Analysis of Circular Polarization Backscattering and Target Decomposition Using Gb-Sar

Abstract

Abstract-Currently, most full-polarimetric synthetic aperture radar (SAR) systems adopt linear polarization (LP). On the other hand, circular polarization (CP) is also becoming popular due to its various benefits over LP. However, since CP-SAR is an emerging technique, there are not many imaging and polarimetric analysis results in the literature. As a fundamental study on CP-SAR, this paper presents the results of an investigation on the CP properties of ground-based SAR (GB-SAR) echoes from various canonical targets and a rice paddy sample. The C-band data acquired in a laboratory environment are analyzed and interpreted by means of several factors such as calibration performance, experimental verification of theoretical scattering matrices, imaging quality and accuracy of scattering decomposition results. The eigenvector-based decomposition of the coherency matrix is adopted, and the performance of CP in retrieving the targets' dominant scattering mechanisms and physical parameters is evaluated from entropy-alpha (H -ᾱ) plane and orientation angle (β) value. Results demonstrate the effectiveness of CP in interpreting and discriminating the SAR image features mainly owing to its distinct advantage of highly reliable received signal strength.

Development of an L-Band SAR Microsatellite Antenna for Earth Observation

“…Recently, a SAR mode that adopts circular polarization signals in transmission while receiving both polarizations has been proposed [9], and its concept referred to CP-SAR (Patent Pending 2014-214905). Application of a ground based full-polarimetric CP-SAR on rice phenology monitoring has been demonstrated [11], showing adequate classification capability of rice paddies. The L-band microsat is designed to support full polarimetric CP-SAR for concept demonstration, but to avoid too large data amounts it should operate mostly in one polarization, that is, transmitting either left-hand-circular polarization (LHCP) or right-hand-circular polarization (RHCP), and receiving both.…”

Utilizing Polarization Diversity in GBSAR Data-Based Object Classification

“…For instance, in [8,9], authors extract polarization properties from various terrain targets, while in [10], singlepolarization and dual-polarization radar data are compared in the hail detection. Recently, investigations of various polarization in GBSAR applications have also shown potential, for example, when dealing with circular polarizations [11,12] or using polarimetric information for target classification [13].…”

Analysis of Ground Based SAR Images Acquired In A Small Urban Area Using Diverse Polarization Configurations

“…So far, excluding a few recent studies (e.g. those described in [4][5][6]), the polarization used in GB radar observations is the linear co-polar vertical (VV) one. A possible reason of this lack is the fact that most of the commercial terrestrial radar systems do not provide the multipolarization capability, and the main use of these terrestrial apparatuses is focused on interferometric processing for deformation measurements, where polarization features so far have been considered of minor concern.…”