Andrea Gatti

Flooding is one of the most frequent natural disasters worldwide, resulting in substantial socioeconomic losses and public health threats. The EASTERN project proposes an innovative approach exploiting Artificial Intelligence (AI) techniques to combine data collected from Synthetic Aperture Radar (SAR) imaging and ground measurements for real-time...

This paper presents an experimental study on the integration of the fifth generation (5G) cellular networks and the Global Navigation Satellite System (GNSS) for positioning. Along with the use of experimental data collected from both 5G and GNSS deployed technologies, the novelty of this research includes the design of a Bayesian tracking methodol...

A comprehensive analysis of the July 2021 event that occurred on Lake Como (Italy), during which heavy hailstorms and floods affected the surroundings of Lake, is presented. The study provides a detailed analysis of the event using different observation sources currently available. The employed techniques include both conventional (rain gauges, rad...

In this article, we report the first investigation over time of the atmospheric conditions around terrestrial gamma-ray flash (TGF) occurrences, using GPS sensors in combination with geostationary satellite observations and ERA5 reanalysis data. The goal is to understand which characteristics are favorable to the development of these events and to...

In this article we report the first investigation over time of the atmospheric conditions around TGFs occurrence, using GPS sensors in combination with geostationary satellite observations and ERA5 reanalyses data. The goal is to understand which characteristics are favourable to the development of these events and to investigate if any precursor s...

The tropospheric delay is an essential source of error for positioning using the Global Navigation Satellite System (GNSS). Scientific applications of GNSS positioning such as the study of earth crust deformation and earthquake prediction require high accuracy in positioning, an analysis of tropospheric delay calculations is needed to improve the a...

The use of low-cost GNSS stations for meteorological applications requires the modeling of ionospheric errors. Although low-cost dual-frequency receivers are now available, current ones are still missing the L2 frequency and this prevents the availability of iono-free observations. This second frequency can be predicted by exploiting dual-frequency...

Atmospheric Phase Screens (APSs) derived from Interferometric Synthetic Aperture Radar (InSAR) observations contain the difference between the tropospheric water-vapor-induced delay of two acquisition epochs, i.e., the slave and the master (or reference) epochs. Using estimates of the atmospheric state coming from independent sources, for example n...

A prototype of a low-cost GNSS (Global Navigation Satellite System) monitoring system was installed on a deep-seated landslide in northwestern Slovenia to test its performance under field conditions. The system consists of newly developed GNSS stations based on low-cost, dual-frequency receivers and open-source GNSS processing software. It automati...

A Synthetic Aperture Radar can offer not only an accurate monitoring of the earth surface deformation, but also information on the troposphere, such as the total path delay or the columnar water vapor at high horizontal resolution. This can be achieved by a proper interferometric processing and post-processing of the radar interferograms. The fine...

Multipath mitigation approach implemented in goGPS. This presentation is a modified version of the previous presented in Luxembourg, here with improved descriptions and new figures for the EGU2020 General Assembly. The strategy uses Zernike polynomials interpolation and high-resolution gridding to compute multipath maps from the residuals of the G...

Receiver antenna calibration plays an important role in precise point positioning (PPP). Correct management of multipath effects can improve the estimation of tropospheric parameters and the stability of the coordinates over short measurement sessions. In the years, many techniques have been developed to mitigate multipath effects, among them multi...

The Mediterranean region is frequently struck by severe rainfall events causing numerous casualties and several million euros of damages every year. Thus, improving the forecast accuracy is a fundamental goal to limit social and economic damages. Numerical Weather Prediction (NWP) models are currently able to produce forecasts at the km scale grid...

Global Navigation Satellite System (GNSS) have been routinely used in the last decades to estimate water vapor content in the lower part of the atmosphere. Water vapor measurements have been successfully integrated in Numerical Weather Prediction (NWP) models, showing a positive impact on the forecast of rain events. Since few years, it is possible...

Goal of the project was to investigate whether the assimilation of high resolution Earth Observation variables improve the forecast of heavy rain events. Several experiments were conducted assimilating soil moisture, surface wind, sea surface temperature, land surface temperature and zenith total delay. The assimilation of wind and water vapor cont...

The new version of the open-source goGPS MATLAB software has been written to be a simple tool to perform efficient analysis of GNSS data from both geodetic and low-cost receivers. With its capability to download automatically all the resources needed by the selected algorithms, the relative easiness of use, and its flexibility with the possibility...

The activities carried out within the WP2 of the TWIGA-H2020 project are described. In particular, the following topics are covered: the definition of a new low-cost GNSS receiver network to be soon installed in Uganda, a new algorithm for the retrieval of water vapor maps from Sentinel-1 data and the ongoing numerical weather prediction experiment...

GNSS atmospheric water vapor monitoring is not yet routinely performed in Italy, particularly at the regional scale. However, in order to support the activities of regional environmental protection agencies, there is a widespread need to improve forecasting of heavy rainfall events. Localized convective rain forecasts are often misplaced in space a...

The STEAM (SaTellite Earth observation for Atmospheric Modelling) project, funded by the European Space Agency, aims at investigating new areas of synergy between high-resolution numerical weather prediction (NWP) models and data from spaceborne remote sensing sensors. An example of synergy is the incorporation of high-resolution remote sensing dat...

goGPS is a GNSS processing software written in MATLAB, that was originally developed for precise positioning purposes, mainly based on the double-difference relative approach. To broaden its use by including also tropospheric delay estimation, all the algorithms and procedures needed to apply PPP (Precise Point Positioning) were implemented. In add...

