Comment on Underworld: How the Sinaloa Drug Cartel Digs Its TunnelsparentComments−hamiltonkibbe11ySurvey equipment. RTK GPS for position reference and heading on the surface, and lasers. Lots of lasers.see e.g. http://www.leica-geosystems.us/en/Tunnel-surveys_1693.htm
Comments
Survey equipment. RTK GPS for position reference and heading on the surface, and lasers. Lots of lasers.
see e.g. http://www.leica-geosystems.us/en/Tunnel-surveys_1693.htm