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

A low cost mobile mapping system (LCMMS) for field data acquisition: a potential use to validate aerial/satellite building damage assessment

Among the major natural disasters that occurred in 2010, the Haiti earthquake was a real turning point concerning the availability, dissemination and licensing of a huge quantity of geospatial data. In a few days several map products based on the analysis of remotely sensed data-sets were delivered to users. This demonstrated the need for reliable methods to validate the increasing variety of open source data and remote sensing-derived products for crisis management, with the aim to correctly spatially reference and interconnect these data with other global digital archives. As far as building damage assessment is concerned, the need for accurate field data to overcome the limitations of both vertical and oblique view satellite and aerial images was evident. To cope with the aforementioned need, a newly developed Low-Cost Mobile Mapping System (LCMMS) was deployed in Port-au-Prince (Haiti) and tested during a five-day survey in FebruaryMarch 2010. The system allows for acquisition of movies and single georeferenced frames by means of a transportable device easily installable (or adaptable) to every type of vehicle. It is composed of four webcams with a total field of view of about 180 degrees and one Global Positioning System (GPS) receiver, with the main aim to rapidly cover large areas for effective usage in emergency situations. The main technical features of the LCMMS, the operational use in the field (and related issues) and a potential approach to be adopted for the validation of satellite/aerial building damage assessments are thoroughly described in the articl

DIRECT PHOTOGRAMMETRY USING UAV: TESTS AND FIRST RESULTS

In recent years, the quality of high resolution acquisition platforms for geomatic applications has decidedly increased, especially in the performance of the sensors devoted to image acquisition.<br><br> The small size of these new sensors combined with the increase in resolution allows them to be easily mounted onto Unmanned Aerial Vehicles (UAVs); in particular, calibrated, very-high-resolution digital cameras for photogrammetric purposes such as digital terrain model (DTM) and digital surface model (DSM) extraction, orthophotos, and map realization have been used. In this case, the UAV performance allows a high quality product to be obtained, considering the pixel size and the accuracy of the DTM/DSM which could be obtained with automatic procedures.<br><br> Several navigation sensors (GPS/GNSS and IMU-MEMS) are embedded into UAVs in order to realize autonomous flight. The quality of these sensors, in terms of accuracy, depends on the model of UAV and its purpose. The navigation solution (position and attitude) is estimated by the internal UAV sensor and can be employed to directly georeference the images, in order to produce an quick and easy description and analysis of the overlooked area. This is a good condition for semi-automatic procedures using a bundle-block photogrammetric approach. But is it possible to realize a direct photogrammetry? And what are the limits?<br><br> Several tests were carried out over different areas and in different conditions using three different UAVs belonging to the Geomatics group of the Politecnico di Torino.<br><br> In this paper, an investigation of the limits of some commercial UAVs is reported, defining a dedicated procedure to valuate their performance, especially considering the use of UAVs for direct photogrammetry

Using compact GML to deploy interactive maps on mobile devices

As users get connected with new-generation smart programmable phones and Personal Digital Assistants, they look for geographic information and location-aware services. In such a scenario, developers need infrastructures and standards in order to provide geographic data and cartographic tools to a wide set of applications and small mobile devices. GIS market offers a rich set of powerful tools for geographic information management, but a simple and lightweight protocol to easily add cartographic functionalities to mobile applications is still missing. This paper presents the compact Geographic Markup Language (cGML), a custom version of GML tailored for mobile devices. By using small tags, server side pre-projected and pre-scaled coordinates, it allows development and deployment of map-based software for mobile phones and PDAs with strong constraints on connection, CPU and memory

Itv as a community-to-community collaborative system

Web-forums and Instant Messengers provide a unique opportunity for the users to create and support spontaneous communities. However, such systems tend to focus on the one-to-one and one-to-many approaches. Community-to- Community interaction, described as two groups of people which communicate by means of a network, is still missing. This work describes early implementation of an interactive television (iTV) chat system, which dynamically creates chat rooms where users can discuss, share their TV experience and access web resources.337-33

Building the Web of Things with WS-BPEL and Visual Tags. Web of Things using Service-oriented Architecture standards

The Web of things is an emerging scenario in which everyday objects are connected to the Internet and can answer to HTTP queries with structured data. This paper presents a system that allows users to build networks of everyday objects using visual tags as proximity technology. The system backend is based on Service-oriented Architecture languages and tools for the runtime composition of “things” establishing connections we call hyperpipes.357-36

