Search

The Mediterranean Sea is a prominent climate-change hot spot, with many socioeconomically vital coastal areas being the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, high-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in coastal ocean observing systems worldwide, with more than half of the European sites located in the Mediterranean coastal areas. In this work, we present a review of existing HFR data multidisciplinary science-based applications in the Mediterranean Sea, primarily focused on meeting end-user and science-driven requirements, addressing regional challenges in three main topics: (i) maritime safety, (ii) extreme hazards and (iii) environmental transport process. Additionally, the HFR observing and monitoring regional capabilities in the Mediterranean coastal areas required to underpin the underlying science and the further development of applications are also analyzed. The outcome of this assessment has allowed us to provide a set of recommendations for future improvement prospects to maximize the contribution to extending science-based HFR products into societally relevant downstream services to support blue growth in the Mediterranean coastal areas, helping to meet the UN's Decade of Ocean Science for Sustainable Development and the EU's Green Deal goals., peer-reviewed

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with high-frequency radar (HFR) systems. This land-based remote sensing technology can provide, in near-real time, fine-resolution maps of the surface circulation over broad coastal areas, along with reliable directional wave and wind information. The main goal of this work is to showcase the current status of the Mediterranean HFR network and the future roadmap for orchestrated actions. Ongoing collaborative efforts and recent progress of this regional alliance are not only described but also connected with other European initiatives and global frameworks, highlighting the advantages of this cost-effective instrument for the multi-parameter monitoring of the sea state. Coordinated endeavors between HFR operators from different multi-disciplinary institutions are mandatory to reach a mature stage at both national and regional levels, striving to do the following: (i) harmonize deployment and maintenance practices; (ii) standardize data, metadata, and quality control procedures; (iii) centralize data management, visualization, and access platforms; and (iv) develop practical applications of societal benefit that can be used for strategic planning and informed decision-making in the Mediterranean marine environment. Such fit-for-purpose applications can serve for search and rescue operations, safe vessel navigation, tracking of marine pollutants, the monitoring of extreme events, the investigation of transport processes, and the connectivity between offshore waters and coastal ecosystems. Finally, future prospects within the Mediterranean framework are discussed along with a wealth of socioeconomic, technical, and scientific challenges to be faced during the implementation of this integrated HFR regional network., This study has been partially developed in the framework of the Interreg MED Strategic Project SHAREMED, co-financed by the European Regional Development Fund under the funding program Interreg MED 2014–2020. Website: https://sharemed.interreg-med.eu/ (last access: 31 March 2022). We are also grateful for the partial support of the (i) the project PO FEAMP 2014/2020 (Misura 2.51) funded by Regione Campania (Italy), (ii) the 2017 PRIN project EMME (Exploring the fate of Mediterranean microplastic: from distribution pathways to biological effects) funded by the Italian Ministry for Research (grant agreement no. 2017WERYZP), and (iii) the CMEMS-INSTAC phase II, which provides the context of the activities for HFR data harmonization, standardization, and distribution. Collaborative discussion on data management harmonization at the European level has also been carried out thanks to the contribution of the projects INCREASE (CMEMS Service Evolution Call for Tenders 21-SE-CALL1) and SeaDataCloud (EU-H2020 GA no. 730960).

The Mediterranean Sea is a prominent climate change hot spot, being their socio-economically vital coastal areas the most vulnerable targets for maritime safety, diverse met-ocean hazards and marine pollution. Providing an unprecedented spatial and temporal resolution at wide coastal areas, High-frequency radars (HFRs) have been steadily gaining recognition as an effective land-based remote sensing technology for a continuous monitoring of the surface circulation, increasingly waves and occasionally winds. HFR measurements have boosted the thorough scientific knowledge of coastal processes, also fostering a broad range of applications, which has promoted their integration in the Coastal Ocean Observing Systems worldwide, with more than half of the European sites located in the Mediterranean coastal areas. In this work, we present a review of existing HFR data multidisciplinary science-based applications in the Mediterranean Sea, primarily focused on meeting end-users and science-driven requirements, addressing regional challenges in three main topics: i) maritime safety; ii) extreme hazards; iii) environmental transport process. Additionally, the HFR observing and monitoring regional capabilities in the Mediterranean region required to underpin the underlying science and the further development of applications are also analyzed. The outcome of this assessment has allowed us to finally provide a set of recommendations for the future improvement prospects to maximize the contribution in extending the science-based HFR products into societal relevant downstream services to support the blue growth in the Mediterranean coastal areas, helping to meet the UN’s Decade of Ocean Science for Sustainable Development and the EU’s Green Deal goals.

