GPR profiles of partially to completely unstratified geologic formations

We discuss 150 MHz GPR profiles of glacial till, reworked till, colluvium or decaying granite, which mainly contain random inclusions related to lithology, grain size, or water. The profiles contain numerous diffractions and limited stratification to possibly more than 40 m depth. The penetration, lack of dispersion, and lack of well developed asymptotes that originate from diffractions at depth suggest that volume scattering is present, but not a significant source of signal loss. The deep penetration may result from enhanced backscatter, by which rays propagating in opposite directions along the same and least lossy round trip path interfere constructively.