Comment on Underworld: How the Sinaloa Drug Cartel Digs Its TunnelsparentComments−mzs11yGPS does not work underground, you can for some impressive distance get away with a long cable and an external antenna, but there are also GPS repeaters available.
Comments
GPS does not work underground, you can for some impressive distance get away with a long cable and an external antenna, but there are also GPS repeaters available.