An ASV for coastal underwater archaeology: The Pladypos survey of Caesarea Maritima, Israel

摘要

Coastal underwater archaeological sites are by nature dynamic, and often subject to disturbance from the action of waves, currents, sediment, and human activity. The need to document such sites comprehensively, accurately, and quickly has been the driving force behind technological advances in pre-disturbance site mapping since the 1960s. Certain challenges remain constant: the need for technology to be affordable and robust, with efficient post-processing as well as data acquisition times. Non-engineers must be able to interpret the results and publish them according to archaeological conventions. Large ancient shallow water port sites, submerged settlements, and landscape surveys present additional difficulties because of the volume of data generated. In this paper we present initial results of the first season of an expedition to map the submerged Herodian structures at Caesarea Maritima, Israel, using a robotic vehicle, the Autonomous Surface Vehicle (ASV) Pladypos, which was developed to address these challenges. This vehicle carries high-resolution imaging and remote-sensing tools to produce photomosaics and microbathymetry maps of the seafloor, as well as performing precise georeferencing. The Pladypos acquired a vast amount of georeferenced bathymetric and photographic data over several days in May 2014 and the results were later integrated into a GIS.