It is a challenge to evaluate the conditions of railway track without interruption of regular traffic. In this paper, the authors introduce the detection of cavities under the railway substructure by using forward-loo...It is a challenge to evaluate the conditions of railway track without interruption of regular traffic. In this paper, the authors introduce the detection of cavities under the railway substructure by using forward-looking ground penetrating radar (FLGPR). Main advantages of FLGPR are that such a system can illuminate a large area and can stand off a long distance over its down-looking counterpart. Two methods, frequency wave-number (F-W) synthetic aperture imaging (SAI) and beam-forming by delay and sum (DAS), are applied to process the collected data. Analysis and measuring show that the distinct radar image of the cavity beneath the substructure 1.2 m deep can be formed by these two methods.展开更多
基金This work was supported by the National Nature Science Foundation of China under Grant No. 60472014.
文摘It is a challenge to evaluate the conditions of railway track without interruption of regular traffic. In this paper, the authors introduce the detection of cavities under the railway substructure by using forward-looking ground penetrating radar (FLGPR). Main advantages of FLGPR are that such a system can illuminate a large area and can stand off a long distance over its down-looking counterpart. Two methods, frequency wave-number (F-W) synthetic aperture imaging (SAI) and beam-forming by delay and sum (DAS), are applied to process the collected data. Analysis and measuring show that the distinct radar image of the cavity beneath the substructure 1.2 m deep can be formed by these two methods.