Due to the semi-enclosed nature of the Mediterranean Sea, natural disasters and anthropogenic activities impose stronger pressures on its coastal ecosystems than in any other sea of the world. With the aim of responding adequately to science priorities and societal challenges, littoral waters must be effectively monitored with High-Frequency radar (HFR) systems. This land-based remote sensing technology can provide, in near real-time, fine-resolution maps of the surface circulation over broad coastal areas, along with reliable directional wave and wind information. The main goal of this work is to showcase the current status of the Mediterranean HFR network and the future roadmap for orchestrated actions. Ongoing collaborative efforts and recent progress of this regional alliance are not only described but also connected with other European initiatives and global frameworks, highlighting the advantages of this cost-effective instrument for the multi-parameter monitoring of the sea state. Coordinated endeavours between HFR operators from different multi-disciplinary institutions are mandatory to reach a mature stage at both national and regional levels, striving to: i) harmonize deployment and maintenance practices; ii) standardize data, metadata and quality control procedures; iii) centralize data management, visualization and access platforms; iv) develop practical applications of societal benefit, that can be used for strategic planning and informed decision-making in the Mediterranean marine environment. Such fit-for-purpose applications can serve for search and rescue operations, safe vessel navigation, tracking of marine pollutants, the monitoring of extreme events or the investigation of transport processes and the connectivity between offshore waters and coastal ecosystems. Finally, future prospects within the Mediterranean framework are discussed along with a wealth of socio-economic, technical and scientific challenges to be faced during the implementation of this integrated HFR regional network.

In this paper, a high-frequency (HF) coastal radar network is described, which is established and maintained by the Institute of Marine Sciences (ISMAR) of the National Research Council of Italy (CNR) for the measurement of surface current velocities in the Gulf of Manfredonia, located in the semienclosed Adriatic Sea (Mediterranean Sea), during 2013–2015. The network consisted of four HF radars (HFRs) that provided hourly sea surface velocity data in real-time mode in a netCDF format compliant to the Climate and Forecast Metadata Conventions CF-1.6 and the INSPIRE directive. The hourly netCDF files are disseminated via a Thematic Real-time Environmental Distributed Data Services catalog supporting OGC compliant distributions and protocols for data visualization, metadata interrogation, and data download. HFR velocity data were compared with in situ velocity measurements by Global Positioning System tracked surface drifters deployed within the radar footprint. The results show a good agreement, with the root mean square (rms) of the difference between radial velocities from HFR and drifters ranging between $20\%$ and $50\%$ of the drifter velocity rms. The HFR data have also been compared with subsurface velocity profiles from an upward looking acoustic Doppler current profiler (ADCP) during winter 2015, to gain information on the correlation between surface and water column velocities. This information is especially relevant for fishery and coastal management applications, where transport of larvae, sediments, and pollutants in the water column are considered. Results show that, at least in the considered period, the velocity in the water column is well correlated, and there is a good agreement between surface HFR and ADCP data (correlations between 0.95 and 0.75). The Gulf of Manfredonia network has been instrumental to the set up of a core of quality control practices and interoperable data and metadata formats that have been subsequently adopted within the Italian RITMARE network and that are presently discussed and refined at the European level through the projects Jerico-NEXT and INCREASE.

This report describes the governance of the European HF radar network including: the landscape of the Ocean observation networks and infrastructures, the role and links between operators of observational systems and stakeholders, the role and activities of the EuroGOOS HF radar Task Team in building a sound community strategy, the roadmap of the community with current achievements and future work lines.

