2nd edition of instrumenting smart city applications with big sensing and earth observatory data: Tools, methods and techniques

In lieu of an abstract, this is an excerpt from the first page. The exponential growth in the volume of Earth observation data and the increasing quality and availability of high-resolution imagery are increasingly making more applications possible in urban environments. In particular, remote sensing information, especially when combined with location-specific data collected locally or through connected devices, presents exciting opportunities for smart city applications, such as risk analysis and mitigation, climate prediction, and remote surveillance. On the other hand, the exploitation of this great amount of data poses new challenges for big data analysis models and requires new spatial information frameworks capable of integrating imagery, sensor observations, and social media in geographic information systems (GIS)

A combined change detection procedure to study desertification using opensource tools

Abstract Background and Methods The paper presents a combination of two unsupervised techniques for change detection studies in arid and semi-arid areas. Among Remote Sensing change detection techniques, unsupervised approaches have the advantage of promptly producing a map of the change between two dates, but often the interpretation of the results is not straightforward, and requires further processing of the image. The aim of the research is to propose a new time effective and semi-automated reproducible technique in order to reduce the weakness of the unsupervised approach in change detection. Two techniques, Change Vector Analysis (CVA) and Maximum Autocorrelation Factor transform of Multivariate Alteration Detector components (MAD/MAF) are chosen to serve the purpose. Results and Conclusions The results of the research, applied to two case studies in the Middle East region, indicate that the chosen techniques complement each other, since MAD/MAF gives a detailed spatial extent while CVA gives the semantic interpretation of the output. The research brings further understanding to the use of both unsupervised procedures and the methodology can be used as a fast semi-automatic preliminary step for more accurate change detection studies. A further output is a new add-on implementing CVA for the GFOSS (Geospatial Free and Open Source Software) project Grass GIS

Mobile data acquisition and processing in support of an urban heat island study

Global warming and changes in Earth’s weather patterns are the main consequences of climate change, and bioclimate discomfort has significant public health problems, especially for the elderly. Normally, the thermal characteristics of urban areas are poor due to a phenomenon known as urban heat island. Mobile and fixed temperature measurements were performed on 19 March 2021 in the city of Bologna, Italy. Mobile measurements took place with a car, along a 75-km transect, starting at 22:16 with a duration of 2 hours and 41 minutes, while fixed measurements were done using 15 present weather stations and also placing five thermometers in the city center. Various interpolation models (i.e., Traditional, Voronoi Tessellation, Global Trends, Triangulated Irregular Networks, Inverse Distance Weighting and Kriging) were applied to correct the mobile measurements using fixed data. Kriging fulfilled the best result with a correlation coefficient of 0.99 compared to the raw temperatures

MONITORING THE URBAN GROWTH OF DHAKA (BANGLADESH) BY SATELLITE IMAGERY IN FLOODING RISK MANAGEMENT PERSPECTIVE

There is large consensus that demographic changes, the lack of appropriate environmental policies and sprawling urbanization result in high vulnerability and exposure to the natural disasters. This work reports some experiences of using multispectral satellite imagery to produce landuse/cover maps for the Dhaka city, the capital of Bangladesh, which is subject to frequent flooding events.The activity was conducted in collaboration with the non-profit organization ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The Landsat images acquired in 2000, 2002 and 2009 were used to evaluate the urban growth in order to support risk assessment studies; to identify areas routinely flooded during the monsoon season, the image of October 2009 (the most critical month for the effects of rain) was compared with two images acquired in January and February 2010. The analysis between 2000 and 2009 was able to quantify a very rapid growth of the metropolis, with an increase in built-up areas from 75 to 111 km2. The analysis highlights also a sharp rise of Bare soil class, likely related to the construction of embankments for the creation of new building space; consequently a decrease of cultivated land was observed. In particular, these artificial islands have been invading flooding areas. The change detection procedure also showed that the flooding in October 2009 affected about 20% (115 out of 591 km2) of the entire study area; furthermore these areas became wetlands and farmland over the next three/four months

3D Survey and Data Processing of Bolivian Archaeology: The Ritual Receptacle from Tiwanaku

The archaeological site of Tiwanaku is among the most important examples of Bolivian archaeology and UNESCO World Heritage Site since 2000. This works reports a geomatic-based surveying and modelling methodology applied to a ritual receptacle excavated from the semi-subterranean temple in the archaeological complex. A high-resolution 3D survey was conducted through structured-light projection scanning and post-processing operations were carried out to emphasize surface details. Most of the operations were conducted in open-source software, with the aim to establish a quick and repeatable methodology to be applied to similar case studies. The final outputs, consisting of geometry projections (unrolled meshes), digitally enhanced surfaces and vector graphics can support the work of archaeologists in interpreting the iconography depicted on the receptacle and to conduct further studies to shed light about culture and religion of the civilization that inhabited Tiwanaku

High-Resolution 3D Survey and Visualization of Mesopotamian Artefacts Bearing Cuneiform Inscriptions

This paper presents some considerations and experiences about the use of geomatic techniques in surveying and representing small archaeological artifacts, such as cuneiform tablets and other inscribed objects with cuneiform writing. Scanning by hand-guided structured light scanner and image processing on the 3D models permits a wider range of possibilities in respect to classical surveying methods and can help to improve the readability of the text

Analisi metrica in ambiente digitale di due carte pregeodetiche coeve condotta con metodologie non convenzionali

