Researchers revealed the ancient Roman City Altinum in Northern Italy using infrared aerial photography. Due to a severe drought in 2007, the dryness of the landscape enabled the team from the University of Padua to see evidence of 2,000-year-old structures beneath the soil.
Altinum was both strategic and beautiful. The discovery of the Venetic funeral inscriptions show that it dates to 100 BC. Altinum plays an important role researchers say in the history of Venice because its inhabitants colonized the northern lagoon islands when fleeing from Barbarians from the 5th to the 7th centuries AD. Today, about 11% of the lagoon is permanently covered by open water, and around 80% consists of mud flats, tidal shallows and salt marshes.
Credit: Andrea Ninfo et al., Science (31 July 2009)
Researchers used near-infrared aerial photography combined with digital elevation modeling techniques to view the structures. Infrared photography is exquisitely sensitive to vegetation stress. It provides a unique view of the Earth’s vegetation and other features of the planet’s surface. This unique aerial view, created by a combination of wavelengths, gives researchers a means to better understand what is happening on the Earth’s surface. This allowed researchers to reveal archaeological features such as churches, city walls, gates and even a theater. The city was enclosed by walls and gates and was surrounded by a network of rivers and canals.
Remote Sensing including aerial photography and satellite imagery have become increasingly important tools for archaeologists, as these systems link information to precisely calibrated physical locations, and integrate information drawn from multiple sources. The usefulness of aerial photographs for identifying and analyzing archaeological sites was recognized from the early days of aviation and imagery is now available from an array of aircraft and high resolution satellite sensors such as GeoEye-1, QuickBird, IKONOS, Spot-5 and LIDAR that provide even greater potential for investigating and mapping archaeological sites.