We established a new algorithm for correlation process in radio astronomy. This scheme consists of the 1st-stage Fourier Transform as a filter and the 2nd-stage Fourier Transform for spectroscopy. The ”FFX” correlator stands for Filter and FX architecture, since the 1st-stage Fourier Transform is performed as a digital filter, and the 2nd-stage Fourier Transform is performed as a conventional F...

An opto-electronic CNN implementation, as it combines the huge inherent computational capabilities of a massively parallel optical system with programmability of the CNN-UM systems, provides an efficient frame for diverse image processing applications. Our optical CNN implementation is based on a new, semi incoherent optical correlator architecture that is superior from several points of view t...

Generally, the GPS-only navigation system cannot provide an accuracy level that is sufficient for use in vehicular applications in all environments. Specifically, in urban canyon environments where the presence of large buildings leads to frequent shadowing of signals, several multipath peaks can potentially exist in the correlator outputs. To this end, it is worth characterizing the multipath ...

This is a continuation of investigation of the spectral dynamic range achievable with the WIDAR correlator. Previous investigations (EVLA Memo 148) were limited by the so-called “splatter” phenomena, which is now understood and avoidable (EVLA Memo 157). This investigation is also stimulated by a desire to evaluate the “correlator chip beat artifact” seen in simulations (NRC-EVLA Memo 32) and t...

We present a semiclassical explanation of the so-called Bohigas-Giannoni-Schmit conjecture which asserts universality of spectral fluctuations in chaotic dynamics. We work with a generating function whose semiclassical limit is determined by quadruplets of sets of periodic orbits. The asymptotic expansions of both the nonoscillatory and the oscillatory part of the universal spectral correlator ...

This paper examines the use of composite filters for improving the effectiveness of a Vanderlugt correlator when used for fingerprint identification. A digital simulation, which accounts for noise sources in the optical setup, is used to design and test composite matched spatial filters. Results are presented for a real time video image database containing 10 seconds of video from 200 fingers. ...

Two different designs of analog correlators for radiometry are compared in this paper. A continuum correlator based on a microwave nonlinear device is a simple and inexpensive way to detect wide-band polarized signals. Analysis and extensive measurements including linearity, dynamic range, amplitude response, phase balance, and stability are presented, and the suitability of the designs for mic...

A fundamental aspect of the WIDAR correlator is that the sampled astronomical datastream from each antenna is accompanied by a model phase stream. This model phase accounts for, amongst other things, natural fringe rate and the fshift frequencies that are used to frequency shift the data stream from each antenna. The phase models of the two antennas of a baseline are used for fringe stopping an...

A new type of electro-optical three-dimensional (3-D) correlator is proposed and demonstrated. A 3-D object scene, observed by multiple cameras from several points of view, is correlated with a 3-D complex computer-generated function. This correlator is a hybridization of the joint transform and the VanderLugt correlators, and, as such, it allows correlations to be made between 3-D real-world o...