The use of microwave and radar sensors in the nondestructive evaluation (NDE) of damaged materials and
structures has been proven to be a promising approach. In this paper, a portable imaging radar sensor utilizing
10 GHz central frequency and stripmap synthetic aperture radar (SAR) imaging was applied to steel and wood
specimens for size and range determination. Relationships between range and properties of SAR images (e.g.
maximum amplitude and total SAR amplitude) were developed and reported for various specimens including a
steel bar (2.5 cm by 2.5 cm by 28.5 cm), a wood bar (2.5 cm by 2.5 cm by 28.5 cm), a steel plate (39.7 cm by
57.9 cm by 1.75 cm), and a wood board (30.5 cm by 30.5 cm by 1.8 cm). Various ranges from 30 cm to 100 cm
were used on these specimens. In our experiment, attenuation of radar signals collected by the imaging radar
system on different material specimens was measured and modeled. Change in the attenuation of maximum SAR
amplitude was observed in different materials. It is found that SAR images can be used to distinguish materials
of different compositions and sizes.
|