More than 2,000 years ago, Baiae was perhaps the most splendid seaside resort in Italy. Wealthy statesmen such as Mark Antony, Cicero and Caesar were drawn to the natural springs of the Gulf of Naples and built luxurious villas with heated baths and mosaic-clad thermal pools. But over the centuries, this playground of the Roman nobility was submerged by volcanic activity and the accompanying rise in sea levels.
Today, Baiae is one of the few underwater archaeological parks in the world. 435 hectares are open to visitors to explore the remains of the old Roman city. But the special location brings with it special challenges: Because Baiae is a protected marine area, the site must be continuously monitored for damage caused by divers and changing environmental factors. On dry ground, you would simply install appropriate cameras and sensors. It’s harder under water.
While wired surveillance systems are the most reliable, they are difficult to maintain and have limited coverage, so they are not very flexible. Wireless systems, on the other hand, don’t work well in water because it interacts with the electromagnetic waves. Optical and acoustic signals are also only suitable for wireless underwater communication to a limited extent – factors such as water temperature, salt content and sea conditions can falsify the signals on the way between the transmitter and receiver.
“Underwater Internet” for control
In order to find a better solution, Barbara DaviddeItaly’s Commissioner for Underwater Cultural Heritage, with a group of experts led by Chiara Petrioli, Professor at Sapienza University and Director of the Spin off WSense, a start-up specializing in underwater surveillance. Petrioli’s team has developed a network of acoustic modems and wireless underwater sensors that collect environmental data and transmit it in real time to those responsible on land. “We can now monitor the construction site remotely at any time,” says Davidde.
The special thing about the system: It is based on algorithms based on artificial intelligence, which automatically adapt the information path, i.e. the communication between the nodes, to the respective sea conditions, so that the signal can reach up to two kilometers. Data between stations a kilometer apart can be transmitted at up to one kilobit per second, and at shorter distances tens of megabits per second, Petrioli explains. This bandwidth is sufficient to transmit environmental data collected by sensors anchored to the seabed, such as information on water quality, pressure and temperature, metallic, chemical and biological elements, as well as noise, currents, waves and tides.
The “underwater internet” in Baiae enables the experts, among other things, to continuously monitor environmental conditions such as pH and carbon dioxide levels remotely. These affect the growth of microorganisms, which in turn could attack the archaeological artifacts. But visitors to the underwater park could also benefit from the system in the future.
Interactive opportunities for tourists
Barbara Davidde assumes that the network will be available to tourists in the coming months. As they swim above the ruins, they can use waterproof tablets to communicate with each other while viewing 3D reconstructions of the ruins via augmented reality. “The underwater internet has made monitoring the archaeological site easier and more efficient,” says Davidde. “At the same time, we can offer the public a new, interactive way to explore the Baiae Underwater Park.”
Even with low bandwidth, this underwater wireless communication technology is extremely useful, especially for dynamic systems such as divers moving around while exploring a site. They can be accurately located over the network, which can be an advantage in an emergency.
AI-powered systems like this are already being used at several archaeological sites in Italy. They also have applications in many other areas, such as studying the effects of climate change on the marine environment and observing underwater volcanoes. Italy’s National Agency for New Technologies, Energy and Sustainable Economic Development is using the WSense technique to study how algae, aquatic invertebrates and coral in Santa Teresa Bay are adapting to climate change. And in Norway, they are used to monitor water quality and fish health on salmon farms.
“It’s not something a wired system can do,” says Chiara Petrioli, “but the flexibility of a wireless network is extremely valuable.”
(jle)
