Monitoring post-fire forest recovery using multi-temporal Digital Surface Models generated from different platforms

Wildfires can greatly affect forest dynamics. Given the alteration of fire regimes foreseen globally due to climate and land use changes, greater attention should be devoted to prevention and restoration activities. Concerning in particular post-fire restoration actions, it is fundamental, together with a better understanding of ecological processes resulting from the disturbance, to define techniques and protocols for long-term monitoring of burned areas. This paper presents the results of a study conducted within an area affected by a stand-replacing crown fire (Verrayes, Aosta (AO), Italy) in 2005, which is part of a long-term monitoring research on post-fire restoration dynamics. We performed a change detection analysis through a time sequence (2008-2015) of DSMs (Digital Surface Models) obtained from LiDAR (ALS - Airborne Laser Scanner) and digital images (UAV - Unmanned Aerial Vehicle flight) to test the ability of the systems (platform + sensor) to identify the ongoing processes. New technologies providing high-resolution information and new devices (i.e. UAV) able to acquire geographic data “on demand” demonstrated great potential for monitoring post disturbance recovery dynamics of vegetation

Cartographic data harmonisation for a cross-border project development

An essential support for environmental monitoring activities is a rigorous definition of an homogeneous cartographic system required to correctly georeference the acquired data. Furthermore, since the 2007, the European INSPIRE Directive (INfrastructure for Spatial InfoRmation in the European Community) affirms the necessity to harmonize the European maps for permitting cross-border analysis. For satisfying these requirements, the authors have developed a procedure for the cartographic harmonisation in the cross border area studied during in the European project ALCOTRA (Alpes Latines- COopération TRAnsfrontalière) – ALIRHyS (Alpes Latines- Individuation Resources Hydriques Souterraines). It concerns the hydrogeological study of various springs and other water resources in an area between Italy and France including their constitution in a cross-border system. The basic cartographic information is obtained from existing national maps (Italian and French data), which use different reference systems and are produced from different data acquisitions and processes. In this paper the authors describe the methods used to obtain well-harmonised middle-scale maps (aerial orthophotos, Digital Terrain Model and digital maps). The processing has been performed using GIS software or image analysis software in order to obtain useful and correct cartographic support for the monitoring data, even if the obtained maps could be further analysed or refined in future works

URBAN DATA COLLECTION USING A BIKE MOBILE SYSTEM WITH A FOSS ARCHITECTURE

European community is working to improve the quality of the life in each European country, in particular to increase the quality air condition and safety in each city. The quality air is daily monitored, using several ground station, which do not consider the variation of the quality during the day, evaluating only the average level. In this case, it could be interesting to have a “smart” system to acquire distributed data in continuous, even involving the citizens. On the other hand, to improve the safety level in urban area along cycle lane, road and pedestrian path, exist a lot of algorithms for visibility and safety analysis; the crucial aspect is the 3D model considered as “input” in these algorithms, which always needs to be updated. A bike has been instrumented with two digital camera as Raspberry PI-cam. Image acquisition has been realized with a dedicated python tool, which has been implemented in the Raspberry PI system. Images have been georeferenced using a u-blox 8T, connected to Raspberry system. GNSS data has been acquired using a specific tool developed in Python, which was based on RTKLIB library. Time synchronization has been obtained with GNSS receiver. Additionally, a portable laser scanner, an air quality system and a small Inertial platform have been installed and connected with the Raspberry system. The system has been implemented and tested to acquire data (image and air quality parameter) in a district in Turin. Also a 3D model of the investigated site has been carried. In this contribute, the assembling of the system is described, in particular the dataset acquired and the results carried out will be described. different low cost sensors, in particular digital camera and laser scanner to collect easily geospatial data in urban area

Precision Agriculture Workflow, from Data Collection to Data Management Using FOSS Tools: An Application in Northern Italy Vineyard

