scholarly journals Preliminary Archeological Site Survey by UAV-Borne Lidar: A Case Study

2021 ◽  
Vol 13 (3) ◽  
pp. 332
Author(s):  
Marco Balsi ◽  
Salvatore Esposito ◽  
Paolo Fallavollita ◽  
Maria Grazia Melis ◽  
Marco Milanese

Preliminary analysis of an archaeological site requires the acquisition of information by several diverse diagnostic techniques. Remote sensing plays an important role especially in spatially extended and not easily accessible sites for the purposes of preventive and rescue archaeology, landscape archaeology, and intervention planning. In this paper, we present a case study of a detailed topographic survey based on a light detection and ranging (LiDAR) sensor carried by an unmanned aerial vehicle (UAV; also known as drone). The high-resolution digital terrain model, obtained from the cloud of points automatically labeled as ground, was searched exhaustively by an expert operator looking for entrances to prehistoric hypogea. The study documents the usefulness of such a technique to reveal anthropogenic structures hidden by vegetation and perform fast topographic documentation of the ground surface.

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 265
Author(s):  
Mihnea Cățeanu ◽  
Arcadie Ciubotaru

Laser scanning via LiDAR is a powerful technique for collecting data necessary for Digital Terrain Model (DTM) generation, even in densely forested areas. LiDAR observations located at the ground level can be separated from the initial point cloud and used as input for the generation of a Digital Terrain Model (DTM) via interpolation. This paper proposes a quantitative analysis of the accuracy of DTMs (and derived slope maps) obtained from LiDAR data and is focused on conditions common to most forestry activities (rough, steep terrain with forest cover). Three interpolation algorithms were tested: Inverse Distance Weighted (IDW), Natural Neighbour (NN) and Thin-Plate Spline (TPS). Research was mainly focused on the issue of point data density. To analyze its impact on the quality of ground surface modelling, the density of the filtered data set was artificially lowered (from 0.89 to 0.09 points/m2) by randomly removing point observations in 10% increments. This provides a comprehensive method of evaluating the impact of LiDAR ground point density on DTM accuracy. While the reduction of point density leads to a less accurate DTM in all cases (as expected), the exact pattern varies by algorithm. The accuracy of the LiDAR-derived DTMs is relatively good even when LiDAR sampling density is reduced to 0.40–0.50 points/m2 (50–60 % of the initial point density), as long as a suitable interpolation algorithm is used (as IDW proved to be less resilient to density reductions below approximately 0.60 points/m2). In the case of slope estimation, the pattern is relatively similar, except the difference in accuracy between IDW and the other two algorithms is even more pronounced than in the case of DTM accuracy. Based on this research, we conclude that LiDAR is an adequate method for collecting morphological data necessary for modelling the ground surface, even when the sampling density is significantly reduced.


2017 ◽  
Vol 38 (1) ◽  
pp. 97
Author(s):  
Gustavo Rodrigues Gimenes ◽  
Rone Batista Oliveira ◽  
Alessandra Fagioli da Silva ◽  
Luiz Carlos Reis ◽  
Teresinha Esteves da Silveira Reis

The slope of terrain represents a risk factor for mechanized harvesting, leading to impediments or restrictions on agricultural operations, or even to machines toppling over in the field. Recently, the Digital Terrain Model (DTM) has become widely adopted as one of the most viable techniques for obtaining slope and elevation. Therefore, this study aims to assess methods of acquiring DTMs to calculate the slope, and to determine the areas that are suitable and unsuitable for the operation of harvesters in the municipality of Bandeirantes (PR). Four methods were selected to produce DTMs for the construction of slope zoning maps applicable for harvester operations. The image sources included SRTM, ASTER GDEM, digitizing contour lines and kriging of spatial point data. After generating DTMs by the four different methods, the area suitable for the operation of harvesters was obtained based on the limits of operational slopes for harvesters in the literature. The high-resolution images, such as those obtained by scanning the contour lines and ASTER GDEM gave the best representation of the ground surface. Regardless of the method used to obtain the operational slopes, the municipality has a large area that is suitable for mechanized harvesting.


2011 ◽  
Vol 90-93 ◽  
pp. 2818-2821
Author(s):  
Dong Ling Ma ◽  
Jian Cui ◽  
Ning Ding

INPHO is foreign professional digital photogrammetry software, including aerial triangulation encryption, digital terrain model matching, the digital orthophoto rectification and image mosaic series modules. This paper, taking DMC image as a case study, according to production practice, states the method of making Digital Orthophoto Map (DOM) using all relevant modules of INPHO, and further points out several notes in the process of making DOM. Practice shows that making DOM using INPHO series software and paying attention to the mentioned precautions can speed up production rate, improve production efficiency, while its mode of operation is also greatly simplified compared with the normal mode of operation. It is a good way of making DOM.