La cartografia storica digitalizzata e opportunamente georeferenziata risulta uno strumento fondamentale per l’analisi quantitativa dell’antico assetto del territorio e per lo studio delle relative dinamiche evolutive. Purtroppo però, la georeferenziazione non è sempre immediata per via di varie deformazioni contenute nelle carte, particolarmente quelle pregeodetiche. In questi casi risulta indispensabile una analisi metrica preventiva degli esemplari per l’individuazione delle principali problematiche presenti, analisi che può essere condotta con i moderni approcci digitali e supportata quando possibile da uno studio delle tecniche e delle strumentazioni di rilievo adottate dai cartografi autori. Il presente lavoro riguarda l’analisi di due carte coeve dell’area deltizia del fiume Po, redatte alla fine del XVI secolo da Ottavio Fabri (forse inventore della squadra zoppa, strumento la cui costruzione ed il cui utilizzo sono descritti in un manuale tecnico redatto dal medesimo), che in uno dei due esemplari ha operato insieme al collega Gerolamo Pontara. Sulla base delle informazioni deducibili sia dal manuale del Fabri sia dalle carte analizzate, nonché da un ulteriore esemplare redatto dai medesimi autori, è possibile ipotizzare che il rilievo sia stato sviluppato per sub-aree, rilevate con differenti metodi e strumenti, e forse anche in tempi differenti. Ciò suggerisce la necessità di adottare modalità non convenzionali per l’analisi e la georeferenziazione degli originali cartografici, per un’affidabile utilizzazione del prodotto-derivato ai fini di ulteriori studi territoriali di tipo geo-ambientale o storico ed economico in senso stretto.Digitized and georeferenced historical cartography is a fundamental tool for quantitative analysis and study of the ancient territory and its dynamics. Unfortunately, the georeferencing process is not always immediate due to some deformations that can affect the maps, especially the pre-geodetic ones. Therefore, in these cases most of all, a preventive metric analysis of the maps, combined with recognition of deformations, results necessary; the task can be performed by means of modern digital tools, and supported from preliminary studies on the original surveying instruments and methods. In this study, two contemporary late sixteenth century map of the Po delta area (Italy) are analyzed; they were made by Ottavio Fabri (author of a technical book, in which he describes construction modalities and use of the squadra zoppa, a mobile square maybe invented by him), with the colleague Gerolamo Pontara in one of the two samples. On the basis of information that can be deduced from the manual, and these maps and another map made by the same authors, a multi-stage survey can be inferred; in this case the survey could have be done in sub-areas, where different methods and instruments were used, maybe in different times. The fact suggests the necessity of adopting non-conventional modalities for the georeferencing of the map samples; in this way the new products can be effectively used for territorial researches of geo-environmental, historical and economic significance

Multitemporal Thermal Imagery Acquisition and Data Processing on Historical Masonry: Experimental Application on a Case Study

The recent improvement of infrared image quality has increased the use of thermography as a non-destructive diagnostic technique. Amongst other applications, thermography can be used to monitor historic buildings. The present work was carried out within the framework of the Horizon 2020 European project SHELTER, which aims to create a management plan for cultural heritage subject to environmental and anthropogenic risk. Among the chosen case studies is the Santa Croce Complex in Ravenna (Italy), which is exposed to different hazards, including flooding. The church has a peculiar architecture that develops below the street level, so the internal walls are affected by the deterioration caused by rising humidity. In such a case of advanced degradation, passive thermography cannot be used to its full potential. For this reason, an innovative methodology involving active thermography was first developed and validated with laboratory tests. Secondly, we conducted its first application to a real case study. With this purpose, an active thermography survey with forced ventilation was carried out to enhance different stages of material degradation by means of automatic classification of multitemporal data. These experiments have resulted in a method using an active thermal survey in a high moisture content environment to detect masonry degradation

Analysis of Pre-Geodetic Maps in Search of Construction Steps Details

Regeneration of ancient cartography in digital form is an interesting way not only to preserve historical cartographic documents as a cultural heritage, but also to allow new chances of understanding and using the historical information they record. In such a way, modern digital techniques, in particular study of map deformations and georeferencing, help in metric analysis of ancient cartography, and at last they appear to be useful for researchers to derive historical information for their studies, for example related to urban development or to geomorphological and environmental topics. The present research would give an example of the usefulness of the digital regeneration of ancient cartography, coupled with a visual analysis of the drawing. The study subject is a set of three maps portraying the Po river delta area (Northern Adriatic Sea, South of Venice, Italy) at the end of the 16th century, today preserved in the Venice National Archive. As they depict different landforms of the easternmost peripheral areas that today no longer exist, they are compelling for a geomorphological analysis, and they constitute a very interesting case study. The three map samples, drawn by three famous land surveyors, were analysed and cross-compared to try to find out information concerning the late Renaissance land-surveying techniques and the related cartographic draft steps. The kinds of evidence taken into account consist of technical signs preserved either in the palimpsest of the maps or in their final drawing. The meaning of some signs is explained by the Authors themselves in the legend, whereas the meaning of others can be inferred by an interesting methodological textbook, written by the main author to describe a new topographical instrument invented and used by himself. All these signs highlight a very interesting class of information related to the hidden steps of pre-geodetic map construction, which up to now is probably still poorly known and studied. Furthermore, an unusual methodological tool, never applied to this kind of researches up to now, is here proposed, i.e. the splitting of the original cartographic drawing in some subareas and its relocation to overcome the local gross topographic inconsistencies recorded on the maps