In recent years, GPR technology has been successfully used by TST Engineering for the investigation of railway infrastructure. This type of intervention uses hardware and software which is suitable for surveying large distances while avoiding any interruption of the railway’s normal use.

In the past, control and verification of railway ballast was carried out mainly through intrusive investigations. The process consisted of spot verification in relation to visually apparent problems which were detected. This approach has been found inadequate for several reasons:

- Railway use must be stopped;
- Long lead times;
- Only localized results.

Ensuring that the geometry of the railway remains unchanged is crucial for the safety of railway users. Mechanical stress creates instability in the sub-ballast and ballast to the point where it can cause structural failures and potential derailment. The use of radar technology, as a support for diagnosis and planning of interventions is widely used and appreciated throughout Europe. This technology allows TST to utilize non-destructive methods to collect a large amount of data in a short time while working without interrupting or altering the normal railway use. This unique system allows the collection and storage of all data in the subsoil combining this with real images of the corresponding surface. This information is collected by radar antennas mounted on trains that are able to survey the railway with speeds up to 160 km\h.