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In the past twenty years, satellite gravimetry missions have successfully provided data for the determination of the Earth static gravity field (GOCE) and its temporal variations (GRACE and GRACE-FO). In particular, the possibility to study the evolution in time of Earth masses allows us to monitor global parameters underlying climate changes, water resources, flooding, melting of ice masses and the corresponding global sea level rise, all of which are of paramount importance, providing basic data on, e.g. geodynamics, earthquakes, hydrology or ice sheets changes. Recently, a large interest has developed in novel technologies and quantum sensing, which promise higher sensitivity, drift-free measurements, and higher absolute accuracy for both terrestrial surveys and space missions, giving direct access to more precise long-term measurements. Looking at a time frame beyond the present decade, in the MOCAST+ study (MOnitoring mass variations by Cold Atom Sensors and Time measures) a satellite mission based on an “enhanced” quantum payload is proposed, with cold atom interferometers acting as gravity gradiometers, and atomic clocks for optical frequency measurements, providing observations of differences of the gravitational potential. The main outcomes are the definition of the accuracy level to be expected from this payload and the accuracy level needed to detect and monitor phenomena identified in the Scientific Challenges of the ESA Living Planet Program, in particular Cryosphere, Ocean and Solid Earth. In this paper, the proposed payload, mission profile and preliminary platform design are presented, with end-to-end simulation results and assessment of the impact on geophysical applications.

The Italian space industry, and specifically Leonardo S.p.A., has gained unique skills at an international level in the development of space-qualified power laser sources with for lidar Earth observation applications (Aeolus, EarthCARE). Moreover, Leonardo S.p.A. and the Italian optical industry, has a consolidated technical-scientific knowledge and consolidated experience in the design and development of lidar receiver sub-systems (telescopes, optical devices and sensors) with space applications. The Italian Space Agency (ASI) intends to benefit from long-term expertise to design and develop a lidar system for Earth observation applications. Two separate feasibility studies, one focusing of technical aspects and one focusing on scientific aspects, are presently underway to define mission goals and a possible instrument layout.CALIGOLA has a primary focus on the atmosphere, but also a strong focus on the study of the Ocean-Earth-Atmosphere system and the mutual interactions within it. Exploiting the three Nd: YAG laser emissions at 354.7, 532 and 1064 nm and the elastic (Rayleigh-Mie) and Raman lidar echoes from atmospheric constituents, CALIGOLA is conceived to carry out three-wavelength particle backscatter and depolarization ratio and two-wavelength particle extinction profile measurements from aerosols and clouds to be used to retrieve their microphysical and dimensional properties. Furthermore, measurement of the elastic backscattered echoes from the sea surface and the underlying layers, and their degree of depolarization, CALIGOLA will be exploited to characterize sea optical properties (ocean color) and the suspended particulate matter, which are needed to study the seasonal and inter-annual phytoplankton dynamics and to improve the understanding of the role of phytoplankton in marine biogeochemistry, in the global carbon cycle and in the response of marine ecosystems to climate variability. A specific measurement channel will be dedicated to fluorescence measurements from atmospheric aerosols and marine chlorophyll, for the purpose of aerosol typing and for characterizing ocean primary production. Aerosol fluorescence measurements at 680 nm/460 nm are also planned for the purpose of aerosol typing. CALIGULA will also allow accurate measurements of the small-scale variability of the earth's surface elevation primarily associated with variations in the terrain, vegetation and forest canopy height.The CALIGOLA project is explicitly included the on-going Three-Year Activity Plan (2021-2023) of the Italian Space Agency, with a scheduled tentative launch window of 2026-2028. The considered strategy to develop the above described space lidar mission in such a short time relies on the maximum exploitation of subsystems already developed at national level for space applications, with a high TRL (TRL>7), ultimately leading to a space mission with high impact and scientific timeliness. The Phase A study of the technological feasibility of the laser source is on-going, commissioned by ASI to Leonardo S.p.A., and scientific studies in support of the mission also on-going, with the University of Basilicata being the leading scientific institution. The Italian Space Agency is willing to pursue this mission in a coordinated way with one or more other European or extra-European Space Agencies, with a bilateral or multi-lateral contributed mission approach, and, in this regard, any interest from other Agencies is welcome and desired.

