Medieval Archaeology Under the Canopy with LiDAR. The (Re)Discovery of a Medieval Fortified Settlement in Southern Italy

Abstract

Despite the recognized effectiveness of LiDAR in penetrating forest canopies, its capability for archaeological prospection can be strongly limited in areas covered by dense vegetation for the detection of subtle remains scattered over morphologically complex areas. In these cases, an important contribution to improve the identification of topographic variations of archaeological interest is provided by LiDAR-derived models (LDMs) based on relief visualization techniques. In this paper, diverse LDMs were applied to the medieval site of Torre Cisterna to the north of Melfi (Southern Italy), selected for this study because it is located on a hilly area with complex topography and thick vegetation cover. These conditions are common in several places of the Apennines in Southern Italy and prevented investigations during the 20th century. Diverse LDMs were used to obtain maximum information and to compare the performance of both subjective (through visual inspections) and objective (through their automatic classification) methods. To improve the discrimination/extraction capability of archaeological micro-relief, noise filtering was applied to Digital Terrain Model (DTM) before obtaining the LDMs. The automatic procedure allowed us to extract the most significant and typical features of a fortified settlement, such as the city walls and a tower castle. Other small, subtle features attributable to possible buried buildings of a habitation area have been identified by visual inspection of LDMs. Field surveys and in-situ inspections were carried out to verify the archaeological points of interest, microtopographical features, and landforms observed from the DTM-derived models, most of them automatically extracted. As a whole, the investigations allowed (i) the rediscovery of a fortified settlement from the 11th century and (ii) the detection of an unknown urban area abandoned in the Middle Ages.

The mapping of forested archaeological sites using UAV LiDaR. A feedback from a south-west France experiment in settlement & landscape archaeology.

“…However, unlike the landscape restitution made possible by LiDaR at other sites (Gabellone et al 2017;Masini et al 2018), this survey does not reveal any other remains in the immediate vicinity of this church. No topographical anomalies can be identified and interpreted as remains of settlement, road network or agrarian development.…”

ALS-Based Detection of Past Human Activities in the Białowieża Forest—New Evidence of Unknown Remains of Past Agricultural Systems

“…Since 2016, these works have also been carried out in south-eastern Poland-mainly In the present study, the first of its kind on such a large scale in the BF, we collected data for the entire area by utilizing Light Detection and Ranging (LiDAR) technology mounted on an aircraft, also known as an Airborne Laser Scanning (ALS) system. In many recent archaeological projects, ALS was one of the leading methods [26][27][28][29][30][31][32][33][34][35]. In Europe, numerous archaeological projects use public ALS data [13], but their utility for archaeological purposes was often low (approximately 1 pts/m 2 (points per square metre) or less), which means that other solutions, such as those dedicated to archaeology but also for natural research data acquisition, are necessary.…”

Identifying Linear Traces of the Han Dynasty Great Wall in Dunhuang Using Gaofen-1 Satellite Remote Sensing Imagery and the Hough Transform

“…Remote sensing (RS) provides a rapid and low-cost way of exploring, mapping and monitoring archaeological features of interest (AOIs) across the world [29]. Research that involves the identification of AOIs increasingly employs aerial photographs and spy satellite images [30][31][32][33] as well as multispectral and hyperspectral imagery [34][35][36][37][38], SAR data [39][40][41][42], and LiDAR products [43][44][45]. RS has unique advantages for detecting the large archaeological sites such as the Silk Road, Grand Canal, Nasca Lines and Great Wall [4].…”