The dynamics of the near-surface ocean currents result from the nonlinear interaction of simultaneous mechanisms at different scales. Of these, the submesoscale range (a few hundred meters to 10 km, hours to a few days) remains particularly challenging to observe directly, due to the high variability in both time and space. In this study, the scale-dependence of kinematic properties (divergence, vorticity and strain) in the submesoscale range, as well as their response to atmospheric forcing, is investigated in two distinct geographic regions: the Ligurian (NW-Mediterranean) Sea and the Northern Gulf of Mexico. The two applications are characterized by different dynamics, and the estimates of kinematic properties are derived from distinctly different observational approaches: in situ GPS drifters observations and remote HF radar data. The Ligurian Sea application is based on HF radar measurements obtained for the JERICO-NEXT (Joint European Research Infrastructure network for Coastal Observatory – Novel European eXpertise for coastal observaTories) and IMPACT (Port Impact on Protected Marine Areas: Cooperative Cross-Border Actions) projects. Surface current measurements span 40 km off the coast with 1.5 km resolution, available every hour. The velocity fields are used to estimate the kinematic properties with an Eulerian approach, which allows the identification of structures such as eddies and jets of the order of a few km. We focus in particular on the response of the submesoscales to an extreme wind event that was captured by the observations. The deformation of the spatial structures suggests nonlinear interactions with the wind forcing, and the kinematic properties' magnitudes are almost doubled (exceeding the Coriolis parameter, f). In the Gulf of Mexico, velocity observations are available from a series of massive, nearly simultaneous drifter releases conducted by CARTHE (Consortium for Advanced Research of Transport of Hydrocarbons in the Environment). Drifter triplets are analysed to estimate the kinematic properties of the flow at scales between 100 m and 5 km over a time scale of a day. Results show that the mean kinematic properties increase in magnitude with decreasing scales, with winter values generally higher than summer ones. For winter flows, vorticity and divergence distributions have more substantial tails of values multiple times the Coriolis paramater f at scales up to 2 km, while in the summer such large values are restricted to smaller scales (100-500 m). The Lagrangian estimates of kinematic properties obtained in the Gulf of Mexico were also compared to Eulerian estimates from concurrent X-band radar measurements, showing good correlation and validating the comparison across observational methods. Moreover, the scale-dependence of the kinematic properties from drifter triplets was found to be consistent with turbulence scaling laws evaluated as two-particle statistics. We conclude that the kinematic properties metric provides a robust complementary methodology to characterize submesoscales and can be used both with Lagrangian and Eulerian observations.

High Frequency Radar (HFR) technology refers to land based remote sensing instruments capable of measuring surface currents and ocean waves at ranges up to 200 km or more. HFR technology is widely acknowledged as a cost-efficient tool to monitor coastal regions and has potential use to monitor coastal regions all over the world. Globally, the number of HFR stations is steadily increasing. Regional networks provide real-time data in support of operational activities such as search and rescue operations, fast response in case of maritime accidents and spill of pollutants, and resource management. Each operator needs a general understanding of the working principles in order to ensure that instruments are managed properly. A set of harmonized quality assurance and quality control procedures is recommended, along with an effective approach to HFR data discovery and dissemination, to provide high quality measurements to the end users. Different documents providing best practices for operation and maintenance have emerged in the past years. They are oriented either to Direction Finding (DF) or Beam Forming (BF) systems, or to specific manufacturer’s radar systems. The main objective of this paper is to offer a comprehensive “Best Practices” document in an effort of ensuring consistency between different deployments and harmonized operations of HFR systems. This, regardless of system manufacturer, antenna design and setup. A homogeneous approach is given when possible, general concepts and definitions are introduced in order to provide a framework for both data processing and management steps. Examples are also given from the European HFR users with focus on Near Real Time data flow suitable for operational services.

Editors: Karina von Schuckmann; Pierre-Yves Le Traon.-- Review Editors: Neville Smith (Chair); Ananda Pascual; Samuel Djavidnia; Jean-Pierre Gattuso; Marilaure Grégoire; Glenn Nolan., The authors would like to thank the Institut Cartogràfic i Geològic de Catalunya (ICGC) for providing data. Thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019), through national funds., Chapter 1: Introduction and the European Environment policy framework.-- CMEMS OSR4, Chapter 2: State, variability and change in the ocean.-- CMEMS OSR4, Chapter 3: Case studies.-- CMEMS OSR4, Chapter 4: Specific events 2018.