This contribution describes the Trigger board of the High-Energy Particle Detector, which will be placed onboard the second China Seismo-Electromagnetic Satellite for CSES-Limadou mission. This mission will monitor variations in ionospheric parameters that are supposed to be related to earthquakes. The first satellite is already in orbit and the second one will be launched in 2023. The HEPD detector will be composed by a tracker made of CMOS sensors (ALPIDE sensors), followed by two segmented planes of plastic scintillators used for trigger signals generation. The actual calorimeter will be composed by twelve planes of plastic scintillator and two segmented planes of an inorganic scintillator called LYSO. The calorimeter is surrounded by five scintillator planes used as a veto system. All the scintillators are coupled with PMTs, whose signals are acquired and digitized by the Trigger board, that also implements the trigger system for the whole apparatus. The ongoing work on the Trigger board consists in the design of both the hardware and the firmware used for the communication with the other boards of the detector, power managing, and the interfacing with the ASIC used for PMTs’ readout. Eventually the Trigger board will be tested to verify its functionalities and its compliance with the HEPD design specifications. Next developments are the integration of the Trigger board with the other systems on the detector and the environmental testing of the whole system.

Both GRACE and GOCE have proven to be very successful missions, providing a wealth of data which are exploited for geophysical studies such as climate changes, hydrology, sea level changes, solid Earth phenomena, with benefits for society and the whole world population. It is indispensable to continue monitoring gravity and its changes from space, so much so that a GRACE follow-on mission has been launched in 2018. In this paper, a new satellite mission concept named MOCASS is presented, which can be considered as a GOCE follow-on, based on an innovative gradiometer exploiting ultra-cold atom technology and aimed at monitoring Earth mass distribution and its variations in time. The technical aspects regarding the payload will be described, illustrating the measurement principle and the technological characteristics of a cold atom interferometer that can measure gravity gradients. The results of numerical simulations will be presented for a one-arm and a two-arm gradiometer and for different orbit configurations, showing that an improvement with respect to GOCE could be obtained in the estimate of the static gravity field over all the harmonic spectrum (with an expected error of the order of 1 mGal at degree 300 for a 5-year mission) and that estimates are promising also for the time-variable gravity field (although GRACE is still performing better at very low degrees). Finally, the progress achievable by exploiting MOCASS observations for the detection and monitoring of geophysical phenomena will be discussed: the results of simulations of key geophysical themes (such as mass changes due to hydrology, glaciers and tectonic effects) with expected gravity change-rates, time constants and corresponding wavelengths, show that an improvement is attainable and that signals invisible to past satellites could be detected by exploiting the cold atom technology.

During the August 25, 2018 geomagnetic storm, the new borne CSES-01 satellite and the Swarm A satellite detected a really large equatorial plasma bubble (EPB) in the post-midnight sector over western Africa. We investigated the features of this deep ionospheric plasma depletion using data from the Langmuir probes on-board CSES-01 and Swarm A satellites, and data from the high-precision magnetometer and the electric field detector instruments on-board CSES-01. Using also plasma and magnetic field data from THEMIS-E satellite we found that, during the passage of the magnetic cloud that drove the geomagnetic storm, an impulsive variation lasting about ten minutes characterized the solar wind (SW) pressure. The analysis of the delay time, between the occurrence of such impulsive variation and the detection of the plasma bubble, suggests a possible link between the SW pressure impulsive variation as identified by THEMIS-E and the generation of the EPB as detected by CSES-01 and Swarm A. We put forward the hypothesis that the SW pressure impulsive variation might have triggered an eastward prompt penetrating electric field that propagated from high to equatorial latitudes, overlapping in the nightside region to the zonal westward electric field, causing either a reduction or an inversion, at the base of the EPB triggering.

On 25 August 2018, a G3-class geomagnetic storm reached the Earth’s magnetosphere, causing a transient rearrangement of the charged particle environment around the planet, which was detected by the High-Energy Particle Detector (HEPD) on board the China Seismo-Electromagnetic Satellite (CSES-01). We found that the count rates of electrons in the MeV range were characterized by a depletion during the storm’s main phase and a clear enhancement during the recovery caused by large substorm activity, with the key role played by auroral processes mapped into the outer belt. A post-storm rate increase was localized at L-shells immediately above ∼3 and mostly driven by non-adiabatic local acceleration caused by possible resonant interaction with low-frequency magnetospheric waves.

