Rene Garello

Rene Garello
IMT Atlantique | IMT · Division of Information and Communication Technologies

About

116
Publications
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Publications

Publications (116)
Article
Full-text available
Air pollution and sea pollution are both impacting human health and all the natural environments on Earth. These complex interactions in the biosphere are becoming better known and understood. Major progress has been made in recent past years for understanding their societal and environmental impacts, thanks to remote sensors placed aboard satellit...
Article
Full-text available
Knowledge of ocean surface current at high resolutions is crucial for many applications. In addition to the classic satellite altimetry retrieval from Sea Surface Height (SSH), ocean surface currents can be retrieved from Sea Surface Temperature (SST) observations using a transfer function between SST and SSH. Previous works showed the potential of...
Research Proposal
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Please follow that link: https://www.gstss.org/2019_Brest/ and join us !!!
Article
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Maximenko et al. Integrated Marine Debris Observing System Plastics and other artificial materials pose new risks to the health of the ocean. Anthropogenic debris travels across large distances and is ubiquitous in the water and on shorelines, yet, observations of its sources, composition, pathways, and distributions in the ocean are very sparse an...
Article
Full-text available
The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planet’s ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing...
Article
Full-text available
The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planet's ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing...
Conference Paper
Massive and rapidly increasing use of plastics in modern society with short average use times and poor reuse and recycling options has resulted in a global threat with potentially devastating impacts on human and non-human life. Knowledge on the impacts of plastics in all forms on the planetary life-support system is rapidly accumulating and it und...
Conference Paper
Full-text available
The surveillance of the maritime traffic is a major issue for security and monitoring issues. Spaceborne technologies, especially satellite AIS ship tracking and high-resolution imaging, open new avenues to address these issues. Current operational systems cannot fully benefit from the available and upcoming multi-source data streams. In this conte...
Article
Full-text available
The surveillance of illegal fishing activities is a critical issue for the management of marine resources. In this study, we investigate the space-based monitoring of fishing vessel activities using vessel monitoring system (VMS) trajectory data. Our specific objective is the automatic recognition of the employed fishing gear type from VMS data. Th...
Conference Paper
This study addresses the use of the Holder moments for ship detection from SAR dual polarization data. In the proposed methodology we first merge the two images from the dual polarization data and then perform the detection. The discrimination between the vessel samples and the ones of the sea clutter is achieved via a joint PDF of the geometric an...
Conference Paper
The potentiality of retrieving high spatial resolution velocity fields by exploiting the synergy between nearly simultaneous observations of infrared SST and along-track altimetry is shown here through a case study in the Gulf Stream region. The presented approach relies on the characterization of a transfer function between the SST observations an...
Conference Paper
The growth of marine renewable energy and marine protected areas in France leads to a growing need for animal population knowledge at sea. Offshore energy generator projects (wind turbines for example) must obey these regulations and show their harmlessness to the environment, particularly to the wildlife and to protected species, which are vulnera...
Article
This paper studies the effects of stationary-based processing of moving ship signatures in synthetic aperture radar (SAR) imagery and introduces a methodology to estimate and compensate for them. SAR imaging of moving targets usually results in residual chirps in the azimuthal SLC processed signal. The fractional Fourier transform (FrFT) makes it p...
Conference Paper
The growth of marine renewable energy and marine protected areas in France leads to an increased need for animal population knowledge at sea. Offshore energy generator projects(wind turbines for example) must obey these regulations and show their harmlessness to the environment, particularly to the wildlife and to protected species, which are vulne...
Conference Paper
In this paper, we propose a test of hypothesis improvement, by phase study of the analytical cross-correlation function in acoustical detection application. Robustness of false alarms probability for the Time Of Arrival (TOA) estimation represents the goal of the proposed method. After signal detection, TOA will be used to localize one receiver, th...
Conference Paper
Full-text available
The NeXOS project aims to develop new multifunctional sensor systems supporting a number of scientific, technical and societal objectives, ranging from more precise monitoring and modelling of the marine environment to an improved management of fisheries. Several sensors will be developed, based on optical and passive acoustics technologies, addres...
Conference Paper
In this paper paper we address performances of ship detection algorithms in medium resolution SAR imagery. An automatic validation approach based on coastal AIS data allows to evaluate detectors efficiency. Detection capabilities remain sensitive to dataset features such as SAR imaging characteristics, meteorological conditions or vessel size. The...
Article
Our application concerns a system immersed in an underwater acoustical context, with Nt transmitters and Nr slowly moving receivers. The objective is that all receivers detect the transmitted signals, in order to estimate the time of arrival (TOA) and then to facilitate the localization when several TOA (more than 3) are present. We have to choose...
Conference Paper
Full-text available
In this work, we present a statistical model to generate relevant reanalysis of geophysical parameters. In particular, we use a stochastic equation to control the temporal and spatial variability of the signal and we take into account the possible error of the observations. We resolve the system iteratively using an ensemble Kalman filter and smoot...