Il cgml: una soluzione basata su xml per la rappresentazione di mappe vettoriali su dispositivi mobili

L’evoluzione tecnologica dei dispositivi mobili, in termini di potenza di calcolo, capacità di visualizzazione e memorizzazione, e il proliferare di sistemi di connessione a banda larga su rete locale wireless (WiFi) e cellulare (UMTS), permette la gestione di dati complessi quali le mappe vettoriali e l’accesso ai Location Based Service (LBS) per mezzo di un telefono cellulare o un palmare. L’uso di linguaggi XML nel settore dei LBS condiziona la struttura delle funzionalità e dei dati ma garantisce l’interoperabilità dei servizi. Un esempio è il linguaggio GML (Geographic Markup Language) standard de facto nello scambio dei dati tra sistemi GIS e nella rappresentazione dell’informazione geografica. Il GML non è orientato alla rappresentazione di mappe vettoriali, è quindi necessario trasformarlo in un altro linguaggio XML, ad esempio il linguaggio grafico SVG (Scalable Vector Graphics). Per evitare la separazione tra il dato geografico (GML) e la sua visualizzazione (Mobile SVG) ma usando comunque le mappe vettoriali su dispositivi mobili, abbiamo definito il cGML (compact Geographic Markup Language). La rappresentazione di un dato tramite cGML è una mappa vettoriale e come tale può essere utilizzata nella presentazione grafica, ma allo stesso momento è anche un contenitore di insiemi di dati geo-riferiti, omogenei per semantica, utilizzabili in elaborazioni locali sul dispositivo mobile.Enhanced mobile device performances, in terms of CPU power, memory capacity, display capabilities and adoption of wideband connectivity based on local wireless (WiFi) and cellular (UMTS) networks, bring interactive mapping and access to Location Based Services (LBS) to mobile phones and PDAs. The use of XML language in the LBS influences data structure, functionalities and performances; although it could be time and memory expensive, it guarantees service interoperability. The GML language (Geographic Markup Language) is "de facto" standard in data exchanging between Geographic Information Systems. The GML has not been designed to represent vector map: it has to be transformed into another XML language, for example the graphical-oriented XML language Mobile SVG. To avoid the separation between the geographic data (GML) and its visualization (Mobile SVG), keeping vector mapping on mobile devices, we have designed the cGML (compact Geographic Markup Language). The data encoded using cGML is a vector map, so that it can be used in the graphic representation, but at the same time it is a container of geographical related data set, homogenous for semantic and usable in local processing on the mobile device

Compact gml: merging mobile computing and mobile cartography

The use of portable devices is moving from "Wireless Applications", typically implemented as browsing-on-the-road, to "Mobile Computing", which aims to exploit increasing processing power of consumer devices. As users get connected with smartphones and PDAs, they look for geographic information and location-aware services. While browser-based approaches have been explored (using static images or graphics formats such as Mobile SVG), a data model tailored for local computation on mobile devices is still missing. This paper presents the Compact Geographic Markup Language (cGML) that enables design and development of specific purpose GIS applications for portable consumer devices where a cGML document can be used as a spatial query result as well

Lightweight client-pull protocol for mobile communication

Consumer mobile devices, such as cellular phones and PDAs, rely on TCP/IP as main communication protocol. However, cellular networks are not reliable as wired and wireless LAN, due to both users mobility and geographical obstacles. Moreover, limited bandwidth outside urban areas requires an application level data priority management, in order to improve user experience and avoid communication stack deadlocks. This paper presents early specification and first prototype of the LCPP (Lightweight Client-Pull Protocol), a UDP-based communication protocol specially designed to provide better performance, fast responsiveness and save processing power on mobile devices. Using some concepts adopted in the field of P2P file sharing, LCPP provides data priority management approach, which enables application to negotiate concurrent access to communication channel and to be notified about delaying, network congestion or remote device inability to process data

The cgml: a xml language for mobile cartography

Increasing processing power and storage capabilities encourage systematic adoption of high-end mobile devices, such as programmable cellular phones and wireless-enabled PDA to implement new exciting applications. The performances of modern mobile devices are bringing innovative scenarios, based on position awareness and ambient intelligence paradigms. The market is moving from old 'Wireless Applications' approach to Mobile Computing, which aims to exploit mobile host capabilities. This paper presents the compact Geographic Markup Language (cGML), an XML-based language defined to enable design and development of LBS applications specific for mobile devices, and an example of client-server architecture using it