When a moving aperture contains a drifting grating, the perception of aperture movement is strongly affected by the grating movement. We have studied this interaction, using a moving circular patch of sinusoidal grating matched to the background in mean luminance. The circular window, or aperture, could be defined either by an abrupt transition from a full-contrast grating to the background (ha...

Aperture Uncertainty One of the key concerns when performing IF sampling is that of aperture jitter or aperture uncertainty. The terms aperture jitter and aperture uncertainty are frequently interchanged in text. In this application, they have the same meaning. Aperture uncertainty is the sample-tosample variation in the encode process. Aperture uncertainty has three residual effects: the first...

In coded aperture imaging the attainable quality of the reconstructed images strongly depends on the choice of the aperture pattern. Optimum mask patterns can be designed from binary arrays with constant sidelobes of their periodic autocorrelation function, the so{called URAs. However, URAs exist for a restricted number of aperture sizes and open fractions only. Using a mismatched lter decoding...

The Nyquist sampling theorem states that band limited signals may be represented without error by sampled data. Among the effects which place additional restrictions on the signal, beyond those which are given by the Nyquist theorem, are aperture effects. Aperture effects such as aperture jitter, and aperture time, contribute to a signal degradation which is frequency dependent. In applications...

In this study, electric field Shielding Effectiveness (SE) of rectangular enclosure with apertures illuminated by vertical polarization plane wave has been studied by using modal method of moment technique. Electric field SE of enclosure with different shape apertures but same area has been c alculated at three different points inside enclosure. To achieve this, assuming appropriate electric fi...