In the past decades, technology-based agriculture, also known as Precision Agriculture (PA) or smart farming, has grown, developing new technologies and innovative tools to manage data for the whole agricultural processes. In this framework, geographic information, and spatial data and tools such as UAVs (Unmanned Aerial Vehicles) and multispectral optical sensors play a crucial role in the geomatics as support techniques. PA needs software to store and process spatial data and the Free and Open Software System (FOSS) community kept pace with PA’s needs: several FOSS software tools have been developed for data gathering, analysis, and restitution. The adoption of FOSS solutions, WebGIS platforms, open databases, and spatial data infrastructure to process and store spatial and nonspatial acquired data helps to share information among different actors with user-friendly solutions. Nevertheless, a comprehensive open-source platform that, besides processing UAV data, allows directly storing, visualising, sharing, and querying the final results and the related information does not exist. Indeed, today, the PA’s data elaboration and management with a FOSS approach still require several different software tools. Moreover, although some commercial solutions presented platforms to support management in PA activities, none of these present a complete workflow including data from acquisition phase to processed and stored information. In this scenario, the paper aims to provide UAV and PA users with a FOSS-replicable methodology that can fit farming activities’ operational and management needs. Therefore, this work focuses on developing a totally FOSS workflow to visualise, process, analyse, and manage PA data. In detail, a multidisciplinary approach is adopted for creating an operative web-sharing tool able to manage Very High Resolution (VHR) agricultural multispectral-derived information gathered by UAV systems. A vineyard in Northern Italy is used as an example to show the workflow of data generation and the data structure of the web tool. A UAV survey was carried out using a six-band multispectral camera and the data were elaborated through the Structure from Motion (SfM) technique, resulting in 3 cm resolution orthophoto. A supervised classifier identified the phenological stage of under-row weeds and the rows with a 95% overall accuracy. Then, a set of GIS-developed algorithms allowed Individual Tree Detection (ITD) and spectral indices for monitoring the plant-based phytosanitary conditions. A spatial data structure was implemented to gather the data at canopy scale. The last step of the workflow concerned publishing data in an interactive 3D webGIS, allowing users to update the spatial database. The webGIS can be operated from web browsers and desktop GIS. The final result is a shared open platform obtained with nonproprietary software that can store data of different sources and scales

Spectral Evidence of Ice on Aircrafts – The SEI Project

The general objective of the SEI project (reference call: MANUNET III 2018) is to experiment spectral sensor fusion techniques of data acquired by UAVs (Unmanned Aerial Vehicles) during aircraft preflight inspection. In General Aviation, an important safety issue regards the presence of ice on the aircraft's fuselage and wings. Ice on the wings can cause loss of lift and stalling, which in most cases would result, during take-off phase, in airplane’s fatal crash. Another important aspect to consider is the high amount of de-icing liquid usually involved in the process incurring in high costs and considerable damage to the environment. This is not a typical industrial scenario, but the project addresses important aspects related to the manufacturing sector: it has to accomplish specific tasks following a design process; it involves human operators (labour) collaborating with machines and tools; it includes the usage of semi-raw materials (glycol fluids) to accomplish a service; it sees serialization of the process that could be invoked at any needed time. Moreover, it targets safety issues both for operators and machines regarding reliability of results at the end of the process, it is order-based and comparable to a discrete manufacturing process

UAV data acquisition and analysis for a Cultural Landscape Heritage: the emergency area of the Vallone d’Elva.

In the last decades, the technology progress in the cultural and environmental field has had a loud growth. The authors applied drone and terrestrial photogrammetric techniques for a complete survey on a complex Cultural Landscape Heritage, requiring protection and promoting actions. These technologies were used to obtain even more detailed 3D point clouds, terrain models, orthophotos (also new quasi-vertical product) with a centimetre accuracy, for tourism development and landslide hazard prevention on road and villages, also reducing survey costs in a complex and limited orography site

UAV per la generazione di DSM multi-temporali per il monitoraggio delle dinamiche di ricostituzione post-incendio di aree boschive

