Modal wavefront estimation from its slopes by numerical orthogonal transformation method over general shaped aperture

Refractive error sensing from wavefront slopes.

The problem of measuring the objective refractive error with an aberrometer has shown to be more elusive than expected. Here, the formalism of differential geometry is applied to develop a theoretical framework of refractive error sensing. At each point of the pupil, the local refractive error is given by the wavefront curvature, which is a 2 × 2 symmetric matrix, whose elements are directly re...

A Wavefront Sensing Method for Synthetic Aperture Sonar Autofocus

Synthetic aperture Sonar (SAS) is a technique for improving sonar resolution by using known sonar motion to lengthen the useful sonar aperture. Unfortunately the images formed with a strip-map SAS are rapidly degraded when there is any perturbation from the known flight-path. This paper outlines a new autofocus procedure for improving SAS imagery, based on wavefront sensing techniques from the ...

Iterative Least-Squares Wavefront estimation for general pupil shapes

Multidimensional wavefront estimation from differential delays

The propagating wavefield measured by complex sources-receivers arrangements can be characterized by a delayed waveform in the n-dimensional (n-D) space of measurements. In this paper, we propose a method for the nonparametric estimation of the time of delay function (also referred to as wavefront) that do not require the knowledge of the waveform. The n-D wavefront is estimated by using a leas...

Star-Shaped and L-Shaped Orthogonal Drawings

An orthogonal drawing of a plane graph G is a planar drawing of G, denoted by D(G), such that each vertex of G is drawn as a point on the plane, and each edge of G is drawn as a sequence of horizontal and vertical line segments with no crossings. An orthogonal polygon P is called orthogonally convex if the intersection of any horizontal or vertical line L and P is either a single line segment o...