Author(s):  
F. Fassi ◽  
L. Perfetti

<p><strong>Abstract.</strong> The paper presents the case study of the complete 3D survey of the area of the Fort of Pietole in Borgo Virgilio using the Leica Pegasus Backpack wearable Mobile Mapping System (MMS). Surveying the site is challenging because of its complex topology on the one hand (with notably narrow passages) and because of the presence of vegetation on the other. The framework within which this research takes place is the Fort of Pietole survey project that aims at the extraction of the Digital Terrain Model (DTM) of the area and the georeferencing of the fort defensive structures. The requirement of the project is the 3D reconstruction of the whole area at an accuracy that stands between a big scale environmental survey and a small-scale architectonic survey (1&amp;thinsp;:&amp;thinsp;500).</p> <p>The project is the opportunity to discuss the state of the art of wearable MMS, and to test the versatility and accuracy outcomes of the Pegasus Backpack under varying and challenging condition (indoor-outdoor, even-uneven pavement, satellite covered-denied areas) with the ambitious goal to use only the backpack MMS to record all the data from the DTM to the indoor narrow structures.</p>


2018 ◽  
Author(s):  
Jens Ingensand ◽  
Jean Christophe Foltête ◽  
Stéphane Cretegny ◽  
Nicolas Blanc ◽  
Sarah Composto

This paper describes a method that uses georeferenced landscape pictures extracted from open picture collections for the determination of the population's interest in spatial features. The automated method takes into account the coordinates of the camera position as well as the azimuth angle, the focal length and the crop factor in order to calculate a field of view using a digital terrain model (DTM). This field of view can thereafter be used for the determination of interest in spatial features. In a case study involving more than 3'000 georeferenced pictures we investigate the potential of the method.


2020 ◽  
Vol 15 (3) ◽  
pp. 34-46 ◽  
Author(s):  
Salvatore Antonio Biancardo ◽  
Francesca Russo ◽  
Rosa Veropalumbo ◽  
Viktoras Vorobjovas ◽  
Gianluca Dell’Acqua

The study of ancient stone pavements represents the necessary premise for planning and execution of treatments that considers the necessity of conservation. The approach to the integrated management of information derived through H-BIM has been applied to Via del Vesuvio, one of the main roads in the archaeological site of Pompeii in Naples, Italy. The digital terrain model was carried out using Autodesk Infraworks software. Then, using Autodesk Civil 3D and Revit software, the road was digitalized creating the 3D model that included road geometric information resulting from an on-site survey, material characteristics for each pavement layer, construction period and related construction cost information. Finally, based on the existing research works available in the literature review, using Autodesk Naviswork software, it was possible to implement in the 3D model the BIM fourth dimension, namely, the time related to the construction of Via Del Vesuvio in different eras. The interoperability between the adopted BIM authoring software was exploited. The adopted procedure can be considered a benchmark case in the technical literature of H-BIM for stone pavements, highlighting the advantages in the design field.


2018 ◽  
Vol 3 (2) ◽  
pp. 269-270 ◽  
Author(s):  
Andrew G. K. Smith

Horizon is a Geographic Information System (GIS) tool designed for archaeoastronomers investigating alignments of prehistoric monuments with astronomical phenomena (for example, rising and setting of the Sun, Moon and stars). It gets its name from its primary function, calculating accurate horizon profiles using Digital Terrain Model/Digital Elevation Model mapping data. More generally, it is a landscape visualisation tool which can generate full 360° panoramic scenes using 3D rendering techniques which may have some applications in the field of landscape archaeology.


Author(s):  
M. Piragnolo ◽  
S. Grigolato ◽  
F. Pirotti

<p><strong>Abstract.</strong> The goal of this work is to assess a method for supporting decisions regarding identification of most suitable areas for two types of harvesting approaches in forestry: skyline vs. forwarder. The innovative aspect consists in simulating the choices done during the planning in forestry operations. To do so, remote sensing data from an aerial laser scanner were used to create a digital terrain model (DTM) of ground surface under vegetation cover. Features extracted from the DTM are used as input for several machine learning predictors. Features are slope, distance from nearest roadside, relative height from nearest roadside and roughness index. Training and validation is done using areas defined by experts in the study area. Results show a K value of almost 0.92 for the classifier with best results, random forest. Sensibility of each feature is assessed, showing that both distance and height difference from nearest road-side are more significant than overall DTM value.</p>


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