The fundamental role of the ocean for life and well-being on Earth is more and more recognised at the highest political level. In 2015, the United Nations (UN) Sustainable Development Goals (SDGs) of the 2030 Agenda for Sustainable Development were adopted by world leaders. The SDG 14 ‘Conserve and sustainably use the oceans, seas and marine resources for sustainable development’ is dedicated to the oceans. The mention of the ocean in the Paris Agreement signed in 2016 marked a decisive milestone. In 2018, the UN Decade of Ocean Science for Sustainable Development (2021–2030) has been proclaimed (https://en.unesco.org/ocean-decade): The Intergovernmental Oceanographic Commission of UNESCO will gather ocean stakeholders worldwide behind a common framework to foster evidence-based policy-making. In fall 2019, the IPCC special report on ocean and cryosphere will be published, and will provide an opportunity to increase awareness and action before COP251 (already claimed as ‘Blue COP’).

Academic, government, and private organizations from around the globe have established High Frequency radar (hereinafter, HFR) networks at regional or national levels. Partnerships have been established to coordinate and collaborate on a single global HFR network (http://global-hfradar.org/ ). These partnerships were established in 2012 as part of the Group on Earth Observations (GEO) to promote HFR technology and increase data sharing among operators and users. The main product of HFR networks are continuous maps of ocean surface currents within 200 km of the coast at high spatial (1-6 km) and temporal resolution (hourly or higher). Cutting-edge remote sensing technologies are becoming a standard component for ocean observing systems, contributing to the paradigm shift towards ocean monitoring. In 2017 the Global HFR Network was recognized by the Joint Technical WMO-IOC Commission for Oceanography and Marine Meteorology (JCOMM) as an observing network of the Global Ocean Observing System (GOOS). In this paper we will discuss the development of the network as well as establishing goals for the future. The U.S. High Frequency Radar Network (HFRNet) has been in operation for over thirteen years, with radar data being ingested from 31 organizations including measurements from Canada and Mexico. HFRNet currently holds a collection from over 150 radar installations totaling millions of records of surface ocean velocity measurements. During the past 10 years in Europe, HFR networks have been showing steady growth with over 60 stations currently deployed and many in the planning stage. In Asia and Oceania countries, more than 110 radar stations are in operation. HFR technology can be found in a wide range of applications: for marine safety, oil spill response, tsunami warning, pollution assessment, coastal zone management, tracking environmental change, numerical model simulation of 3-dimensional circulation, and research to generate new understanding of coastal ocean dynamics, depending mainly on each country's coastal sea characteristics. These radar networks are examples of national inter-agency and inter-institutional partnerships for improving oceanographic research and operations. As global partnerships grow, these collaborations and improved data sharing enhances our ability to respond to regional, national, and global environmental and management issues.

Surface drifters and virtual particles are used to investigate transport between seven coastal regions in the central and southern Adriatic Sea to estimate the degree to which these regions function as a network. Alongshore coastal currents and cyclonic gyres are the primary circulation features that connected regions in the Adriatic Sea. The historical drifter observations span 25 years and, thus, provide estimates of transport between regions realized by the mean surface circulation. The virtual particle trajectories and a dedicated drifter experiment show that southeasterly Sirocco winds can drive eastward cross-Adriatic transport from the Italian coast near the Gargano Promontory to the Dalmatian Islands in Croatia. Southeasterly winds disrupt alongshore transport on the west coast. Northwesterly Mistral winds enhanced east-to-west transport and resulted in stronger southeastward coastal currents in the western Adriatic current (WAC) and export to the northern Ionian Sea. The central Italian regions showed strong connections from north to south, likely realized by alongshore transport in the WAC. Alongshore, downstream transport was weaker on the east coast, likely due to the more complex topography introduced by the Dalmatian Islands of Croatia. Cross-Adriatic connection percentages were higher for east-to-west transport. Cross-Adriatic transport, in general, occurred via the cyclonic sub-gyres, with westward (eastward) transport observed in the northern (southern) arms of the central and southern gyres. (C) 2016 Elsevier Ltd. All rights reserved.

