The number of rail passenger and miles travelled has dramatically increased over the past 15 years. Network Rail is the operator of the UK infrastructure network and is responsible for managing over 32,000 km of track. In order to maintain the required standards of comfort and safety Network Rail spends over one billion pounds (sterling) each year on maintenance alone. Traditional methods of determining when maintenance was required were time consuming and expensive, which lead to the use of non-destructive testing (NDT), particularly GPR, as a method of monitoring track conditions.
