Browsing by Author "Monti-Guarnieri, Andrea V."

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    Distributed Spaceborne SAR: a review of systems, applications, and the road ahead
    (IEEE, 2025-12-31) Hu, Cheng; Li, Yuanhao; Chen, Zhiyang; Liu, Feifeng; Zhang, Qingjun; Monti-Guarnieri, Andrea V.; Hobbs, Stephen E.; Anghel, Andrei; Datcu, Mihai
    As a crucial sensor for wide-area Earth observation, spaceborne synthetic aperture radar (SAR) plays a pivotal role in large-scale terrain mapping, ocean observation, disaster monitoring, and so forth. Driven by the increasing demands for diverse applications, enhanced performance, and the continuous advancement of satellite and radar technologies, the distributed configuration has emerged as a key developmental trend for spaceborne SAR. This review comprehensively summarizes the systems and typical applications of distributed spaceborne SAR. The system configurations encompass homogenous distributed SAR, formed by multiple identical or similar platforms, and heterogeneous distributed SAR, characterized by significant differences between the transmitting and receiving platforms. Typical applications of distributed SAR include intelligent target recognition, terrain mapping, deformation retrieval, atmosphere measurement, and ocean observation, among others. Finally, the review offers a prospective outlook on the future development of distributed spaceborne SAR.
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    G-CLASS: geosynchronous radar for water cycle science - orbit selection and system design
    (Institution of Engineering and Technology (IET), 2019-11-28) Hobbs, Stephen E.; Monti-Guarnieri, Andrea V. ; Broquetas, Antoni; Calvet, Jean-Christophe; Casagli, Nicola; Chini, Marco; Ferretti, Rossella; Nagler, Thomas; Pierdicca, Nazzareno; Prudhomme, Christel; Wadge, Geoff
    The mission geosynchronous – continental land atmosphere sensing system (G-CLASS) is designed to study the diurnal water cycle, using geosynchronous radar. Although the water cycle is vital to human society, processes on timescales less than a day are very poorly observed from space. G-CLASS, using C-band geosynchronous radar, could transform this. Its science objectives address intense storms and high resolution weather prediction, and significant diurnal processes such as snow melt and soil moisture change, with societal impacts including agriculture, water resource management, flooding, and landslides. Secondary objectives relate to ground motion observations for earthquake, volcano, and subsidence monitoring. The orbit chosen for G-CLASS is designed to avoid the geosynchronous protected region and enables integration times of minutes to an hour to achieve resolutions down to ∼20 m. Geosynchronous orbit (GEO) enables high temporal resolution imaging (up to several images per hour), rapid response, and very flexible imaging modes which can provide much improved coverage at low latitudes. The G-CLASS system design is based on a standard small geosynchronous satellite and meets the requirements of ESA's Earth Explorer 10 call.
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    Geostare system performance assessment methodology
    (IEEE, 2016-11-03) Hobbs, Stephen E.; Convenevole, Carlo; Monti-Guarnieri, Andrea V. ; Wadge, Geoff
    Geosynchronous synthetic aperture radar (GEO SAR) is attracting growing interest due to its potential for flexible and frequent imaging over continental areas. Studies are underway to evaluate mission design options and to investigate enabling technologies. This article outlines a method for assessing mission performance which accounts for actual land-cover distributions and weather statistics to derive statistical estimates of mission performance relative to user-defined requirements. A technical challenge is to account accurately for the effects of surface “clutter”: several methods for this are available and will be evaluated. The methodology is outlined. The performance estimates will be used to refine and validate mission design options and to build evidence for the expected benefits of GEO SAR
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    Geosynchronous continental land-atmosphere sensing system (g-class): persistent radar imaging for earth science
    (IEEE, 2018-11-05) Hobbs, Stephen E.; Monti-Guarnieri, Andrea V.
    More frequent imaging of Earth system processes is recognised as one of the emerging needs in Earth observation. Conventional low Earth orbit satellites are limited in their ability to provide this, whereas satellites in geosynchronous orbit can in principle provide continuous imaging. A new mission de- sign has been developed from studies for a previous geosynchronous radar mission concept (GeoSTARe) to improve its technical feasibility and geographical coverage, and to rein- force its science focus. This new mission (Geosynchronous - Continental Land Atmosphere Sensing System (G-CLASS)) is presented. G-CLASS is in fact a family of missions: we present a version focussed on the diurnal water cycle - G-CLASS:H2O - for which geosynchronous radar has great potential. G-CLASS:H2O is being developed as a proposal for ESA’s Earth Explorer programme.
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    Meteorological OSSEs for new zenith total delay observations: impact assessment for the hydroterra geosynchronous satellite on the October 2019 Genoa event
    (MDPI, 2020-11-18) Meroni, Agostino N.; Boni, Giorgio; Pulvirenti, Luca; Monti-Guarnieri, Andrea V.; Haagmans, Roger; Hobbs, Stephen E.; Parodi, Antonio
    Along the Mediterranean coastlines, intense and localized rainfall events are responsible for numerous casualties and several million euros of damage every year. Numerical forecasts of such events are rarely skillful, because they lack information in their initial and boundary conditions at the relevant spatio-temporal scales, namely O(km) and O(h). In this context, the tropospheric delay observations (strongly related to the vertically integrated water vapor content) of the future geosynchronous Hydroterra satellite could provide valuable information at a high spatio-temporal resolution. In this work, Observing System Simulation Experiments (OSSEs) are performed to assess the impact of assimilating this new observation in a cloud-resolving meteorological model, at different grid spacing and temporal frequencies, and with respect to other existent observations. It is found that assimilating the Hydroterra observations at 2.5 km spacing every 3 or 6 h has the largest positive impact on the forecast of the event under study. In particular, a better spatial localization and extent of the heavy rainfall area is achieved and a realistic surface wind structure, which is a crucial element in the forecast of such heavy rainfall events, is modeled