Rapporto tecnico contenente il piano di implementazione dei radar, la scelta dei siti di installazione, le problematiche tecniche

Rapporto sulle attività svolte dai partner di progetto per la condivisione e interoperabilità dei dati secondo gli standard oggi in uso in Europa e nella comunità scientifica internazionale, anche alla luce delle esperienze maturate nel quadro dell'integrazione delle reti tecnologiche nell'ambito del progetto RITMARE.

This paper is an extended version of the conference paper, Marini et al., An Autonomous Imaging System for Argo Floats, IMEKO International Conference on Metrology for The Sea, 11-13 October, Naples-Italy.-- 4 pages, 4 figures, Many technologies have been developed for monitoring the ocean interior. Among them the monitoring approaches based on imaging devices are capable to disclose important data on species behaviour and spatio-temporal variations of richness and evenness. In this context, the Argo programme (http://doi.org/10.17882/42182) is a valuable instrument for monitoring the deep sea at global scale in space and time. Argo floats equipped with imaging devices are candidate to become a new monitoring tool for studying macro- and mega-fauna in large areas and for extended time periods, potentially providing monitoring results never attained before. This work summarises the results obtained on the automated fish recognition task performed on the images acquired by the GUARD1 imaging device, This work was partially supported by the TISANA project within the Argo Italy programme and by the project FixO3 (FP7/2013-2017) under the grant agreement nº 312463, through the TNA project FISHAUT

The general aim of this paper is to present a possible multidisciplinary approach to the problem of connectivity among marine protected areas (MPAs) describing some of the mechanisms and vectors that control the dispersal of propagules among spatially distributed marine communities of MPAs in the Southern Adriatic Sea. A joint approach is described that focuses on (a) measurements of surface water current and model data integrated with a dedicated software (LAVA, LAgrangian Variational Analysis), (b) measurements of rafting objects and their evaluation as an alternative way to species dispersal, and (c) a tool to automatically monitor propagules and plankton species in the water column. Studies on the dynamics of water currents demonstrated that the Gargano area has the potential to supply dispersal propagules to the Southern Adriatic both along the Italian coastline and offshore across the basin, thus providing important services to the dispersal processes and the connectivity routes among MPAs. The natural dispersion is however enhanced by floating objects, on which entire marine communities are living and travelling. The number of these objects has greatly increased with the introduction of human litter: in the Adriatic, man-made litter composes nowadays the majority (79 %) of all floating objects, with this corresponding to an almost fourfold increase in the abundance of floating objects since pre-industrial times. Such enhanced dispersion may benefit transmission of propagules from MPAs along biodiversity corridors, but may also enhance the arrival of invasive species. The direct observation of organisms can provide information on the species distribution and mobility. New technology (GUARD-1 system) has been developed to automatically identify spatial or temporal distributions of selected species in the water column by image analysis. The system has so far successfully detected blooms of ctenophores in the water column and is now being tested for identification of other zooplankton groups, such as copepods, as well as marine litter. This low-cost, long-lasting imaging system can be hosted on mobile devices such as drifters, which makes it very suitable for biological dispersal studies.

International audience; High Frequency Radar (HFR) is a land-based remote sensing instrument offering a unique insight to coastal ocean variability, by providing synoptic, high frequency and high resolution data at the ocean atmosphere interface. HFRs have become invaluable tools in the field of operational oceanography for measuring surface currents, waves and winds, with direct applications in different sectors and an unprecedented potential for the integrated management of the coastal zone. In Europe, the number of HFR networks has been showing a significant growth over the past 10 years, with over 50 HFRs currently deployed and a number in the planning stage. There is also a growing literature concerning the use of this technology in research and operational oceanography. A big effort is made in Europe toward a coordinated development of coastal HFR technology and its products within the framework of different European and international initiatives. One recent initiative has been to make an up-to-date inventory of the existing HFR operational systems in Europe, describing the characteristics of the systems, their operational products and applications. This paper offers a comprehensive review on the present status of European HFR network, and discusses the next steps toward the integration of HFR platforms as operational components of the European Ocean Observing System, designed to align and integrate Europe’s ocean observing capacity for a truly integrated end-to-end observing system for the European coasts.

