinear optical security system based on a joint transform correlator in the Fresnel domain.
A new optical security system for image encryption based on a nonlinear joint transform correlator (JTC) in the Fresnel domain (FrD) is proposed. The proposal of the encryption process is a lensless optical system that produces a real encrypted image and is a simplified version of some previous JTC-based encryption systems. We use a random complex mask as the key in the nonlinear system for the...
متن کاملFractional Fourier Transform Based OFDMA for Doubly Dispersive Channels
The performance of Orthogonal Frequency Division Multiple Access (OFDMA) system degrades significantly in doubly dispersive channels. This is due to the fact that exponential sub-carriers do not match the singular functions of this type of channels. To solve this problem, we develop a system whose sub-carriers are chirp functions. This is equivalent to exploiting Fractional Fourier Transform (F...
متن کاملSpace-variant optical correlator based on the fractional Fourier transform: implementation by the use of a photorefractive Bi(12)GeO(2(a)) (BGO) holographic filter.
A space-variant optical correlator is proposed on the basis of the fractional Fourier transform. The optical device uses as a recording medium for the holographic filter a photorefractive Bi(12)GeO(2) (BGO) crystal. The experimental results confirm the shift-variance properties. Some limitations that arise from the volume diffraction are also considered.
متن کامل