Recently, the Italian Space Agency (ASI) and the Jet Propulsion Laboratory (JPL) have agreed to carry out a joint study for an Earth Observation scientific mission in the infrared spectral range (MWIR-LWIR). A mission of this type is considered of high priority by the NASA's “Decadal Survey” plan, as well as being one of the priorities of the future Sentinel of the Copernicus program. Furthermore, an MWIR-LWIR system with spatial resolutions better than 90 m (target 50 m) could represent a formidable integration of the observational capacity of the ASI PRISMA and SHALOM missions, as it would allow observing the entire wavelength range from Visible to thermal IR and consequently expanding the spectrum of scientific applications of the national satellite system. INGV in 2018–2019 in the frame of ASI contract has carried out a review of scientific and technical requirements for a new EO “Thermal Mission” which my support a large number of applications.

The aim of this paper is to address the monitoring of the recovery phase in the aftermath of Hurricane Matthew (28 September–10 October 2016) in the town of Jérémie, southwestern Haiti. This is accomplished via a novel change detection method that has been formulated, in a data fusion perspective, in terms of multitemporal supervised classification. The availability of very high resolution images provided by last-generation satellite synthetic aperture radar (SAR) and optical sensors makes this analysis promising from an application perspective and simultaneously challenging from a processing viewpoint. Indeed, pursuing such a goal requires the development of novel methodologies able to exploit the large amount of detailed information provided by this type of data. To take advantage of the temporal and spatial information associated with such images, the proposed method integrates multisensor, multisource, and contextual information. Markov random field modeling is adopted here to integrate the spatial context and the temporal correlation associated with images acquired at different dates. Moreover, the adoption of a region-based approach allows for the characterization of the geometrical structures in the images through multiple segmentation maps at different scales and times. The performances of the proposed approach are evaluated on multisensor pairs of COSMO-SkyMed SAR and Pléiades optical images acquired over Jérémie, in the aftermath of and during the three years after Hurricane Matthew. The effectiveness of the change detection results is analyzed both quantitatively, through the computation of accuracy measures on a test set, and qualitatively, by visual inspection of the classification maps. The robustness of the proposed method with respect to different algorithmic choices is also assessed, and the detected changes are discussed in relation to the recovery endeavors in the area and ground-truth data collected in the field in April 2019.

Globally, 800 million people live within 100 km of a volcano thought to have been active in the last 10,000 years. The basis of forecasting the short term progression of volcanic unrest or onset of eruption is high quality monitoring data, ideally analysed in near real time consistently over long time periods. Volcanic deformation – the displacement of the Earth's surface in response to magmatic or volcanic processes – forms the foundation of many monitoring streams in combination with measurements of seismicity and gas emission. At present, < 10% of Holocene volcanoes are monitored routinely, while up to 45% are not monitored at all.

The radiation belts in the Earth’s magnetosphere pose a hazard to satellite systems and spacecraft missions (both manned and unmanned), heavily affecting payload design and resources, thus resulting in an impact on the overall mission performance and final costs. The NASA AE9/AP9/SPM radiation models for energetic electrons, protons, and plasma provide useful information on the near-Earth environment, but they are still incomplete as to some features and, for some energy ranges, their predictions are not based on a statistically sufficient sample of direct measurements. Therefore, it is of the upmost importance to provide new data and direct measurements to improve their output. In this work, the AP9 model is applied to the China Seismo-Electromagnetic Satellite (CSES-01) orbit to estimate the flux of energetic protons over the South Atlantic Anomaly during a short testing period of one day, 1 January 2021. Moreover, a preliminary comparison with proton data obtained from the High-Energy Particle Detector (HEPD) on board CSES-01 is carried out. This estimation will serve as the starting ground for a forthcoming complete data analysis, enabling extensive testing and validation of current theoretical and empirical models.

Agencies from CEOS (Committee on Earth Observation Satellites) have traditionally focused their efforts on the response phase. Rapid urbanization and increased severity of weather events has led to growing economic and human losses from disasters, requiring international organisations to act now in all disaster risk management (DRM) phases, especially through improved disaster risk reduction policies and programmes. As part of this effort, CEOS agencies have initiated a series of actions aimed at fostering the use of Earth observation (EO) data to support disaster risk reduction and at raising the awareness of policy and decision-makers and major stakeholders of the benefits of using satellite EO in all phases of DRM. CEOS is developing a long-term vision for sustainable application of satellite EO to all phases of DRM. CEOS is collaborating with regional representatives of the DRM user community, on a multi-hazard project involving three thematic pilots (floods, seismic hazards and volcanoes) and a Recovery Observatory that supports resilient recovery from one major disaster. These pilot activities are meant as trail blazers that demonstrate the potential offered by satellite EO for comprehensive DRM. In the framework of the 2015 3rd World Conference on Disaster Risk Reduction (WCDRR), the CEOS space agencies intend to partner with major stakeholders, including UN organizations, the Group on Earth Observations (GEO), international relief agencies, leading development banks, and leading regional DRM organisations, to define and implement a 15-year plan of actions (2015- 2030) that responds to high-level Post-2015 Framework for Disaster Risk Reduction priorities. This plan of action will take into account lessons learned from the CEOS pilot activities.

