The development of Ground Probing Radar (GPR) in the investigation of masonry arch bridge systems has been restricted due to the requirement of specialist interpretation of the data. There is therefore a need for a method of simulation which aids the interpretation of GPR surveys. The method of convolution allows rapid simulation of varying geometries and material properties to be investigated. The combination of digital GPR systems along with simulation software will help a better engineering assessment to be made of the many masonry arch bridge systems now under review in the UK at the present time.