The concept of REA (Rapid Environmental Assessment) outlines the ability of acquiring environmental information and, subsequently, processing and valorizing, in order to return a finished product in the shortest possible time. Hence, the focal point of a REA activity is expressed in the ability of immediately reacting to certain events, often basing the operations on very limited data, therefore gaining a strategic importance under the point of view of the result. The knowledge and the observation of natural phenomenon require a multidisciplinary approach based upon high-quality data, which have to be acquired with accuracy through standardized procedures. REA activities are applied to procedures that involve the rapid characterization of particular environments, like littoral area or deep sea, for research and rescue purposes, but also for interventions following natural calamities and activities of Civilian Protection. The purpose of the researches is to develop innovative tools for REA activities, studying the usage of acoustic sensors, particularly the MultiBeam Echo Sounder (MBES) and the derived mapping products, such as seabed morphology layer, acoustic backscatter layer and water column images, through a new usage and elaboration methodology of the backscatter data, in order to return an integrated seabed3D-mapping. Within the use of the Water Column Image, the process of data valorization which allows to explore the water column in its complexity and three-dimensionality has been studied more in depth. Furthermore, in the study of the acoustic backscatter, a process aimed at the automatic characterization and classification of the seabed, derived by an analysis of the backscatter’s data, was developed. This was possible by taking advantage of a multiparametric technique, used in the satellite image process, which supposes the contemporary usage of three parameters, that characterize the backscatter’s signal. Finally, as an additional tool for REA activities, the usage of remote sensing, with the elaboration of the information derived by multi-spectral satellites for the determination of the seabed character and bathymetry and of the orthophoto acquired by an aerial drone, was taken into consideration, in order to return the height and the depth of the emerged and submerged parts. The main point of the research was the extraction of the seabed’s classification data, starting from the backscatter’s data. The multiparametric analysis underlined its strong potentiality in the application of a REA activity, allowing to reach an automatic classification of the acoustic backscatter’s data up to 6 categories of seafloor classes, with its own mapping. This new tool allowed to characterize the seabed with MBES analysis in “near real time”, without having to use a calibration Ground Truth, except for the initialization phases. The concept of REA is extremely variegated and only an holistic and multidisciplinary approach can take into consideration the various characteristics. This research does not end with the development of a new evaluation method applied to seabed mapping, but it represents the starting point for further developments in the valorization of the acoustic MBES data, such as the backscatter and the automatic processing.
Il concetto di valutazione rapida ambientale (Rapid Environmental Assessment - REA) si estrinseca nella capacità di acquisire le informazioni dell’ambiente circostante, elaborarle, valorizzarle e restituire un prodotto finito, nel più breve tempo possibile. Il punto focale di una attività REA si esprime quindi in una capacità di reazione all’evento immediata su informazioni di base spesso limitate ma rivestendo un’importanza strategica dal punto di vista del risultato. La conoscenza e l’osservazione di fenomeni naturali necessitano quindi di un approccio multidisciplinare, richiedendo dati di alta qualità, acquisiti con accuratezza e secondo delle procedure standardizzate. Le attività REA si applicano ad azioni mirate alla caratterizzazione rapida di particolari ambiti come l’area costiera o il mare profondo, per scopi di ricerca e soccorso, ma anche per interventi a seguito di calamità naturali e attività di protezione civile. Questo lavoro di ricerca si rivolge allo sviluppo di tools innovativi per le attività REA, studiando l’impiego di sensori acustici, in particolare del MultiBeam Echo Sounder (MBES) e dei prodotti di mapping da esso derivati, Seabed morphology, acoustic Backscatter e Water Column Images, attraverso una nuova metodologia d’impiego e di elaborazione del dato di backscatter per restituire un modello integrato di 3Dmapping. Nell’utilizzo del Water Column Image, è stato approfondito il processo di valorizzazione del dato che ha permesso di esplorare la colonna d’acqua nella sua complessità e nella sua tridimensionalità. Nello studio del backscatter acustico, si è poi sviluppato un processo rivolto alla classificazione e caratterizzazione automatica del seabed derivato dalla analisi del