Digital beamforming for near-space wide-swath SAR imaging

Inspired by recent advances in near-space technology and synthetic aperture radar (SAR) technique, this paper presents one digital beamforming-based near-space wide-swath imaging technique. Near-space defined as the space region between 20 km and 100 km, which is above storms and not constrained by orbital mechanics like satellite or high fuel consumption like airplane. These advantages make many new capabilities that are not accessible to current spaceborne or airborne SAR being possible for near-space SAR. This also offers an opportunity to design new SAR imaging technique. This paper deals with conceptual design, as opposed to technological implementation. Multiple beams in azimuth are used to suppress the possible azimuth ambiguities for near-space high-resolution and wide-swath SAR imaging. An example near-space wide-swath SAR is conceptually designed. Simulation results show that the combination of digital beamforming technology and near-space platform can provide a promising solution for remote sensing applications.