A high resolution inverse synthetic aperture radar (ISAR) technique is presented using modified Doppler history based motion compensation. To this purpose, a novel wideband ISAR system is developed that accommodates parametric processing over extended aperture length. The proposed method is derived from an ISAR-to-SAR approach that makes use of high resolution spotlight SAR and sub-aperture rec...

When a line extends beyond the width of an aperture, its direction of motion cannot be detected correctly. Only the component of motion perpendicular to the line is detectable (aperture problem). Early visual areas face the same aperture problem because receptive field sizes are relatively small. The susceptibility of early visual areas to the aperture problem opens an opportunity to measure th...

Synthetic Aperture (SA) imaging, including holographic aperture ladar (HAL), synthetic aperture ladar (SAL), and combinations thereof; are promising solutions for long range imaging applications. One of the major difficulties with real-world SA imaging is coherently processing the image information in the presence of atmospheric turbulence. Differential SAL imaging was proposed and patented in ...

Recent coded aperture imaging systems have shown great success in scene reconstruction, extended depth-of-field and light field imaging. By far nearly all solutions are built on top of commodity cameras equipped with a single spherical lens. In this paper, we explore coded aperture solutions on a special non-centric lens called the crossedslit (XSlit) lens. An XSlit lens uses a relay of two ort...

Cassava varieties, TME419, TMS30572, and TMS98/0505, were planted and harvested at 3-month intervals of 10, 13, and 16 months, respectively. A central composite response surface design was used to study the effects of the variables cassava variety, harvesting time, and shredding aperture on selected physicochemical properties of Ighu samples. Regression models showed that the experimental varia...

This paper describes a way to synthesize a larger coherent aperture from smaller apertures combined with motion, when only intensities are measured. It relies on collecting intensity patterns in two planes for each aperture, for example, the aperture plane and an image plane, and using a phase-retrieval algorithm to reconstruct the optical field in the aperture plane. As the sensor moves forwar...

The finite depth of field of a real camera can be used to estimate the depth structure of a scene. While the distance of an object from the plane in focus determines the defocus blur size, the shape of the aperture determines the shape of the blur. This blur shape can be manipulated by introducing masks into the main lens aperture. We propose an intuitive criterion to design aperture patterns f...

OBJECTIVE To define baseline aesthetic dimensions of the nasal aperture in 3 different racial groups. METHODS Healthy volunteers from 3 different racial groups (15 white, 15 Chinese, and 15 Indian men) were enrolled in the study at the Department of Otolaryngology, University of Dundee, Dundee, Scotland. Those with a history of nasal or facial surgery or trauma were excluded from the study. I...

—In this paper, we propose a lensless compressive sensing imaging architecture. The architecture consists of two components, an aperture assembly and a sensor. No lens is used. The aperture assembly consists of a two dimensional array of aperture elements. The transmittance of each aperture element is independently controllable. The sensor is a single detection element, such as a single photo-c...

As opposed to visual imaging, biosonar imaging of spatial object properties represents a challenge for the auditory system because its sensory epithelium is not arranged along space axes. For echolocating bats, object width is encoded by the amplitude of its echo (echo intensity) but also by the naturally covarying spread of angles of incidence from which the echoes impinge on the bat's ears (s...