Regional gravity field modelling by means of remove - restore procedure is nowadays widely applied to predict grids of gravity anomalies in exploration geophysics. Considering this application, due to the required accuracy and resolution, airborne gravity observations are generally adopted. In this work a procedure to filter and grid raw airborne o...

Regional gravity field modelling by means of remove-compute-restore procedure is nowadays widely applied in different contexts: it is the most used technique for regional gravimetric geoid determination, and it is also used in exploration geophysics to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.), which are useful to unde...

The fifth release of the space-wise approach, as well as the ones of the direct and time-wise approaches, is based on the processing of the whole GOCE dataset, from November 2009 to October 2013. It consists in global grids of gravity gradients at 0.2°x0.2° spatial resolution and in a spherical harmonic model derived from these grids by a discretiz...

Beside the traditional modelling of the Earth gravity field in terms of truncated spherical harmonic expansion, the final products of the GOCE mission include also grids of gravity gradients at satellite altitude, like for example the ones computed by the space-wise approach in the framework of the High-level Processing Facility (HPF). This is moti...

Beside the traditional modelling of the Earth gravity field in terms of truncated spherical harmonic expansion, the final products of the GOCE mission include also grids of gravity gradients at satellite altitude, like for example the ones computed by the space-wise approach in the framework of the High-level Processing Facility (HPF). This is moti...

GOCE data covering the mission phase at nominal satellite altitude (about 250 km) have been processed by the space-wise approach according to the new strategy for the production of global grids of gravity gradient gradients at 0.2°x0.2° resolution. The crucial points of the method are the filtering along the orbit in order to reduce variance and co...

goGPS is a free and open source software package designed to enhance the accuracy of single frequency low-cost GPS devices by employing an extended Kalman filter. This filter can be applied either in post-processing or in real-time and it is specifically tailored for addressing the issues related to low-cost GPS receivers. To further enhance the ac...

The new release of the ESA-GOCE data set, with improved calibration and processing, has been attacked by the space-wise approach according to a new strategy for the data gridding at satellite level. Two approaches are possible: the first exploiting the creation of about 30 global grids of 1,620,000 values, each corresponding to about 2 months of da...

Riassunto L'obiettivo principale della missione satellitare GOCE dell'Agenzia Spaziale Europea (ESA) è la stima del campo gravitazionale terrestre con elevata accuratezza e risoluzione spaziale. Questa stima è solitamente espressa come una serie troncata di armoniche sferiche. Agli utenti vengono forniti i coefficienti della serie e la descrizione...

The global height datum problem, that is the determination of biases of different height systems at global scale, is revised and two solutions are proposed. As it is well known, biased heights enter into the computation of terrestrial gravity anomalies, which in turn are used for geoid determination. Hence, these biases enter as secondary or indire...

The main objective of the GOCE mission is to estimate the Earth gravity field from satellite data with high accuracy and resolution. This estimate is expressed by a truncated series of spherical harmonics, providing users with the series coefficients and their full error covariance matrix. This model, projecting the unknown potential on a finite gl...

Regional height systems do not refer to a common equipotential surface, such as the geoid. They are usually referred to the mean sea level at a reference tide gauge. As mean sea level varies (by ±1 to 2 m) from place to place and from continent to continent each tide gauge has an unknown bias with respect to a common reference surface, whose determ...

The global height datum problem, namely the determination of biases of different height systems referred to different origins (i.e. to different equipotential surfaces), is typically reduced to a least squares systems where GPS derived ellipsoidal heights are compared with orthometric heights and geoid undulations derived from suitable global model...

In the framework of the GOCE data analysis, the space-wise approach implements a multi-step collocation solution for the estimation of a global geopotential model in terms of spherical harmonic coefficients and their error covariance matrix. The main idea is to use the collocation technique to exploit the spatial correlation of the gravity field in...

Riassunto Il modello globale del campo di gravità terrestre calcolato con l'approccio space-wise è una delle tre soluzioni ufficiali rilasciate dall'ESA dall'analisi dei dati GOCE. Il modello consiste in una serie di coefficienti dello sviluppo in armoniche sferiche e nella corrispondente matrice di covarianza dell'errore di stima. La principale ca...

The global gravity field model computed by the space- wise approach is one of three official solutions delivered by ESA from the analysis of the GOCE data. The model consists of a set of spherical harmonic coefficients and the corresponding error covariance matrix. The main idea behind this approach is to exploit the spatial correlation of the grav...

The space-wise approach is a multi-step collocation procedure, developed in the framework of the GOCE HPF data processing for the estimation of the spherical harmonic coefficients of the Earth gravitational field and their error covariance matrix. The main idea of the space-wise approach is to perform this estimation by exploiting the spatial corre...

Riassunto Dal 29 settembre 2009 il satellite GOCE è in modalità operativa e sta inviando a terra i dati acquisiti dagli strumenti a bordo, in particolare le derivate seconde del potenziale gravitazionale osservate dal gradiometro elettrostatico e i dati di tracciamento dell'orbita raccolti dal ricevitore GPS. Il processamento basato sull'approccio...