‘The Rock’ Revealed by Radar, Lidar

In 1934, one of America’s most notorious underworld gangsters, Al Capone, was sent to Alcatraz, also known as “the Rock.” …

A group of researchers from Binghamton University, N.Y., used a combination of ground-penetrating radar, terrestrial lidar, and georectifications to develop a 3D model … [that] revealed a series of secret tunnels — possible escape routes — just centimeters beneath what was once the prison recreation yard.

Read the rest in the July 2019 issue of Photonics Spectra.