A three-dimensional imaging method for ice-sounding radar

Polar regions are an important component of the Earth’s environmental system. It is of great significance to detect polar ice layers. Nowadays, as for polar ice detection, traditional radar systems obtain two-dimensional ice layer information in range and azimuth direction. In order to obtain richer three-dimensional (3D) ice layer information, it is necessary to study 3D synthetic aperture radar (SAR) imaging system. This article proposes an airborne SAR system with an antenna array along cross-track to obtain 3D echo signals and perform focusing processing. A traditional 3D imaging method is back projection (BP) algorithm, which is applied to spaceborne ice-sounding SAR system. This article proposes a 3D imaging algorithm based on the inverse scaled Fourier transform (ISFT). 3D imaging is achieved through range and azimuth consistent compression, range ISFT, azimuth compression, cross-track phase compensation and cross-track Fourier transform. The effectiveness of the algorithm was verified through point target simulation. It is suitable for imaging in shallow ice layer below the antenna array. Compared to BP algorithm, this algorithm has higher computational efficiency.