“…On the other hand, ERT is utilised to recognise geological structures [14][15][16], such as aquifers, aggregates, and metal deposits [8,13,17]. With ECT, the electrical permittivity is determined [18][19][20], but with EIT and ERT, the conductivity is reconstructed [2]. Apart from electrical tomography (EIT, ECT, ERT) [15] and computed tomography (CT) [21], there are numerous other varieties, which can be classified according to the physical phenomenon used: X-rays [22], sound waves [23], magnetism [24][25][26], electromagnetic waves, and visible light [27].…”