This aerial satellite image provides a high-resolution view of the context of Stonehenge today, using Earth imagery sensors from the Airbus Defense & Space Pléiades satellite.

Ground-penetrating radar was used to reveal these underlying structures using noninvasive archaeological methods.

A four-year underground mapping project at Stonehenge was completed recently, yielding new maps and discoveries. The project used ground-penetrating radar, high-resolution magnetometers and other remote-sensing equipment to map the area to a depth of roughly 10 feet.

The Stonehenge Hidden Landscape Project was led by researchers from the U.K.'s University of Birmingham and Austria's Ludwig Boltzmann Institute for Remote Sensing and Virtual Archaeology. The goal was to provide “a rigorous analysis of wider landscape structures in relation to the emerging complexity of the archaeological evidence.” The goal of virtual archaeology is to explore a site thoroughly, using noninvasive methods.

The researchers dismiss prior underground mapping efforts as monument-focused, whereas their approach was extensive and methodical to reveal the overall spatial framework of the site. Nearly 3,000 acres have been surveyed, providing the means to excavate the area virtually.

For details of the methods and resulting maps from the geophysical and remote sensing survey, visit the Stonehenge Hidden Landscape Project website at http://lbi-archpro.org/cs/stonehenge/index.html.

A new BBC Two series, titled Operation Stonehenge: What Lies Beneath (http://www.bbc.co.uk/programmes/b04hc5t9), details how technology is reshaping how archaeologists understand Stonehenge’s landscape.

Sources: Airbus Defense & Space, Pléiades satellite image, and The Stonehenge Hidden Landscape Project