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Efficient discrimination of diverse kharif crops, remains crucial for crop monitoring and production forecasting, and plays a pivotal role in decision-making for food security in India. This study aims to harness temporal backscatter data from EOS-04 C-band synthetic aperture data (SAR) payload to achieve precise discrimination among six short-duration (cereal, oilseeds, fibre) and long-duration (fibre, pulses) kharif crops. The study integrates limited ground-truth polygons and a Random Forest machine learning approach for analysing EOS-04 time-series data. The classification accuracies were found to be higher than 75% across all kharif crops, with cereals exhibiting the highest accuracy, succeeded by fibre, oilseed and pulse crops. A key focus lies in identifying optimal polarization combinations for effective discrimination among diverse kharif crop types. The study reveals that the synergistic utilization of dual polarizations outperforms individual co- or cross-polarizations, notably benefiting discrimination of cotton, soybean and groundnut crops. Horizontal–vertical polarizations are found to be most effective for achieving peak accuracies in rice and red gram crops. Furthermore, the analysis indicates a promising potential for early crop assessment, presenting an opportunity to furnish precise crop estimates at least one and a half months before the harvest. [ABSTRACT FROM AUTHOR]

Indian Space Research Organisation (ISRO) has successfully launched its second civilian C-band Synthetic Aperture Radar (SAR) mission onboard Earth Observation Satellite-04 (EOS-04). The SAR data monitors and measures various atmospheric features and parameters. In this paper, we report on the investigation of EOS-04 data for several atmospheric phenomena. One of the crucial parameters for studying atmospheric manifestations in SAR data is ocean surface winds and an algorithm for its retrieval has been developed using EOS-04 data. The wind speed products thus generated are evaluated using observations from the Advanced Scatterometer and subsequently used to study atmospheric phenomena like boundary layer structures. The EOS-04 SAR data is also demonstrated for studying structures associated with tropical cyclones, coupling of rain and wind imprints and distinct signatures of an atmospheric front. The study outcomes are used to interpret atmospheric phenomena and understand backscattering signals from EOS-04 SAR. This indicates the possibility and potential of a gamut of atmospheric phenomena that can be probed using EOS-04 SAR data. [ABSTRACT FROM AUTHOR]

Synthetic aperture radars (SARs) have enabled allweather sensing of land surfaces, which has significantly benefitted surface hydrology. In this article, we explore various hydrological applications enabled by Indian Space Research Organisation’s (ISRO’s) recently launched Earth observation satellite-04 (EOS-04) C-band SAR satellite. We present the preliminary results of EOS-04 driven flood inundation mapping, monitoring of water bodies and study of river dynamics. Novel application of EOS-04 SAR data in estimation of sedimentation rate is presented for Jayakwadi reservoir, Maharashtra, India. Additionally, this article explores the integrated use of SAR and altimeter data for estimation of lake and reservoir water level and volume. We have used multidate observations from EOS-04 SAR and Sentinel-3A/ 3B altimeters to derive river width and estimate area– water level hypsometric curves for reservoirs. Long-term and near real-time availability of EOS-04 data can provide an indispensable tool for monitoring water bodies and extreme events like floods, at regional scales. [ABSTRACT FROM AUTHOR]

Using Mills cross-configuration of multibeam sonar and synthetic aperture technique, a downward-looking synthetic aperture sonar (SAS), used for the sub-bottom profiler is presented here. The real data collected by the downward-looking SAS are processed by the multireceiver SAS range migration algorithm. By analysing the performance of focused target, the buried object in the soft sediment layer below the seafloor can be well-reconstructed. Furthermore, it shows that the presented system has great potential in profiling the sediment layer below the seafloor. [ABSTRACT FROM AUTHOR]

Dual-frequency Synthetic Aperture Radar (SAR) operating in L- and S-band frequencies is one of the primary payloads of the Chandrayaan-2 orbiter. This payload with the capability of imaging in dual frequency (L-band: 24 cm wavelength and S-band: 12 cm wavelength) with full polarimetric mode aims for unambiguous detection, characterization and quantitative estimation of water-ice in permanently shadowed regions over the lunar poles. The payload will address the ambiguities in interpreting high values of circular polarization ratio associated with water-ice observed during previous missions to the Moon through imaging in dual-frequency fully polarimetric SAR mode. Various improved system features such as wide range of resolutions and incidence angles, synchronized Land S-band operations, radiometer mode, are built into the instrument to meet the required science objectives, adhering to stringent mission requirements of low mass, power and data rates. Major scientific objectives of dual-frequency polarimetric SAR payload are: unambiguous detection and quantitative estimation of lunar polar water-ice; estimation of lunar regolith dielectric constant and surface roughness; mapping of lunar geological/morphological features and polar crater floors at high-resolution, and regional- scale mapping of regolith thickness and distribution. [ABSTRACT FROM AUTHOR]

We present InSAR observations of the co-seismic deformation caused by the Mw 7.8 Gorkha, Nepal earthquake. Analysis of Sentinel-1 data revealed about 100 x 100 sq. km surface deformation with ~1 m upliftment near Kathmandu, and ~0.8 m subsidence towards north along the line of sight of the satellite. The maximum deformation is observed about 40 km east--southeast of the epicentre, suggesting eastward propagation of the rupture. Elastic dislocation modelling revealed that the overall rupture occurred on a 170 km long, 60 km wide fault along the strike (286°) and dipping north (dip = 15°) with large amount of slip (4.5 m) confined to the centre (95 x 22 sq. km) and less slip (0.25 m) on the surrounding part of the fault plane. The corresponding moment magnitude is M w 7.75. The area, depth and dip of the modelled fault plane are fairly consistent and overlap with the location of mid-crustal ramp in the Main Himalayan Thrust. We infer that the earthquake was possibly caused by the release of inter-seismic strain energy accumulated in the environs of mid-crustal ramp due to plate boundary forces. [ABSTRACT FROM AUTHOR]

The article informs about Fruit and shoot borer (FSB)-resistant Bt brinjal Event 142 with cry1Fa1 gene has been approved for biosafety research level (BRL)-II field trials by the Genetic Engineering Appraisal Committee (GEAC), the competent authority in India. It mentions about compliance systematic detection of genetically modified (GM) crops would facilitate monitoring for the presence of a GM event in the supply chain.

Mini-SAR is a single frequency (S-band; 13-cm wavelength) Synthetic Aperture Radar (SAR) in a lightweight (~9 kg) package. Previous Earth- and space-based radar observations of the permanently shadowed regions of the lunar poles have measured areas of high circular polarization ratio consistent with volume scattering from water ice buried at shallow (0.1-1 m) depths. This detection is not definitive because of poor viewing geometry and a limited number of observations. Mini-SAR utilizes a unique hybrid polarization architecture, which allows determination of the Stokes parameters of the reflected signal, intended to distinguish volume scattering (caused by the presence of ice) from other scattering mechanisms (e.g. sub-wavelength scale surface roughness). [ABSTRACT FROM AUTHOR]