A small-slope approximation (SSA) is used for numerical calculations of a radar backscattering cross section of the ocean surface for both Kuand C-bands for various wind speeds and incident angles. Both the lowest order of the SSA and the one that includes the next-order correction to it are considered. The calculations were made by assuming the surface-height spectrum of Elfouhaily et al for f...

A theoretical model that describes the power of a scattered Global Positioning System (GPS) signal as a function of geometrical and environmental parameters has been developed. This model is based on a bistatic radar equation derived using the geometric optics limit of the Kirchhoff approximation. The waveform (i.e., the time-delayed power obtained in the delay-mapping technique) depends on a w...

Certain approaches to phase approximation ask as a first step in implementation for a piecewise linear fitting of gain. When the breakpoints are given, there are few ways to determine the slopes of the broken line approximation. In this paper we determine the breakpoints using a divide-and-conquer approach. Results to piecewise linear approximation of gain and of the resulting phase approximati...

A weak instability mode, associated with phase-locked counterpropagating coastal Kelvin waves in horizontal anticyclonic shear, is found in the semigeostrophic (SG) equations for stratified flow in a channel. This SG instability mode approximates a similar mode found in the Euler equations in the limit in which particle-trajectory slopes are much smaller than f /N, where f is the Coriolis frequ...

Global Navigation Satellite System Reflectometry (GNSS-R) is an emerging earth observation method for remote sensing of feature parameters using reflected signals from navigation satellites, and a purely specular bistatic forward scattering means with special right-handed circular polarization incident wave. In this paper, the small-slope approximation model non-Gaussian sea surface used as bas...

Conventional two-step ADC for CMOS image sensor requires full resolution noise performance in the first stage single slope ADC, leading to high power consumption and large chip area. This paper presents an 11-bit two-step single slope/successive approximation register (SAR) ADC scheme for CMOS image sensor applications. The first stage single slope ADC generates a 3-bit data and 1 redundant bit...

Ajtai [Ajt] recently proved that if for some fixed d, every formula in a Frege proof of the propositional pigeonhole principle PHP, has depth at most d, then the proof size is not less than any polynomial in n. By introducing the notion of an “approximate proof” we demonstrate how to eliminate the non-standard model theory, including the non-constructive use of the compactness theorem, from Ajt...

Given a point-cloud dataset sampled from an underlying geometric space X, it is often desirable to build a simplicial complex S approximating the geometric or topological structure of X. For example, recent techniques in automatic feature location depend on the ability to estimate topological invariants of X. These calculations can be prohibitively expensive if the number of cells in the approx...