Azimuth reconstruction demonstration using TerraSAR-X dual receive antenna mode

The paper presents the first spaceborne experiment of digital beamforming (DBF) in synthetic aperture radar (SAR) and its result. The DBF in future spaceborne SAR will be used to suppress azimuth ambiguities and to reconstruct Doppler spectrum from multiple spectra distorted by spectral aliasing due to spatial sub-sampling. TerraSAR-X dual receive antenna (DRA) mode provides two parallel datasets, which are the sum and difference signals of two receive antennas. For the DBF experiment, firstly, we recover each receive antenna signal from those datasets and carry the DBF experiment out with the recovered data. Therefore, this experiment contains the each channel data recovery and channel balancing as well as SAR imaging with DBF. The experimental results show the prominent performance improvement in the azimuth ambiguity level, compared to a conventional single antenna mode.