Conference Paper
Full-text available
Development of a new generation of multifunctional sensor systems is underway to address ocean monitoring challenges. These range from more precise monitoring of the marine environment to an improved management of fisheries and, among other things, address improved life cycle cost-efficiency. These advances will be achieved through innovations such...
Article
This paper studies the performances of different ship detectors based on adaptive threshold algorithms. The detection algorithms are based on various clutter distributions and assessed automatically with a systematic methodology. Evaluation using large datasets of medium resolution SAR images and AIS (automatic identification system) data as ground...
Article
The observation of the ocean surface using electromagnetic sources of opportunity (GPS signals for instance) has been research topic for several years. Due to technological progress in space studies, we have seen an increase of deployment of GPS in several oceanographic applications such as remote sensing, kinematic measurements, ocean surface moni...
Conference Paper
Full-text available
Multi-satellite measurements of altimeter-derived Sea Surface Height (SSH) and Sea Surface Temperature (SST) provide a wealth of information about ocean circulation, espe-cially mesoscale ocean dynamics which may involve strong spatio-temporal relationships between SSH and SST fields. Within an observation-driven framework, we investigate the exten...
Article
IntroductionTFR application to sampled imagesMinimum properties and constraints on the kernelNotion of analytic imagesSpectral analysis application of SAR imagesApproximation of an internal wave trainBibliography
Book
For a long time, the signal processing (SP) community has limited itself to the field of 1-D signals, very often considering them to be an electronic quantity evolving over time. This approach was fundamentally associated with the type of acquisition which very often converted it in such a way as to display it on the screen of an oscilloscope and p...
Article
The latest generation of bathymetric multibeam echo sounders (MBES) uses frequency modulated (FM) signals with matched filtering using pulse compression in order to reach wider swath (by increasing the transmitted energy via pulse duration, resulting in a better SNR) while keeping a high accuracy (shorter efficient pulse duration). Practically, thi...
Conference Paper
For modern multibeam echosounders, the use of a robust and reliable quality estimator associated with each sounding is an absolute necessity. Indeed, due to the large volume of data acquired, a lot of time is lost, both during the survey and the post-processing. This is a costly problem for hydrographers. The definition of a quality estimator based...
Conference Paper
So far, sea surface scattering polarization sensitivity is still difficult to fully understand. To gain understanding, full polarization C-band data spectral analysis is considered and the de-polarization (HV) and polarization ratio (PR) are jointly analysed with in-situ wind and wave observations.
Conference Paper
This paper addresses the use of Global Navigation Satellite Systems (GNSS) as a remote sensing tool for oceanographic applications. In this paper we use the Global Positioning System (GPS) signals reflected off the sea surface along with a coastal receiver to perform detection and tracking of a near sea surface mobile target. Because these signals...
Conference Paper
The latest generation of bathymetric multibeam echo sounders uses FM modulated signal with pulse compression in order to explore deeper seafloor while keeping a high resolution. Practically, the expected performances are not reached, and the first explanation made is this is due to the Doppler from the antenna motion which affects the FM signals pr...
Conference Paper
This paper describes a methodology to model and simulate the reflectivity measured by radar observing a maritime environment. The simulation principle consists of reproducing the acquisition of a Real Aperture Radar (RAR) moving along its axis. Pulse after pulse, high range resolution profiles are successively computed by summing the contribution o...
Conference Paper
Full-text available
The observation of the ocean surface using electromagnetic sources of opportunity (GNSS signals for instance) has been a green research topic for several years. The Global Navigation Satellite System (GNSS) presents a powerful and useful technology for remote sensing, ocean surface monitoring and oceanography. Many experiments have been conducted t...
Conference Paper
Full-text available
The paper will describe the status of a work currently in progress under DGA/MRIS foundings, involving Alyotech Technologies, IFREMER Brest and Telecom Bretagne: the development of a new fast radar sea clutter simulator, running on GPU (Graphical Processing Units). Most radar sea clutter models provide statistical descriptions of backscattered sign...
Conference Paper
Signal processing is quite intensive when dealing with radar sensors. In this paper, the ability of spaceborne radars for imaging ocean surface features is explained and some of the very actual results are shown through several illustrations. The aim of such means to watch the earth is to provide useful information on a global basis regardless of t...
Chapter
Introduction to speckle Complex circular Gaussian model of single-look and scalar speckle Complex circular multi-variate Gaussian model of vectorial or multi-look speckle Non-Gaussian speckle models Polarimetric radar speckle
Chapter
Introduction to radar oceanography Sea surface description Image of a sea surface by a real aperture radar Sea surface motions SAR image of the sea surface Inversion of the SAR imaging mechanism
Conference Paper
Full-text available
A method for modeling and tracking convective clouds within radar images is presented. An object modeling approach is used, based on the extraction of grayscale skeletons from 2-dimensionnal cross-section of 3-dimensional radar data. Grayscale skeletons are appropriate shape descriptors for nonrigid and heterogeneous objects, in which gray-level lo...
Conference Paper
We propose the simulated rendition of the observation of a variety of small sea patches by radar. These patches include a random sea surface of variable state, with possibly the presence of a manufactured, metallic object in its middle. The simulation in itself draws upon two different techniques which are combined: for the free-space propagation,...