dato di backscatter, sfruttando una tecnica multiparametrica, derivata dall’utilizzo su immagini satellitari, che prevede l’impiego in contemporanea di più parametri caratterizzanti il segnale di backscatter. Infine, quale ulteriore tool per le attività REA, è stato l’impiego del remote sensing con l’uso delle informazioni derivate da satelliti multispettrali per la determinazione delle caratteristiche del seabed e la determinazione del valore di profondità del fondale e delle ortofoto acquisite da drone aereo per la restituzione della parte emersa e sommersa in termini di elevazione e profondità. L’estrazione del dato di classificazione del seabed dal dato di backscatter ha rappresentato il punto focale della ricerca. L’analisi multiparametrica ha evidenziato le sue forti potenzialità nell'applicazione di un REA permettendo di arrivare ad una classificazione automatica del dato acustico di backscatter fino a 6 classi della natura del fondo con il relativo mapping. Questo nuovo strumentoha permesso di caratterizzare il seabed con rilievi MBES in “near real time”, senza dover ricorrere a Ground Truth di calibrazione, fatta eccezione della fase di inizializzazione. Il concetto di REA è infatti un concetto estremamente vario e solamente un approccio olistico, multidisciplinare può considerare le varie sfaccettature. Questa ricerca non si conclude con lo sviluppo di un nuovo metodo di valutazione applicato al seabed mapping, ma rappresenta la base di partenza per ulteriori sviluppi della valorizzazione dei dati acustici MBES quali il Backscatter e il processing automatico.
Innovative REA tools for seabed mapping
-
2020
Abstract
The concept of REA (Rapid Environmental Assessment) outlines the ability of acquiring environmental information and, subsequently, processing and valorizing, in order to return a finished product in the shortest possible time. Hence, the focal point of a REA activity is expressed in the ability of immediately reacting to certain events, often basing the operations on very limited data, therefore gaining a strategic importance under the point of view of the result. The knowledge and the observation of natural phenomenon require a multidisciplinary approach based upon high-quality data, which have to be acquired with accuracy through standardized procedures. REA activities are applied to procedures that involve the rapid characterization of particular environments, like littoral area or deep sea, for research and rescue purposes, but also for interventions following natural calamities and activities of Civilian Protection. The purpose of the researches is to develop innovative tools for REA activities, studying the usage of acoustic sensors, particularly the MultiBeam Echo Sounder (MBES) and the derived mapping products, such as seabed morphology layer, acoustic backscatter layer and water column images, through a new usage and elaboration methodology of the backscatter data, in order to return an integrated seabed3D-mapping. Within the use of the Water Column Image, the process of data valorization which allows to explore the water column in its complexity and three-dimensionality has been studied more in depth. Furthermore, in the study of the acoustic backscatter, a process aimed at the automatic characterization and classification of the seabed, derived by an analysis of the backscatter’s data, was developed. This was possible by taking advantage of a multiparametric technique, used in the satellite image process, which supposes the contemporary usage of three parameters, that characterize the backscatter’s signal. Finally, as an additional tool for REA activities, the usage of remote sensing, with the elaboration of the information derived by multi-spectral satellites for the determination of the seabed character and bathymetry and of the orthophoto acquired by an aerial drone, was taken into consideration, in order to return the height and the depth of the emerged and submerged parts. The main point of the research was the extraction of the seabed’s classification data, starting from the backscatter’s data. The multiparametric analysis underlined its strong potentiality in the application of a REA activity, allowing to reach an automatic classification of the acoustic backscatter’s data up to 6 categories of seafloor classes, with its own mapping. This new tool allowed to characterize the seabed with MBES analysis in “near real time”, without having to use a calibration Ground Truth, except for the initialization phases. The concept of REA is extremely variegated and only an holistic and multidisciplinary approach can take into consideration the various characteristics. This research does not end with the development of a new evaluation method applied to seabed mapping, but it represents the starting point for further developments in the valorization of the acoustic MBES data, such as the backscatter and the automatic processing.| File | Dimensione | Formato | |
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