Gli incendi boschivi sono uno dei principali disturbi naturali che influenzano le dinamiche degli ecosistemi forestali. Gli effetti degli incendi boschivi possono variare a seconda dell'intensità dell'evento, fino a raggiungere severità tali da determinare la morte dell'intero soprassuolo forestale. L’alterazione del regime degli incendi boschivi prevista a livello globale in relazione ai cambiamenti climatici e di uso del suolo, comporta una sempre maggiore attenzione agli aspetti di prevenzione e ricostituzione delle aree interessate. Nell’ambito, in particolare, della ricostituzione post-incendio, appare fondamentale, oltre all’approfondimento delle conoscenze sui processi ecologici in risposta al disturbo, definire tecniche e protocolli di monitoraggio di lungo periodo. In questo contesto, l’utilizzo di Unmanned Aerial Vehicle (UAV) può essere uno strumento utile allo svolgimento di indagini a media scala in aree interessate da incendi boschivi. Infatti questi strumenti, che offrono la possibilità di installare a bordo sensori di natura diversa, quali camere multispettrali o sensori termici, consentono di effettuare rilievi speditivi e ripetibili nel tempo, fondamentali per analisi multi-temporali delle aree di interesse. In questo articolo vengono presentati i risultati preliminari relativi ad un’indagine condotta all’interno di un’area interessata nel 2005 da un incendio di chioma (Verrayes, AO) nell’ambito di un progetto di monitoraggio di lungo periodo delle dinamiche di ricostituzione post-incendio. E’ stato pertanto realizzato un rilievo speditivo con UAV con camere visibili e multispettrali al fine di generare un modello della superficie (Digital Surface Model – DSM) da confrontare con un precedente modello ottenuto tramite rilievo lidar

Rilievo metrico 3D multiscala per l’indagine e la rappresentazione architettonica e ambientale dell’area archeologica di Susa

L’articolo presenta alcuni dei risultati raggiunti in seguito ad uno degli stages didattici proposti dagli autori agli studenti dei corsi di laurea delle aree di Architettura e di Ingegneria del Politecnico di Torino inerente il rilievo metrico 3D che si è svolto a fine 2013 nell’area archeologica di Susa. L’attività è stata sostenuta dall’Ateneo, con i fondi del 5 per mille, e da alcuni enti territoriali locali (Regione Piemonte, Città di Susa, associazioni culturali locali). Le attività di acquisizione hanno previsto l’integrazione di metodi multisensore e, in particolare, l’impiego di tecniche di fotogrammetria terrestre (close-range), RPAS (Remotely piloted aircraft system) e laser scanner. L’elaborazione dei dati acquisiti è consistita nella loro registrazione e georeferenziazione nel sistema di riferimento globale, utilizzando l’appoggio topografico legato ai vertici della rete misurati con tecniche GPS-GNSS, e nella costruzione di modelli di superficie continui. I modelli 3D ottenuti si caratterizzano per la diversa natura dei dati impiegati nella loro generazione e per il contenuto informativo multiscala: scansioni laser terrestri, modelli stereoscopici e ortofoto generati da voli a bassa quota tramite UAV dell’area archeologica, acquisizioni fotogrammetriche e laser scanning ad alta risoluzione di decorazioni architettoniche complesse e figurate quali il fregio dell’arco di Augusto di Susa ed infine dati estratti da voli utili per l’aggiornamento di cartografie tecniche regionali e provinciali. Tali modelli tridimensionali sono stati integrati al fine di ottenere una descrizione più completa degli oggetti indagati permettendo così l’elaborazione di molteplici rappresentazioni utili a diversi scopi: restituzione grafica (2D e 3D) dei singoli manufatti e dell’area, estrazione di ortofoto, indagine archeologica, ricostruzione archeologica delle architetture antiche etc. I risultati ottenuti alle diverse scale sono stati infine implementati all’interno di un GIS interrogabile in relazione a molteplici necessità, integrabile continuamente con informazioni aggiuntive provenienti dagli studi archeologici o territoriali e utilizzabile per la visualizzazione 3D tematizzata delle informazioni ottenute

The use of unmanned aerial vehicles (UAVs) for engineering geology applications

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Effect of the UAV orientation in antenna pattern measurements

A novel radiation pattern measurement system for VHF and UHF antennas has been recently developed using the Unmanned Aerial Vehicle (UAV) technology. This paper discusses the effect of the UAV orientation and the applicable corrections on the pattern extraction procedure, in order to increase the accuracy and repeatability of the measurements