Within Latin America, about 319 volcanoes have been active in the Holocene, but 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) developed a 4-year pilot project (2013-2017) to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring as well as with the international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). The goal is to make sure that the most useful data are collected at each volcano following the guidelines of the Santorini report that observation frequency is related to volcano activity, and to communicate the results to the local institutions in a timely fashion. Here we highlight how coordinated multi-satellite observations have been used by volcano observatories to monitor volcanoes and respond to crises. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR), which have been used in conjunction with other observations to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. During this time period, we find 26 volcanoes deforming, including 18 of the 28 volcanoes that erupted – those eruptions without deformation were less than 2 on the VEI scale. Another 7 volcanoes were restless and the volcano observatories requested satellite observations, but no deformation was detected. We describe the lessons learned about the data products and information that are most needed by the volcano observatories in the different countries using information collected by questionnaires. We propose a practical strategy for regional to global satellite volcano monitoring for use by volcano observatories in Latin America and elsewhere to realize the vision of the Santorini report. Por pares

Swell propagation in shallow water sets specific relationships between water depth and swell parameters like swell wavelength and period. These relationships allow coastal bathymetry to be retrieved if swell parameters are measured. Synthetic aperture radar (SAR) is able to image swell waves, and spectral analysis of SAR images is a well-known approach for measuring swell parameters. However, owing to nonlinearities in SAR imaging, speckle and noise, spectral analysis can result in significant bathymetric errors. The paper individuates the conditions in which linear imaging is achieved and presents an algorithm able to preserve the accuracy of the calculated bathymetry against image speckle and noise. The proposed approach includes: 1) image resizing and filtering before spectral analysis; 2) limitations to the domain of the spectral analysis; and 3) spatial smoothing of the estimated parameters. The algorithm is tested on L-band ALOS PALSAR data collected over coastal regions in the Gulf of Naples, Italy, showing that swell can be properly tracked from open sea to shoreline. Dense coverage and submetric accuracy is thus achieved.

The use of synthetic aperture radar (SAR) data is presently well established in operational services for flood management. However, some events might be missed because of the limited area that can be observed through a SAR image and the need of programming SAR acquisitions in advance. To tackle these problems, it is possible to setup a system that is able to trigger the SAR acquisitions based on flood forecasts and to take advantage of the various satellite SAR sensors that are presently operating. On behalf of the Italian Civil Protection Department (DPC), a prototype of this kind of system has been setup and preliminary tested, using COSMO-SkyMed (CSK) and Sentinel-1 (S-1) data, to monitor the Po River (Northern Italy) flood occurred in November 2014. This paper presents the prototype system and describes in detail the near real-time flood mapping algorithm implemented in the system. The algorithm was previously developed to classify CSK images, and is modified here in order to be applied to S-1 data too. The major outcomes of the monitoring of the Po River flood are also analyzed in this paper, highlighting the importance of the in advance programming of the radar acquisitions. Results demonstrate the reliability of the flood predictions provided by the model and the accuracy of the flood mapping algorithm. It is also shown that, when CSK and S-1 data are simultaneously acquired, their joint use allows for an interpretation of some ambiguous radar signatures in agricultural areas.

COnstellation of small Satellites for Mediterranean basin Observation (COSMO-SkyMed) is the largest Italian investment in Space Systems for Earth Observation, commissioned and funded by Italian Space Agency (ASI) and Italian Ministry of Defence (MoD). COSMO-SkyMed is a Dual-Use (Civilian and Defence) end-to-end Earth Observation System aimed at establishing a global service supplying provision of data, products and services compliant with well-established international standards and relevant to a wide range of applications, such as Risk Management, Scientific and Commercial Applications and Defence Applications. The system consists of a constellation of four LEO mid-sized satellites, each equipped with a multi-mode high-resolution SAR operating at X-band. Three out of four COSMO-SkyMed satellites have been successfully launched the 8th of June, the 9th of December 2007 and the 25th of October 2008 respectively, while the remaining satellite will be deployed within 2010. COSMO-SkyMed 1 and 2 completed their commissioning phase to test, verify and qualify the overall system and from the 1st of August 2008 both satellites are in the operational phase. The third satellite is still performing its commissioning and it is expected to enter in operation in the second half of 2009. The results of the commissioning phase of COSMO-SkyMed 1 and 2 are presented together with the Scientific Mission Exploitation strategy (i.e. Announcement of Opportunity, Background Mission).

