Reconstruction of the turbulence radial profile from reflectometry phase root mean square measurements

Reconstruction of the turbulence radial profile from the reflectometry phase root mean square measurements

Simple expressions allowing estimation of the turbulent density perturbation from the reflectometry phase root mean square (r.m.s.) measurements and accounting for the turbulence correlation length are given. The numerical procedure for precise turbulence radial profile reconstruction for different turbulence wave number spectra and both O-mode and X-mode reflectometry is proposed. It is valida...

Photometric Measurements of the Radial Halo Profile

Despite the growing scientific awareness of ice-crystal halos, there is surprising lack of quantitative observational data about them. Even the most basic (and often-referenced) angular measurements sometimes consist of casual determinations of the radii of circular-halos with no mention whatever of the intensity distribution. More-complex halos are reported with either freehand drawings or pho...

Sparse Signal Reconstruction from Phase-only Measurements

We demonstrate that the phase of complex linear measurements of signals preserves significant information about the angles between those signals. We provide stable angle embedding guarantees, akin to the restricted isometry property in classical compressive sensing, that characterize how well the angle information is preserved. They also suggest that a number of measurements linear in the spars...

On the square root of quadratic matrices

Here we present a new approach to calculating the square root of a quadratic matrix. Actually, the purpose of this article is to show how the Cayley-Hamilton theorem may be used to determine an explicit formula for all the square roots of $2times 2$ matrices.

First Density Profile Measurements Using FMCW Reflectometry on JET