The direct estimation of sea-state bias (SSB) from sea height residuals is extended with a parametric fitting process and a successive smoothing of the remaining residuals. This hybrid method essentially produces a nonparametric SSB model in the form of a smooth grid in a 2dimensional space determined by significant wave height and backscatter coefficient. The hybrid method allows a much higher...

This paper presents the results of a study carried out to determine the change in wave climate around an array of hypothetical wave devices. The main objective of this work is to investigate the change in wave height in the upstream and downstream of the devices for different levels of wave absorption. This is achieved by modeling the wave devices as porous structures with different porosity le...

This paper evaluates the performance of two numerical wave models, GHOST and STWAVE, with measurements made in an idealized inlet physical model. The emphasis of this paper is on the overall performance of these models in coastal inlets. Both wave models are similar in that they employ a finite-difference method to solve the wave action conservation equation for the steady-state wave spectral t...

In this article an Archimedean spiral antenna is designed and analyzed that has good operation in broadband application. By analyzing this design, the effects that different parameters have on antenna operation will be studied and ways of optimization will be found.  Influences of cavity height and number of turns to obtain good matching and gain in a frequency interval of 4 to 18 GHz will be d...

Wave propagation is used as an advanced tool of determining elastic properties of rocks. In spite of being cheap and non destructive tests of rock mechanics, due to its modernity method is not yet replacing the traditional dear and destructive tests. In order to pave ways of replacing this test and making best use of it all effective factors of such method are to be assessed. One fundamental fa...

Seawalls are sheltering structures used for protecting the coastal regions against wave induced forces. Because of random nature of the wave behavior, application of physical models for the study of wave-structure interaction can be quite efficient. In the present research, physical models of thin flexible walls were constructed and tested in a wave flume subject to generated random waves. The ...

In case of positioning by GPS, the direct signal from the satellite to the receiver is ordinarily utilized, but the multipath signal is regarded as one error source that 81 ION GNSS 18th International Technical Meeting of the Satellite Division, 13-16 September 2005, Long Beach, CA deteriorate the positioning accuracy. In this paper, we focus on characteristics of the reflected signal, and had ...

LIST OF PRINCIPAL SYMBOLS Ey Hz H h k ^-component of electric field strength, z-component of magnetic field strength. Height of aperture. Height of source slot above guiding surface. Phase constant for free space. kx = Decay constant of surface wave. V(h) = Voltage across slot at height h. x,y,z = Rectangular co-ordinates. Phase-change coefficient in ^-direction. Phase-change coefficient of sur...