Underwater Photogrammetric Recording at the Site of Anfeh, Lebanon

Abstract

This chapter considers the application of underwater photogrammetry to record and document the underwater cultural heritage at the site of Anfeh in North Lebanon. Although photogrammetry has become a standard procedure in the field of maritime archaeology worldwide, this is the first use of this recording method in the country. The research context is presented, followed by the methodology adopted according to the particularities of the site and then the results of work undertaken over two campaigns: one in 2016 and one in 2017. The main aims in this chapter are to demonstrate the advantages of a low-cost and time-effective method of documenting sites, where the funding prohibits the use of more expensive geophysical equipment. The application of multi-image photogrammetry as a recording technique at Anfeh has merit in providing global access to artefacts in their in situ context. The results generated from 3D data were particularly informative to the study of a substantial collection of anchors of different types and sizes, without removing them from their underwater context. By calculating volume from the 3D scan, an estimation of the weight of these could be thus achieved and will serve in future analysis of the vessels plying the maritime routes at Anfeh. KeywordsUnderwater archaeology · Maritime material culture ·

Measuring Change Using Quantitative Differencing of Repeat Structure-From-Motion Photogrammetry: The Effect of Storms on Coastal Boulder Deposits

“…Lightroom is professional-grade software for photographic catalog management and bulk processing, which in addition to having powerful processing algorithms, is relatively inexpensive and user-friendly. Thus, it is often used in scientific photogrammetry for both image correction [35] and lens distortion correction [33,107]. The image corrections employed in this study were simple and uniform across the images: the contrast was increased to +30, and clarity (a mid-tone contrast enhancement) was increased to +25.…”

“…UAVs and structure-from-motion (SfM) photogrammetric software have become go-to tools for monitoring hazardous locations such as landslides [6][7][8][9][10][11][12] and subsidence/sinkholes [13][14][15]. These technologies have also been widely adopted in coastal erosion [16][17][18], marine science [19][20][21], both marine and terrestrial ecology [22][23][24][25][26][27], archaeology [28][29][30][31][32][33][34][35], and civil engineering [36][37][38][39][40].…”

A Semi-Automatic-Based Approach to the Extraction of Underwater Archaeological Features from Ultra-High-Resolution Bathymetric Data: The Case of the Submerged Baia Archaeological Park

“…In the case of passive sensors, techniques based on optical sensors are generally used. These can be used (i) from above, as in the case of derived bathymetry from aerial, drone, or satellite images [20][21][22][23][24], or (ii) from operators, boats, and ROVs (Remotely Operated Vehicles), as in the case of the analysis and reconstruction of submerged features using three-dimensional photogrammetry [25][26][27][28]. The active sensors used in RS UCH include the use of electromagnetic and sound waves (sonar), such as (i) single-and multi-beam echosounders, (ii) side-scan sonar, (iii) laser scanners (often combined with optical imaging), (iv) sub bottom profiler, (v) marine magnetometry, and (vi) depth geoelectrics [18,[29][30][31][32][33][34][35][36][37][38][39][40][41][42].…”

Dry‐lab benchmarking of a structure from motion workflow designed to monitor marine benthos in three dimensions

“…Other factors, such as the photograph capture strategy, camera settings and the lighting conditions have a direct impact on photograph, and therefore model, quality. Furthermore, in an underwater environment the characteristics of the object being surveyed (such as colour, orientation and surroundings), the physical characteristics of the water (for example, visibility, optical noise, light absorption and colour loss), the conditions on the day of the survey (weather, wind and currents) and the dive‐time limitations are key considerations (Menna et al., 2018; Semaan and Salama, 2019). Simply collecting photographs and processing them with user‐friendly SfM software may produce a 3D model, but that model is not necessarily the best 3D representation that is achievable given the available equipment.…”