RAIL RADAR is being used in Canada to pinpoint the location of faulty sub-surface ballast and missing or damaged sleepers.
The ground-penetrating radar uses a multi-channel surface-coupled antenna towed behind a road-rail vehicle to survey routes at line speed. A PC stores data on over 1600 track-km and generates reports. The data are used with differential GPS to produce a Ballast Fouling Index, highlighting where repair or replacement is needed.
Rail Radar, Canada