Cotton Crop Biophysical Parameter Study Using Hybrid/Compact Polarimetric Risat-1 Sar Data

Abstract

Abstract-A hybrid-polarity architecture, consisting of transmitting circular polarisation and receiving two orthogonal linear polarisation and also their relative phase, was used to calculate four Stokes parameters. Different parameters like Degree of Polarisation, Alpha angle, Entropy, Anisotropy, Radar vegetation Index and decompositions like Raney decomposition (m-δ), Freeman-2 and 3 component decompositions were derived from these hybrid data. Crop biophysical parameters viz. plant height, plant age and plant biomass of cotton crops grown under two different environments, i.e., rainfed and irrigated in Guajrat, India were studied with respect to derived polarimetric parameters. Right circular transmitted and horizontally (RH) and vertically (RV ) received backscatter values show good relation with the plant height, age and biomass. RH backscatter −13 dB to −7 dB and RV backscatter from −13 to −10 dB were observed for crop biophysical parameters. Volume component of all decomposition showed strong response to the increase in height, age and biomass of the plant. Radar Vegetation index (RVI) values have also shown significant increase from 0.6 to 0.7 with increasing age of the crop. The rate of growth was slow in the initial phase, but fast post mid-July for both early and late sown cases. The polarimetric parameters were found significantly correlated to the above plant biophysical parameters.

Pearl Millet Crop Biophysical Parameter Retrieval From Space Borne Polarimetric SAR Data Using Machine Learning

“…SAR data has found extensive application in retrieving plant parameters as stand‐alone (Chauhan et al., 2018; Dave et al., 2017; Wiseman et al., 2014) and also as an integration with the optical data (Gao et al., 2013). Biophysical parameters like Plant Height (Romero‐Puig & Lopez‐Sanchez, 2021; Xie et al., 2021), Crop Phenology (Vicente‐Guijalba et al., 2014; H. Wang et al., 2019), Biomass (Mandal et al., 2019), Leaf Area Index (LAI) (Bériaux et al., 2015; Sivasankar et al., 2020), etc can be effectively retrieved from radar data.…”

“…Distributed targets are well addressed by incoherent techniques like Freeman-Durden-3 component decomposition (Freeman & Durden, 1998), Yamaguchi-4 component decomposition (Yamaguchi et al, 2005) and Van-zyl Decomposition (Van Zyl et al, 2011). SAR data has found extensive application in retrieving plant parameters as stand-alone (Chauhan et al, 2018;Dave et al, 2017;Wiseman et al, 2014) and also as an integration with the optical data (Gao et al, 2013). Biophysical parameters like Plant Height (Romero-Puig & Lopez-Sanchez, 2021;Xie et al, 2021), Crop Phenology (Vicente-Guijalba et al, 2014H.…”

RISAT-1A (EOS-4) Medium and Fine resolution data utilization for field crop and plantation monitoring

“…Synthetic Aperture Radar (SAR) technology is unaffected by prevailing weather conditions and cloud cover and exhibits exceptional sensitivity to both crop structure and dielectric constant, making it the ideal choice for precise and reliable crop monitoring during foggy, hazy and monsoon season. SAR data has proved to be an effective tool for monitoring rice, which is extensively cultivated during the Kharif season across the country (Chakraborty and Panigrahy, 1997, Haldar et al, 2014Haldar et al, , 2019. Millets have gained recognition recently over cereals for their multitude of health bene ts and their capacity to thrive in extreme climates.…”

“…Sentinel-1 was limited by the vertical polarization and Radarsat 2 was very expensive for small level of applications. Sentinel based studies yielded satisfactory results but saturation in performance occurred particularly for biophysical parameter (Haldar et al, 2019, Srikant et al 2021. The launch of EOS-4 (RISAT-1A) on 14 th February, 2022 serves as workhorse and will be strengthened with further launch of constellation of 1B and series.…”