WHERE CAN GPR BE UTILIZED?

As with all types of radar imaging, Ground penetrating radar delivers varying levels of accuracy according to the conditions.

SOIL PROPERTIES & GROUND MATERIAL
GPR works by sending a tiny pulse of energy in to the ground then recording the strength of reflected signals and time it takes them to return to the receiver. A scan includes a group of pulses over a single area. While some of the GPR energy pulse reflects back to the receiving antenna, some energy continues to travel through the material until it dissipates, or the scanning session simply ends. The rate of signal dissipation varies widely, depending on properties of the materials.

It can be put on a number of ground materials, including:

Soil,
Rock,
Ice,
Fresh water,
Pavement,
Concrete structures.
As  https://notes.io/qZwzj  enters a material with different dielectric permittivity or other electrical conduction properties, it produces a reflection. The strength, or amplitude, of the signal is the result of the contrast in the dielectric constants and conductivities between the two materials. A pulse moving from wet sand to dry sand will produce a very strong reflection, for instance, in comparison to the relatively weak reflection made by moving from dry sand to limestone.

DEPTH
The ground itself can limit how deep GPR signals penetrate up to 100 feet (30 meters) deep. The ground has electrical resistivity, which means it opposes the flow of electric energy to some degree. As the signal penetrates deeper, it naturally gets less effective. This depends mostly on the type of soil or rock being surveyed and the frequency of the antenna used. For example, the maximum penetration depth in concrete is usually about 2 feet. In moist clays and other high conductivity materials, GPR signals depth is significantly shallower, reaching about 3 feet (1 meter) or less.

WATER CONTENT
Dielectric permittivity of the substrate can be one factor.  https://anotepad.com/notes/pwa6hrph  is the ease with which materials become polarized. The number of water within the material greatly affects dielectric permittivity. Certain materials can become polarized in the current presence of an electric field.