Imaging rover technology: characteristics, possibilities and possible improvements

The terrestrial photogrammetric survey allows to acquire geometric characteristics of objects quickly and with handy and inexpensive hardware. Traditionally, these measurements require some hours of time between the choice of the acquisition points, the setting up of the camera, the survey of the topographic support network and subsequent processing of the acquired data. The upcoming of advanced algorithms such as "structure from motion" (SFM) [1] and the recent availability of optical cameras with increasing resolution combined with increasing resources of mass storage [1], make it possible to create dedicated hardware with potentials not possible with these technologies so far. Of particular interest in this field is the coming of so-called "imaging rovers", i.e. cameras that allow simultaneous acquisition of multiple images, covering a 360-degree panorama and in some cases, directly positioned thanks to GPS/GNSS differential receivers with centimeter accuracy. The recent availability of these innovative techniques requires careful verification to assess their capabilities, accuracy, precision and possible limitations. This work presents the first systematic verification of one of these latest generation devices in different conditions and for different applications. It has been verified that in many cases it is possible to obtain three-dimensional surveys quickly with information contents comparable to those of more expensive and less handy instruments such as terrestrial laser scanning. The development of these techniques could lead to operational simplifications and greater efficiency also in complementarity with the reliefs from UAVs that, as it's well known, show some limitations in the so-called urban canyons

Use of the sensors of a latest generation mobile phone for the three-dimensional reconstruction of an archaeological monument: The survey of the Intihuatana stone in Machu Picchu (Peru')

The survey of archaeological monuments presents particular needs and difficulties. Such surveys must in fact be as complete, geometrically correct and accurately geo-referenced as possible. These needs, however, often face problems of difficult accessibility, the need for rapid timing and complex logistical conditions. The latest generation of mobile phones are equipped with ultra-high resolution cameras up to 100 megapixel. Although they do not have the geometric characteristics of professional cameras, they can be used advantageously for the reconstruction of three-dimensional models using Structure from Motion methodologies . At the same time, the latest mobile phones are equipped with GPS/GNSS chips that allow a postprocessing of their positioning allowing to reach decimetric/centimetric accuracies. The use of sensors integrated in a mobile phone greatly simplify the survey both in terms of transportability but also in terms of authorizations by the competent authorities as the equipment is exactly the same that most tourists who visit the sites themselves bring with them. The approach proposed and made possible by these combined features in a latest generation mobile phone have been tested for a rapid survey of the Intihuatana stone in Machu Picchu (Peru), a site with considerable logistical and organizing complexity

Tecniche di fotogrammetria digitale applicate alle immagini da satellite

Dottorato di ricerca in scienze geodetiche e topografiche. 12. ciclo. Tutore G. Lucarelli. Cotutore M. FianiConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

ACYOTB Plugin. Tool for accurate orthorectification in open-source environments

High-resolution satellite images must undergo a geometric rectification process in order to be used for metrical purposes. This operation, called orthorectification, is necessary because of deformations mainly due to camera distortions and acquisition geometry. To correctly orthorectify an image, it is necessary to accurately reconstruct the photogrammetric-acquisition characteristics and the image position with respect to a reference system connected to the ground. This operation, called orientation, can be done using various mathematical models such as rigorous, rational polynomial function (RPF), and rational polynomial coefficient, or, according to some authors, rapid positioning coefficient (RPC) models. Orientation and orthorectification are usually performed within specific commercial software, but in QGIS, these complex operations can be performed using the open libraries of the Orfeo Tool Box (OTB). Unfortunately, instructions given by OTB developers lead to scarce results. In fact, the procedure proposed in OTB does not allow for the full exploitation of the potential of RPC models, on which OTB itself is based. As OTB is open-source software, a plugin was developed to overcome these limitations and exploit its full potential. In fact, OTB interfaces are unfortunately essential, and some necessary functions are missing. Therefore, a new QGIS plugin was developed in order to run the entire process in the most photogrammetrically and statistically correct way, and, at the same time, to simplify the relative procedures

Boolean logic model for an environmental protection plan on a local administration territory

Site selection for waste disposal is a complex task that should meet the requirements of communities and stakeholders. In particular the problems of disposal of damp olive residues and the wastewater left over from the mechanical pressing of the olives has induced the local administration âCittà Metropolitana di Roma Capitaleâ, following the directives of the law nË 574/96, to individuate the areas in which is permitted to spread the refuse to be used as compost; such refuse must respect the requirements as to âqualityâ as defined by the characteristics established by the law of October 19, 1984, nË 748, and its successive modifications. The areas in question have been determined by carrying out a comparison between the maps of the hydrological network, the morphology of the terrain, and that pertaining to protected areas, paying particular attention to terrains with a higher permeability in order to avoid the seepa ge of the residue waters into the underground water table

Suitability of averaging GPS/GNSS paths to build geometrically correct digital road maps

At present, almost all vehicles have one or more GPS receivers on board. Usually these receivers work in point positioning mode, with deviations of several meters in planimetry and even higher in altitude. Such accuracy is not sufficient for the representation of the road network, both for assisted and automatic navigation purposes and for the creation or updating of large-scale maps. Many free cartographic sources are based on the idea that the continuous repetition of tracking with point positioning receivers makes the measurements converge towards results closer to the actual position of the roads travelled. Here we have experimented whether, by averaging the results of hundreds of tracks found on the same route, we can arrive at accuracy compatible with those needed for navigation and cartography that we have set here compatible with that for the traditional cartography scale 1:5000. The results show that in good conditions of visibility of the sky good results are obtained by averaging a limited number of tracks, more paths are needed in urban areas, while results are not reliable in areas with dense vegetation cover

Boolean logic model for an environmental protection plan on a local administration territory

Site selection for waste disposal is a complex task that should meet the requirements of communities and stakeholders. In particular the problems of disposal of damp olive residues and the wastewater left over from the mechanical pressing of the olives has induced the local administration âCittà Metropolitana di Roma Capitaleâ, following the directives of the law nË 574/96, to individuate the areas in which is permitted to spread the refuse to be used as compost; such refuse must respect the requirements as to âqualityâ as defined by the characteristics established by the law of October 19, 1984, nË 748, and its successive modifications. The areas in question have been determined by carrying out a comparison between the maps of the hydrological network, the morphology of the terrain, and that pertaining to protected areas, paying particular attention to terrains with a higher permeability in order to avoid the seepa ge of the residue waters into the underground water table

The contribution of open-source gis software and open spatial data for the re-evaluation of landslide risk and hazard in view of climate change

Recent events, including the floods in central Europe in May 2021, have highlighted how climate change is giving rise to scenarios that were neither foreseen nor predictable. One problem this poses is the need to rethink the logic of various environmental constraints that are often based on return times of 20-50 years or 100-200. A single event does not change the statistical expectations for the recurrence of the event itself, but the recurrence of several extraordinary events in a few years is a clear indication of a changing trend. The prevention of the effects of such events is based on the definition of the areas at greater or lesser risk specifically based on the return times of the exceptional events, so it is foreseeable that a series of territorial plans, mostly carried out a few decades ago, will have to be updated or re-executed from scratch. These reworkings will be able to take advantage of the open-source software and open spatial data that have become available in the meantime, facilitating the entire process, and making it more open and shareable. In this paper we tested on a real case (the May 1999 pyroclastic flows in Campania, southern Italy) the actual possibility of implementing a model for forecasting such events using only open-source software and open data. It has been demonstrated that the entire process can be carried out using only open-source resources and it has been verified that the predictions of the hazard and risk model obtained with only input data prior to the event, give an output prediction that is significantly coincident with the events that actually occurred as documented by the authorities