Polarization Ratio Approach to Retrieve the Bare Surface Roughness at X-Band

Abstract

An observation has been carried out at different incidence angle by X-band scatterometer to retrieve the surface roughness when moisture was kept constant. Polarization ratio approach has been proposed to retrieve the surface roughness at constant moisture. A co-polarized (Horizontal-Horizontal; HH and Vertical-Vertical; VV) ratio (p=σ₀HH/ σ₀VV) ratio based model is proposed to retrieve the bare surface roughness. The regression analyses have been carried out to pre-decide the suitable incidence angle to observe the surface roughness (0.5 to 4.18 cm) at X-band. It was found that the suitable incidence angle to observe surface roughness (0.5 to 4.18 cm) at X-band with co-polarization ratio is 35° and least square optimization (LSE) method has been applied to retrieve the surface roughness when moisture is kept constant. The retrieved values of rms heights are in good agreement (root mean square error, RMSE-1.22) with observed values of rms heights. The significance of the results has been tested by F-ratio test and it was found quite significant. This type of results are helpful to use the microwave techniques to assess the surface roughness by the air-borne or space borne sensor and propose the suitable angle of incidence to observe the surface roughness at X-band.

Indexing terms:

• Scatterometer
• Polarimetry
• Surface roughness

Additional information

Notes on contributors

D Singh

D Singh was born in Varanasi, UP, India and he basically belongs to Jaunpur, UP, India. He received his PhD degree in Electronics Engineering from Banaras Hindu University, Varanasi, UP, India. He has more than 14 years experience of teaching and research. He received various fellowships and awards by the national and international bodies. He worked as Visiting Scientist/Post Doc Fellow at Information Engineering Department, Niigata University, Japan; German Aerospace Centre, Germany and Institute for National Research in Informatics and Automobiles, France and visited several other laboratories in other countries. Currently, he is working as Associate Professor in Electronics and Computer Engineering Department, Indian Institute of Technology Roorkee, India. His main research interests involve microwave remote sensing, electromagnetic wave interaction with various media, polarimetrie and interferometric application of microwave data and numerical modeling.

Y. Singh

K P Singh was born in Jaunpur, India. He did his PhD in Electronics Engineering from Banaras Hindu University, Varanasi, UP, India. Currently, he is working as Professor in Department of Electronics Engineering, Institute of Technology, Banaras Hindu University, India. He received several national and international research fellowships and visited various countries for technical and research work. He worked as Visiting Scientist in Canada Space Agency, Canada, Max-Plank Institute, Germany, Nagoya University, Japan and several other institutes and universities. He was director of HBTI, Kanpur, UP, India and Vice-Chancellor of Purvanchal University, Jaunpur, India. His area of research interest is microwave remote sensing, antenna engineering, microwave engineering and plasma engineering.

K P Singh

Y Singh was born in Jaunpur, UP, India. Basically, he is an engineer and did his BTech from HBTI, Kanpur. Currently, he is working as Project Manager (Electrical) in, JP Sidhi Cement Plant, Sidhi, MP, India. His main interest is in mathematical modeling and its interpretations.