ELECTROMAGNETIC SCATTERING BY ROUGH SURFACES WITH LARGE HEIGHTS AND SLOPES WITH APPLICATIONS TO MICROWAVE REMOTE SENSING OF ROUGH SURFACE OVER LAYERED MEDIA

• Published in: Electromagnetic waves (Cambridge, Mass.) Mass.), 2009, Vol.95, p.199-218
• Main Authors: Liang, Ding, Xu, Peng, Tsang, Leung, Gui, Zhiqian, Chen, Kun-Shan
• Format: Article
• Language: English
• Subjects: Remote sensing
• ISSN: 1559-8985; 1070-4698; 1559-8985
• DOI: 10.2528/PIER09071413

In this paper, we study the bistatic reflection and transmission properties of random rough surface with large slope and large height. Method of Moment (MOM) is used to solve the surface integral equations for 2D rough surface scattering problem. The modeled rough surfaces are similar to random rectangular grating, so that there are large slopes on the surface. The motivation of the study is to analyze scattering by sastrugi surface in Polar Regions. The ridges on the sastrugi surface have heights of about 20 cm. In microwave remote sensing of land at 5 GHz, 10 GHz, 19 GHz and 37 GHz, these heights are larger than wavelength. Next, we consider the scattering problem of the sastrugi rough surface over multi-layered snow. The bistatic reflection and transmission coefficients from MOM solutions are used as the boundary conditions for multi-layered radiative transfer equations. The radiative transfer equations are solved and the reflectivities are calculated. Numerical results are illustrated as a function of roughness and multi-layered parameters. We demonstrate that rough surface of sastugi, when interactions with layered media, causes increase in reflectivity and the decrease in emissivity. The increase of reflectivity can be attributed to the fact that rough surface with large slope facilitates large angle transmission. The large angle transmission results in increase of subsurface reflection and the possibility of total internal reflection in layered media below the rough surface.