(IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 14, No. 3, 2023 685 | Page www.ijacsa.thesai.org Polarimetric SAR Characterization of Mangrove Forest Environment in the United Arab Emirates (UAE) SoumayaFatnassi 1 , Mohamed Yahia 2 , Tarig Ali 3 , Maruf Mortula 4 MACS Laboratory-National Engineering School of Gabes, University of Gabes, Gabes, Tunisia 1, 2 GIS and Mapping Laboratory, American University of Sharjah, Sharjah, UAE 3 Civil Engineering Department, American University of Sharjah, Sharjah, UAE 4 Abstract—This Mangrove forests in the United Arab Emirates (UAE) provide valuable ecosystem services such as coastal erosion protection, water purification and refuge for a wide variety of plants and animals. Therefore, the first step toward understanding the mangrove forests is the monitoring of this important ecological system. This paper proposes an original study to characterize the mangrove forest environment in the UAE by using polarimetric synthetic aperture radar (PolSAR) remote sensing. Free access C-band dual- PolSAR Sentinel 1 data have been exploited. The elements as of the covariance matrix as well as the entropy/alpha decomposition parameters have been studied. Results show that the VH intensity, the coherence between VV and VH polarimetric channels, the entropy and alpha angle provide the most pronounced signatures that discern mangrove forests. Thus, these parameters could be exploited to improve the accuracy of the remote sensing monitoring and mapping techniques of mangrove forests in the UAE. Keywords—Mangrove forests; dual-PolSAR; sentinel 1; United Arab Emirates; entropy/alpha decomposition I. INTRODUCTION Mangrove forests, which appear in the transitional zones between land and sea in most tropical and subtropical coastlines, play a major role in the coastal ecosystem. In the UAE, mangrove forests are mainly located in tidal lagoons with a total extent estimated to be 38km 2 [2]. They are dominated by gray mangroves (i. e. Avicennia Marina) which tolerate water with high salinity and dry weather conditions (see Fig. 1(c) and Fig. 1(d)). To preserve this important ecosystem, a number of approaches have been proposed to monitor and analyze mangrove forests. Studying mangroves using field methods is time consuming, expensive and difficult because of the harsh environment in mangrove ecosystems. Hence, remote sensing has served as a sustainable tool in studies of mangrove forests. A number of methods have been proposed to monitor and analyze mangrove forests using remote sensing data [17], [10], [11]. Regarding the remote sensing data sources, most previous studies can be grouped into two main groups, those employing optical data and those using Synthetic Aperture Radar (SAR) data. Optical remote sensing data have been widely used for mangrove monitoring due to the availability of very high temporal and spatial resolution imagery [17], [10], [11]. Nevertheless, such systems are limited in utility by the cloud at mangrove sites and by narrow spatial coverage. Few studies have been conducted to map the mangrove forests in the UAE using optical remote sensing data [6], [7], [8]. Synthetic aperture radar (SAR) data have been explored for mangrove forest mapping. SAR offers benefits that include no sensitivity to cloud or precipitation, wide spatial coverage and sensitivity to the geometrical structure of forests (Zhang et al., 2018). In the literature, several studies have been proposed to study the mangrove forests including bio-mass estimation [16], mapping [5], discrimination of species [15], etc. However, there is no study exploiting SAR data in UAE mangrove forest monitoring. The objective of this paper is to fill this gap. Full polarimetric SAR (PolSAR) data provide much more backscattering information of mangrove forests than single polarization data [9]. Nevertheless, the majority of currently- available SAR data, such as the free-access Sentinel-1 (VV and VH polarizations) and ALOS (HH and HV polarizations) data, are dual (not full) PolSAR. In comparison to full-pol, dual-pol mode is widely used in the radar remote sensing applications due to its high spatio-temporal coverage. However, little attention has been given in the literature to entropy-alpha-anisotropy polarimetric target decomposition for mangrove forest analyses despite its wide application for the analysis of vegetation polarimetric responses [3]Using L-band ALOS PALSAR full-pol data, it has been demonstrated that Entropy-alpha-anisotropy target decomposition provided valuable measures of scattering mechanisms of the mangrove forest structure [3]. It has been demonstrated that ALOS PALSAR dual-pol entropy-alpha-anisotropy parameters improved the classification accuracies of mangrove species [20]. In this paper, an extended analysis of the dual-pol response of mangrove forest in the UAE is proposed. The dual-pol parameters including the elements of the covariance matrix as well as the entropy/alpha decomposition parameters are studied to derive strong signatures of the mangrove forests. Single look complex VV and VH Sentinel 1 dual-pol data are tested in this study. This paper is organized as follows: Section II introduces the study area and the experimental data. Section III introduces dual SAR polarimetry. In Section IV, the polarimetric response