Di Palma et alii manuscript delves into applying remote sensing and photogrammetry methods to document and analyze the castrum at the Umm er-Rasas site in Jordan. This research aimed to map all the known archaeological evidence, detect new historical structures, and create a digital archive of the site's features for study and education purposes [1].

Their research has been organized into two phases. The first one consisted of a remote sensing survey and involved collecting historical and modern aerial and satellite imagery, such as:  aerial photographs by Sir Marc Aurel Stein from 1939; panchromatic spy satellite images from the Cold War period (Corona KH-4B and Hexagon KH-9); high and very high resolution (HR and VHR) modern multispectral satellite images (Pléiades-1A and Pléiades Neo-4) [1]. This dataset was processed using the ENVI 4.4 software and applying multiple image-enhancing techniques (Pansharpening, RGB composite, data fusion, and Principal Component Analysis). Then, the resulting images were integrated into a QGIS project, allowing for visual analyses of the site's features and terrain. These investigations provided:

·         a broad overview of the site,

·         the discovery of a previously unknown archaeological feature (the northeastern dam),

·         a stage for targeted ground-level investigations [1].

The project's second phase was dedicated to intensive fieldwork operations, including pedestrian surveys, stratigraphic excavations, and photogrammetric recordings, such as: photographic reconstructions via Structure from Motion (SfM) and laser scanner sessions (using two FARO X330 HDR). In particular, the laser scanner data were processed with Reconstructor 4.4, which provided highly detailed 3D models for the QGIS database. These results were crucial in validating the information acquired during the first phase.

Overall, the paper is well written, with clear objectives and a systematic presentation of the site [2,3,10,11], the research materials, and the study phases. The dataset was described in meticulous detail (especially the remote sensing sources and the laser scanner recordings). The methods implemented in this study are rigorously described [4,5,6,7,8,9] and show a high level of integration between aerial and field techniques. The results are neatly illustrated and fit into the current debates about the efficacy of remote sensing detection and multiscale approaches in archaeological research.

In conclusion, this manuscript significantly contributes to archaeological research, unveiling new and exciting findings about the site of Umm er-Rasas. Its findings and methodologies warrant publication and further exploration.

References:

1.    Di Palma, F., Gabrielli, R., Merola, P., Miccoli, I. and Scardozzi, G. (2024). Study and enhancement of the heritage value of a fortified settlement along the Limes Arabicus. Umm ar-Rasas (Amman, Jordan) between remote sensing analysis, photogrammetry and laser scanner surveys. Zenodo, 8306381, ver. 3 peer-reviewed and recommended by Peer Community in Archaeology. https://doi.org/10.5281/zenodo.8306381

2.    Abela J. and Acconci A. (1997), Umm al‐Rasas Kastron Mefa’a. Excavation Campaign 1997. Church of St. Paul: northern and southern flanks. Liber Annus, 47, 484‐488.

3.    Bujard J. (2008), Kastron Mefaa, un bourg à l'époque byzantine: Travaux de la Mission archéologique de la Fondation Max van Berchem à Umm al‐Rasas, Jordanie (1988‐1997), PhD diss., University of Fribourg 2008.

4.    Cozzolino M., Gabrielli R., Galatà P., Gentile V., Greco G., Scopinaro E. (2019), Combined use of 3D metric surveys and non‐invasive geophysical surveys at the stylite tower (Umm ar‐Rasas, Jordan), Annals of geophysics, 62, 3, 1‐9. http://dx.doi.org/10.4401/ag‐8060

5.    Gabrielli R., Salvatori A., Lazzari A., Portarena D. (2016), Il sito di Umm ar‐Rasas – Kastron Mefaa – Giordania. Scavare documentare conservare, viaggio nella ricerca archeologica del CNR. Roma 2016, 236‐240.

6.    Gabrielli R., Portarena D., Franceschinis M. (2017), Tecniche di documentazione dei tappeti musivi del sito archeologico di Umm al‐Rasas Kastron Mefaa (Giordania). Archeologia e calcolatori, 28 (1), 201‐218. https://doi.org/10.19282/AC.28.1.2017.12

7.    Lasaponara R., Masini N. (2012 ed.), Satellite Remote Sensing: A New Tool for Archaeology, New York 2012.

8.    Lasaponara R., Masini N. and Scardozzi G. (2007), Immagini satellitari ad alta risoluzione e ricerca archeologica: applicazioni e casi di studio con riprese pancromatiche e multispettrali di QuickBird. Archeologia e Calcolatori, 18 (2), 187‐227. https://core.ac.uk/download/pdf/33150351.pdf

9.    Lasaponara R., Masini N., Scardozzi G. (2010), Elaborazioni di immagini satellitari ad alta risoluzione e ricognizione archeologica per la conoscenza degli insediamenti rurali del territorio di Hierapolis di Frigia (Turchia). Il dialogo dei Saperi – Metodologie integrate per i Beni Culturali, Edizioni scientifiche italiane, 479‐494.

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11. Poidebard A. (1934), La trace de Rome dans le désert de Syrie : le limes de Trajan à la conquête arabe ; recherches aériennes 1925 – 1932. Paris : Geuthner.