https://phys.org/news/2018-05-advanced-mobile-technology-underground.html

High-accuracy, 'virtual' excavations

The LARA system is a handheld, low-cost mobile device that enables field workers to 'see beneath the ground'. The device brings together Global Navigation Satellite System (GNSS) technology, 3-D geographic information system (GIS) technology and geospatial databases with computer graphics and augmented reality to render complex 3-D models of underground networks including water, gas, sewerage and electricity. GNSS technology includes Galileo and EGNOS as well as GPS.