Lucio Bellomo et al., High-frequency (HF) coastal radars measure current velocity at the ocean surface with a 30-100 km range and 1-3 km resolution, every 0.25-1 h. HF radars are well suited to many applications, such as search and rescue (SaR), oil-spill mitigation and ecosystem management. Here we present a first organized core of 12 HF radars installed in five sites in four countries (Greece, Italy, France and Spain) within the European MED project, the Tracking Oil Spill and Coastal Awareness (TOSCA) network. Dedicated experiments tested radar capabilities to estimate transport driven by currents, which is the key feature for all the above applications. Experiments involved the deployment of drifters, i.e., floating buoys, acting as proxies for substances passively advected by currents. Using HF radars the search range is reduced by a factor of 1.6 to 5.3 after 24 h. The paper also underlines the importance of sharing common tools for HF radar data processing and the need to mitigate radio frequency interference. The effort can be regarded as an initial step toward the creation of a Mediterranean or European HF radar network, crucial for any European integrated ocean observing system (IOOS)., This work was supported by the Tracking Oil Spills and Coastal Awareness (TOSCA) Network project [grant number 2G-MED09-425], co-financed by the European Regional Development Fund in the framework of the MED programme

The Institute of Marine Sciences (ISMAR) of the National Research Council of Italy (CNR) established a High Frequency (HF) Coastal Radar Network for the measurement of the velocity of surface currents in coastal seas. The network consists of four HF radar systems located on the coast of the Gargano Promontory (Southern Adriatic, Italy). The network has been operational since May 2013 and covers an area of approximately 1700 square kilometers in the Gulf of Manfredonia. Quality Assessment (QA) procedures are applied for the systems deployment and maintenance and Quality Control (QC) procedures are performed on the data generation pipeline. The network provides hourly sea surface velocity data in real-time mode, that are published for visualization and access. In order to produce data in interoperable formats, according to the standards of Open Geospatial Consortium (OGC) for the access and delivery of geospatial data, a netCDF architecture has been defined on the basis of the Radiowave Operators Working Group (US ROWG) recommendations and compliant to the Climate and Forecast (CF) Metadata Conventions CF-1.6. The hourly netCDF files are automatically attached to a Thematic Real-time Environmental Distributed Data Services (THREDDS) catalog supporting OGC compliant distributions and protocols for data visualization, metadata interrogation and data download. HF radar data have been validated by comparison with velocities measured by drifters deployed within the radar coverage. The data produced by the ISMAR HF radar network are presently used in a number of applications, ranging from oil spill and SAR to fishery and coastal management applications.

Forest fires in our society cause a lot of damage, in particular regarding the economic and environmental landscape. In order to monitor a large portion of territory automatically, with a good cost/performances trade-off, it is necessary to develop new early warning systems. We propose a ground-based system with modular architecture, equipped with low cost commercial sensor. The idea is to develop the software able to manage forest fire monitoring. The technique is based on static and dynamic analysis of chromatic changes between images, tailored for our case of study in a large scale monitoring of vegetation and using different sensors to reduce or eliminate the false alarm rate. Concerning theimage geo-referencing tool, the present work describes an innovative projective geo-referencing algorithm able to geo-reference complex orography regions using fixed ground station images. Besides, it does not need the collection of Ground Control Points, which is a very hard task in complex orography environments. In order to make a user oriented product and to help the operator during extinguishing activities, a decision support tool has been developed as well. This work presents the results of one year monitoring campaign conducted in cooperation with the Civil Protection Offices in Sanremo (IM), Italy

