Ground-penetrating radar for railways

A GPR along the track reveals the condition of the ballast and the formation, where the eye only sees the surface.

THE METHOD

How it works

GPR antennas are installed on a frame fixed to a machine or a rail vehicle. As it moves along the track, it sends waves towards the ballast and the ground and records the reflections. The shape of the signals shows the ballast thickness, its level of fouling and the irregularities of the formation beneath the rails.

Each measurement is positioned along the track (chainage). The data is then analysed by Rail Track Analyzer (RTA), a subsidiary of Plasser & Theurer and a specialist in railway GPR, which turns it into standardised indicators. This method applies to ballasted track.

WHAT IT IS FOR

The problems the method solves

Know where the ballast is fouled and must be cleaned or renewed, instead of treating the track uniformly.
Detect wet or unstable zones of the formation, often the cause of geometry defects that return after each tamping.
Measure the ballast thickness along the whole line.
Complement visual inspection and spot measurements with a continuous view over several hundred kilometres.

WHAT YOU RECEIVE

The results we deliver

Standardised indicators

Indicator reports on ballast fouling, layer thickness and anomalies under the rails, presented in a comparable way from one section to the next.

Map along the track

Representation by chainage, with sections ranked by condition level to spot critical sectors at a glance.

Data for your systems

Georeferenced data, exportable to your asset-management tools, and optional 3D digital model.

The indicators follow RTA's method.

HOW TO USE IT

What this changes for your decisions

Maintenance programming based on the actual condition of each section.
Reports comparable from one campaign to the next, useful for tracking evolution and documenting funding needs.
Better targeting of tamping and ballast renewal, so less unnecessary work.
A baseline before and after renewal works.

OUR EQUIPMENT

The equipment selected

RAIL TRACK ANALYZER (RTA) · PLASSER & THEURER

Railway GPR system

Antennas, acquisition unit and cables designed for measurement on track, combined with specialist analysis.

At a glance

Frame-mounted antennas, suited to inspecting the ballast and the formation
Analysis and indicators produced by the RTA team
Campaigns grouped in a dry period to limit transport costs

Why this choice

The equipment and analysis come from a railway specialist, a subsidiary of Plasser & Theurer: the indicators produced follow a proven method and can be read by an infrastructure manager. We provide the organisation of the field campaign, local coordination and follow-up with the manager.

EMLID · GNSS RTK

Emlid Reach RS3

Precision GNSS receiver that completes the chainage referencing.

At a glance

Centimetre-level positioning with RTK
Registration of measurements to the track plans

Why this choice

It makes it possible to register the results to the track plans and chainage points, to find a sector to treat without ambiguity.

Equipment selected for our first campaigns, being acquired, rented or provided through partnerships depending on the instrument; availability is confirmed when the order is placed. Characteristics as stated in the manufacturers' data sheets; they depend on configuration and terrain.

LIMITS

What the method does not do

The method applies to ballasted track; it is not suitable for slab track.
It does not replace the measurement of track geometry (gauge, levelling, cant), which remains necessary.
The analysis is carried out by RTA: turnaround times take this into account.

A corridor or structure to inspect? Let's talk about your need.

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