Construction and application of tomographic SAR system based on GB-SAR system

Synthetic Aperture Radar (SAR) provides high-resolution images regardless of weather conditions and solar illumination. However, a SAR image projects the 3D distributed targets onto a 2D plane in range and azimuth. Tomographic SAR (TomoSAR) is a technique to generate 3D image by adding the vertical baselines to the conventional SAR image acquisition. TomoSAR has recently been used to map the internal structure of forests and the geometry of the buildings by using airborne and ground-based SAR systems. In this paper, we report the construction of a Ground-Based TomoSAR (GB-TomoSAR) system and explain the basic principle of the GB-TomoSAR focusing algorithm. A GB-TomoSAR experiment was performed on the rooftop of a building at Kangwon National University. Heights of various targets were measured by generating the slice images both in the horizontal and vertical direction, which well matched to the in situ data. The experimental image has limitations in the detection of trees due to temporal decorrelation during the 8 hours of acquisition for a single tomogram. In order to overcome this limitation, we are planning to enhance the scanning speed of GB-TomoSAR in the near future.