In order to optimize performances and resources operating in wildfire fighting in complex orography regions, SIRIO, an integrated monitoring system for high performance decision support has been developed. SIRIO is built up of four modules: risk forecasting, monitoring activities, image interpretation and geo-referencing and decision support products generation. The previsional evaluation of the fire risk has an addressing function on surveillance and monitoring activities. The monitoring system operates with low cost optical sensors scanning Visible, Near Infrared and Thermal Infrared bands and a high precision low cost moving system. The system is equipped with a Micro Weather Radar operating as a super gauge and is able to nowcast weather conditions. Processed data are transferred to the central server via a very flexible communication system that can operate with GPRS standards, RF links or satellite connectivity. The image interpretation modules operate on the central server performing smoke detection and hot spot identification on the basis of a tailored radiometric model. The last block of the system is responsible for processed images geo-referencing and decision support products generation. The final products are a collection of scenario images sensed in the Visible band, geo-referenced images with highlighted alarm pixels with overlaying Digital Elevation Model (DEM) levels and topographic layers containing information to be used in the case of intervention, namely a field of view on the analysed area, hot-spot positions, helicopter landing spot positions, water supply positions and intervention squad localization. Monitoring sessions can be browsed on the official SIRIO website, which allows selected access for competent operators.

Forest fires prevention, monitoring and extinguishing operations in complex orography regions present dramatic problems related to hard environmental conditions, low population density and accessibility limitations affecting interventions activities and damage assessment. In the scientific landscape, there are many existing image geo-referencing tools. They are developed in order to rectify images, which come from fixed ground station and/or satellite platforms. Some of these use satellite images to geo-reference complex orography regions and ground images to geo-referencing plane orography regions by using Ground Control Point collections. The present work describes an innovative projective geo-referencing algorithm able to geo-reference complex orography regions using a fixed ground station images. Besides, it does not need the collection of Ground Control Points, which is a very hard task in complex orography environments. The system is an innovative image geo-referencing tool conceived for decision support aid for wildfire fighting in alpine regions. The system is operating within a monitoring system in the Piedmont area (Northwestern Italy) and operates on images sensed by a fixed monitoring network. The georeferencing software operates with a geometric and projective algorithm based on a Digital Elevation Model (DEM). The algorithm is built up of three main modules: sensors lens aberration correction, field-of-view localization on DEM, image geo-referencing. As said before, the system does not need any collection of Ground Control Points to rectify images. At the output of the system, each image pixel is linked to its geographical (Lat/Lon and UTM) coordinates. The final products are: a collection of scenario images sensed in the visible band; geo-referenced images with highlighted alarm pixels with overlaying DEM levels; topographic layers containing information to be used in case of intervention. Final images contain geo-referenced information about the sensors’ field of view on the analysed area, hot-spot positions, helicopter landing spot

In the framework of an Italian Space Agency (ASI) contract, Alenia Spazio — Laben developed a new GPS radio occultation receiver: the ROSA receiver. It will manage both “rise” and “set” occultation events, tracking signals coming from the stratosphere in closed-loop and switching to the open-loop when they emerge from the troposphere. It is well known that the open-loop signal tracking needs a good Excess-Doppler prediction, and that it has to be evaluated in advance (and in quasi real time) by the occultation on-board software. The adopted prediction strategy is a simplified and optimized version of the technique suggested by Sokolovskiy (2001). This work provides the results of the validation of this technique, carried on through comparisons with about 200 Excess-Doppler observations collected by the CHAMP Radio Occultation GPS receiver during the winter season 2002/2003 above Europe. Some insights about the prediction of the end occultation time for setting events (or start occultation time for rising events) are also given. The strategy implemented by the on-board ROSA occultation manager for the open-loop tracking is quickly introduced. Also a mountain top measurement campaign with the ROSA breadboard receiver is discussed. It is planned for 2006. This experiment is encouraged by ASI in order to test and to validate the ROSA tracking capabilities and the algorithms necessary for the extraction of the GPS occultation observables from raw data.

The TRMM Precipitation Radar (TPR) can be used to adjust Ground-based Radar (GR) data, as a function of the range from the GR site. The analysis is based on the average, linear radar reflectivity in circular rings around the GR site for both GR and TPR images. The GR/TPR ratio varies, for the Cyprus radar, on average from approximately −1 dB, at 20 km, to −10 dB at 105 km. For the Israeli radar, it varies from approximately −4 dB, at 20 km, to −7 dB at 105 km. The average departure at the average range is considered to be mainly caused by the calibration of the GR. The range dependence is interpreted to be caused by the increasing sampling volume of the GR with range (overshooting, vertical profile of reflectivity and non- homogeneous beam filling).