Article
This paper describes the setting of the experiment for in situ measurements of breaking waves. The aim is to provide an insight in the wave breaking mechanism and the possible outcome is a statistical description of this mechanism which will be used together with airborne radar (SAR) data acquired on the same spot. It is well known that when the se...
Conference Paper
This paper describes the goals of the MODENA project, aiming at a fine description of the maritime environment by means of electromagnetic sensors. The main steps of the project go through a modeling of the ocean surface, the man-made objects on the surface as well as of the interaction between the electromagnetic waves with this surface and the ob...
Conference Paper
Challenges facing ocean remote sensing are as unlimited as the variety of sea surface dynamics and meteorological conditions across the globe and their range of spatial and time scales. Ultimate goals are to be able to make accurate estimates of selected key sets of geophysical variables, with the intention of either making predictions across time...
Article
The performance and operational feasibility of the high-frequency Wellen Radar Doppler radar have been demonstrated in a region dominated by strong tidal currents during the SURveillance LITtorale OPerationnelle experiment in Brittany (France). Local weather-oceanic phenomena (current-wave-wind interactions) were measured for the first time by temp...
Book
This chapter details the basics of radar backscattering over a rough surface (such as the sea) as well as the sea surface mapping by a synthetic aperture radar. Nonlinear phenomena involved in the sea SAR mapping, from the intrumental as well as hydrodynamic points of view, are detailled. Finaly, the presentation reminds the usual techniques to inv...
Article
In this chapter, we tackled higher order statistics (HOS) for 2-D signals. In the first part, we recall the definitions of moments and spectra of higher orders as well as their generalization to 2-D signals. We see that the third-order moments as well as the bispectra are 4-D quantities and that the exploitation of the information contained in this...
Conference Paper
A simulation of the synthetic aperture radar (SAR) observation of a complex sea scene is proposed. The observed sea patch consists of sea clutter and a metallic, steady object. The simulation process is based on a local, discrete calculation using the finite difference method in the time domain. This approach turns out to be relevant when consideri...
Conference Paper
In SAR image processing, taking phase distortion in radar signals into account is equivalent to considering motion as information embedded in it. In the aim of doing this, a model based on Gaussian linear frequency modulation is introduced, adapted to quantification and estimation of phase distortion. This model is based on three parameters, the Do...
Conference Paper
Simulating realistic sonar data is crucial for tuning detection and classification algorithms according to environment and acquisition characteristics. Moreover, robustness of performances estimation and prediction applications can be greatly enhanced as soon as such a simulation tool provides both a modular underwater world representation (multipl...
Article
In this paper, we consider the surface motion as an important factor governing behaviours of the sea clutter observed in SAR images. Therefore, we propose a model for SAR - acquisition of time varying scenes. Then we derive from this model the 2nd order statistical properties of an acquired scene in terms of a time - dependant reflectivity q. We al...
Article
Performance and operational feasibility of very high-frequency (VHF) Doppler radar have been demonstrated in a region dominated by strong tidal currents. An analysis of remote measurements of sea surface currents acquired by Courants de Surface MEsureacutes par Radar (COSMER)-pulsed Doppler radar during Evaluation et Preacutevision de l'Environneme...
Conference Paper
Full-text available
The Global Earth Observation System of Systems (GEOSS) is foreseen to be a complex system of sensors, models, communication devices, storage systems, computational and other hardware elements used in concert to "to improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behavior of the...
Article
This paper concerns the possibilities for side scan sonar to determine the bathymetry. High definition sea-bottom imaging is the primary task for new side scan sonars; nevertheless, these systems are also able to estimate the relief with a definition equal to the pixel resolution of conventional imaging sonar, through an interferometric multisensor...
Conference Paper
Maritime transport and traffic is following the growing slope of trade exchanges between continents and nations. Maritime risks and economic constraints increase at the same speed, together with international competition. This context may be the best asset to join private interests of companies with general concerns of maritime regions for safer se...
Article
Full-text available
Galileo is one of the most important research program launched jointly by the European Commission, the European Space Agency and managed with the industry through the Galileo consortium. Galileo is a constellation of 33 satellites that will complete the fleet of 28 satellites of the American GPS and 24 satellites of GLONASS, the whole promising vis...
Article
This paper is an attempt to compare two interferometric processings. The first one is applied to traditional space-borne radar (SAR) and the second on recent interferometric sonar data. Few comparisons between those techniques have already been made, despite the fact that they share many similar principles, only a. Thus, the key idea of this articl...
Article
From the recent availability of images recorded by synthetic aperture radar (SAR) airborne systems, automatic results of digital elevation models (DEMs) on urban structures have been published lately. This paper deals with automatic extraction of three-dimensional (3-D) buildings from stereoscopic high-resolution images recorded by the SAR airborne...
Conference Paper
The present work develops a new aspect in the use of HF radar as a tool for real time operational oceanography. We propose to implement new algorithms for detecting anomalies (outliers) on VHF radar data. Perspectives of such work are to detect changes in sea surface, such as ship or oil pollution. In this preliminary work, no information are given...