This paper describes two examples of synergistic management of EO based services for flood emergency monitoring. The first relates to the benefits of collaboration between decision makers, end users and experts reporting the case of the November 2014 Liguria and Po River flooding, when early activation, prior to the occurrence of the flood, was made possible and the second shows the benefits of the synergy between Sentinel-1 (S-1) and COSMO-SkyMed (CSK) contributing missions for monitoring floods at national scale. The two examples are referred to flood monitoring but the conclusions can be easily extended to other risks.

Long gravity waves or swell dominating the sea surface is known to be very useful to estimate seabed morphology in coastal areas. The paper reviews the main phenomena related to swell waves propagation that allow seabed morphology to be sensed. The linear dispersion is analysed and an error budget model is developed to assess the achievable depth accuracy when Synthetic Aperture Radar (SAR) data are used. The relevant issues and potentials of swell-based bathymetry by SAR are identified and discussed. This technique is of particular interest for characteristic regions of the Mediterranean Sea, such as in gulfs and relatively close areas, where traditional SAR-based bathymetric techniques, relying on strong tidal currents, are of limited practical utility.

The increasing interest on electron emission properties of thin carbon films with different percentages of sp(3) and sp(2) configurations, and/or with different space domain or dimension of carbon clusters, stimulated a lot of research activities also in the preparation methods, more suitable to deposit thin films with optimised electronic characteristics. The aim of our work is to explore the possibility of depositing films, by pulsed laser deposition (PLD) (Nd:YAG, lambda = 532 nm), with controlled percentage of sp(3)/sp(2) carbon component or even with nanoscopic structure, introducing an ancillary energy source, coming from the presence of plasma-activated species, obtained by a radio frequency system, in the proximity of the substrate. The results obtained by the plasma activated PLD method are compared with those obtained by a plain PLD, working under the same experimental conditions (fluence, pressure, inert buffer gases). The substrate temperature was varied from room temperature up to similar to750 degreesC, to ascertain its influence on the microstructure evolution. Micro-Raman spectra show significant variations as a function of substrate temperature and RF-plasma activation. The results are correlated with surface morphology modifications followed by SEM spectroscopy.

The present paper reports on some insights in the use of Synthetic Aperture Radars (SAR) for bathymetric data retrieval by exploiting variation in swell wave parameters approaching the shoreline. Since SAR signals are unable to penetrate sea surface and to reach seabed, echoed signals from sea surface are used to investigate underwater bathymetry in coastal area. A suitable data processing methodology is proposed to properly detect swell shoaling and refraction phenomena, and to accurately measure swell parameters. The described methodology is tested by using ALOS L-band SAR images over the Gulf of Naples, Italy. A Digital Elevation Model (DEM) of the investigated area is thus obtained. Results are consistent with the values reported in the Official Nautical Chart provided by the Italian Navy Hydrographic Institute.

Surface current variations generated by underwater bottom topography produce intensity modulations in SAR images. The direct inversion from image intensity to bathymetry is difficult, in general, because of the theoretical complexity of the involved physical mechanisms and the practical consideration that most of the required parameters cannot be derived from SAR data. The conventional approach for SAR bathymetry relies on the forward mechanism, i.e. the simulation of SAR images from (partially) known bottom topography and, then, the adjustment of the bathymetry through iterative comparison between simulated and collected images. The present paper deals with the development of a bathymetric SAR algorithm able to perform the direct inversion limiting the need for a-priori information or in-situ measurements, and for human intervention in the processing chain. The proposed approach is tested on COSMO-SkyMed data collected over coastal regions in the Gulf of Naples, showing that dense coverage and metric accuracy can be achieved even when the current is not enough strong to dominate SAR response.

A simplified algorithm for SAR-based bathymetry is presented able to measure surface current variations generated by the bottom topography from SAR intensity images and to reduce the need for both a-priori information and human-inthe- loop operations. The algorithm is first analyzed from a theoretical point of view and an error budget model is developed to estimate the achievable depth accuracy as a function of the uncertainty in the input parameters. Preliminary experimental results are also presented in which the algorithm is applied to both COSMO-SkyMed and ALOS images of the Gulf of Naples. The results show that the technique has the potential to generate depth measures that are significantly denser than those commonly reported in the nautical charts.