For the new study, the researchers deployed a grid of ground-penetrating radar antennae, fixed to a cart and towed over the site by an all-terrain vehicle. They bombarded the site with radio wave pulses, taking measurements every 2 inches (6 cm) and reflecting off objects underground to a depth of 6.5 feet (2 meters), according to the study. This showed Falerii Novi's buried structures in high resolution and in three dimensions.The project also learned more about the underground plumbing of the city.
Each scan provided a "slice" that the researchers then stitched together to create the map. Thanks to the new data, a much sharper picture of the long-hidden city emerged. The exceptional resolution enabled the study authors to perform detailed architectural analysis that would otherwise have been possible only through excavation. One structure, to the west of the city's southern gate, was clearly a temple; "you can see steps leading up to it, the columnated courtyard around it and the altar," [Professor Martin] Millett said.
Background here and links. I repeat: non-invasive and non-destructive technologies are the future of archaeology.
Visit PaleoJudaica daily for the latest news on ancient Judaism and the biblical world.