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Observations of near-Earth asteroids at large phase angles made it possible to obtain a more complete (for ground-based observations) phase dependence of the polarization of the E-type asteroids’ radiation including the maximum of the positive branch of the linear polarization degree. It is shown that the position of the polarization maximum of high-albedo asteroids is noticeably shifted to the decrease...
The paper reports on a new fully-polarimetric instrumentation radar operating at 228 GHz. The radar is designed to operate in FMCW mode and enjoys high angular and range resolutions and fast data acquisition.
In this paper we investigate the double bounce enhancement due to standing water in flooded agricultural fields to assess the capability of an X-band radar to recognize the presence of floodwater under vegetation. The investigation was carried out by analyzing a polarimetric and multifrequency SAR dataset (COSMO-SkyMed, Alos-2, Radarsat-2) collected over the Vercelli district in North Italy, characterized...
We show that indications of spatial dispersion effects on mineral oil slicks are observed by space-borne multipolarization synthetic aperture radar. This is readily perceived by eye when correlating multipolarization synthetic aperture radar observables with the ship track of the dispersion vessel. We investigate real full-polarimetric (linear transmit/linear receive) as well as simulated and real...
We analyzed airborne L-band Synthetic aperture radar data from the Pi-SAR-L2 platform to detect agricultural fields in semi-mountainous areas of Japan. Full-polarimetric data were acquired during the rice growing season after transplanting. We examined the usefulness of single look complex and ortho-rectified data products by attempting polarimetric decompositions for the single look complex data...
The National Aeronautics and Space Administration (NASA) in the United States and the Indian Space Research Organisation (ISRO) are developing a synthetic aperture radar (SAR) mission to map Earth's surface every 12 days, known as the NASA-ISRO SAR (NISAR) Mission. NISAR has completed its preliminary design and successfully passed its Preliminary Design Review in June 2016. This paper describes the...
AfriSAR is an ESA-funded airborne P- and L-band SAR campaign over the African tropical forests of Gabon carried out by ONERA (July 2015) and DLR (February 2016). The different acquisitions were designed in order to collect multibaseline fully polarimetric data allowing the inversion of key forest vertical structure-based parameters, like e.g. forest height and high resolution reflectivity profiles...
SAR polarimetry (PolSAR) can play an important role in change detection both in terms of improving the detection capabilities and providing physical information regarding the change. In agricultural context, such information can be used to help retrieving the phenological stage and eventually identifying stress conditions. In this work, a new change detection based on PolSAR data is proposed. The...
Speckle removal from single-channel and multi-dimensional SAR remains a difficult problem. In this paper, we are investigating the use of a Convolutional Neural Network (CNN), previously applied to the Super-Resolution problem, for speckle removal. Because speckle noise statistics is signal dependent, we are training the neural network on the residual image formed by the ratio of the observed intensity...
NASA's Soil Moisture Active Passive (SMAP) mission has been tuned to perform a Global Navigation Satellite Systems Reflectometry (GNSS-R) experiment. The motivation of this study is to assess the capabilities of GNSS-R for soil moisture determination, biomass monitoring and cryosphere studies. The use for first time of the Polarimetric Ratio (PR) from a spaceborne platform shows significant sensitivity...
The purpose of this paper is to investigate how SAR Tomography (TomoSAR) can be used to estimate ground polarimetric covariances in forest scenarios in order to increase the amount of information that can be extracted from SAR data stacks is beyond the vertical reflectivity profiles. Under the hypothesis of a two-layer model composed by ground and volume contributions, an algorithm is proposed that...
Land cover is an important earth observation parameter for understanding the Earth's ecosystem. Compared with optical sensors, Synthetic Aperture Radar (SAR) enables more rapid land cover monitoring with its all-weather, day-and-night imaging capability. We mosaicked 390 scenes of PALSAR-2 fully polarimetric data acquired in Japan and computed several polarimetric decompositions. Then, we applied...
Synthetic aperture radar data acquired by the Radar Imaging Satellite (RISAT-1) over experimental oil spills is here investigated. One quad-polarization scene in the Fine Resolution Alternate Polarization Stripmap (FRS-2) mode is analyzed to evaluate the potential of using this mode for oil spill observation. Oil slicks of varying type and age are clearly detected in the HH and VV channels, with relatively...
Synthetic aperture radar is used to identify and monitor oil spills. Separation from oil spill look-alikes is an important part of a fully automatic oil spill detection scheme. Here we investigate the polarimetric signatures for oil spills and newly formed sea ice (a well-known look-alike) in fully polarimetric Radarsat-2 satellite scenes. Using the fully polarimetric scenes we calculate four different...
During the Spring of 2014 a Phase-Tilt Weather Radar (PTWR) developed by the University of Massachusetts was deployed within the Dallas-Fort Worth Urban Testbed operated by the CASA Engineering Research Center. During an eight-week period it observed several weather events including severe thunderstorms and stratiform rain. Observations by the phased-array radar were compared to a nearby mechanically-scanned...
Extensive work has been carried out on detecting ships using space-borne Synthetic Aperture Radar (SAR) systems. However, the identification of small vessels is still challenging especially when the sea conditions are rough. In this work, a new detector is proposed based on dual-polarized incoherent SAR images. Small ships have a stronger cross polarization accompanied by a higher cross-over co-polarization...
This paper focuses the attention on the deployment of the SnowSAR sensor by MetaSensing within the NASA's Snow Field Experiment (SNOWEX) campaign, discussing the preliminary results following the mission in Colorado during February 2017. Originally developed as instrument for supporting the Phase A studies for the proposed CoReH2O (Cold Regions Hydrology High-resolution Observatory) Earth Explorer...
We have been engaged in Numerical Solutions of Maxwell equations (NMM3D) for more than fifteen years [1-2]. In this paper, we report on the recent progress of NMM3D on random rough surfaces and discrete random media and their applications in active and passive microwave remote sensing. The random rough surface models were applied to soil surfaces and ocean surfaces. The discrete random media models...
Satellite-based synthetic aperture radar (SAR) has been proven to be an effective tool for maritime safety and security. In this framework, monitoring oil and gas offshore platforms is a key topic taken into account the high risk of accident, e.g. exposed to extreme weather conditions, and the potential threats to the environment, e.g. release of polluting material into the ocean. In this study, offshore...
In this study, we develop a single-baseline Pol-InSAR approach for estimating the ground-to-volume ratios at different polarizations. We then apply it to time series of Pol-InSAR measurements over agricultural crops in C-Band to assess the relationship between these estimated Pol-InSAR parameters and plant biophyical properties such as structure, biomass and water content. The assessment reveals that...
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