The Technical University of Denmark (TUD) Synthetic Aperture Radiometer (SARad) is a two-channel demonstration model that can simulate a two-dimensional (2-D) thinned array radiometer having an unfilled aperture populated with several small antenna elements. Aperture synthesis obtained by interferometric measurements using the antenna elements in pairs, followed by an image reconstruction based...

In aperture counters, particles in fluid suspension flow through a small orifice or aperture, causing a change in the electrical resistance of the aperture. This change is sensed by an external electronic circuit and translated into a voltage pulse, the signal height of which is proportional to the volume of the particle in the aperture. These signal pulses are collated into a spectrum of pulse...

The "aperture problem" refers to the inherent ambiguity of the motion generated by an untextured contour moving within an aperture. The limited spatial extent of the receptive fields of neurons in cortical areas like V1 and MT render them susceptible to this problem. Most psychophysical experiments have probed how the visual system overcomes the aperture problem by presenting moving contours be...

Synthetic aperture imaging is a high-resolution imaging technique employed in radar and sonar applications, which construct a large aperture by constantly transmitting pulses while moving along a scene of interest. In order to avoid azimuth image ambiguities, spatial sampling requirements have to be fulfilled along the aperture trajectory. The latter, however, limits the maximum speed and, ther...

In three neuroimaging experiments, face, novel object, and building stimuli were compared under conditions of restricted (aperture) viewing and normal (whole) viewing. Aperture viewing restricted the view to a single face/object feature at a time, with the subjects able to move the aperture continuously though time to reveal different features. An analysis of the proportion of time spent viewin...

An analytical approximate solution of the electromagnetic field on a subwavelength elliptical hole in a thin perfectly conducting screen is presented. Illumination is a linear polarized, normally incident plane wave. A polynomial development method is used and allows one to obtain an easy-to-use analytical solution of the fields, which can be used to build analytical expressions of aperture fie...