Direction of arrival assessment in airborne ice-sounding synthetic aperture radar

We propose an algorithm to evaluate the direction of arrival (DoA) estimation in the cross-track dimension of an airborne pulsed ice-sounding synthetic aperture radar (SAR), formed by a non-linear array. The conventional methods process either simulated data, meaning a lack of real scenario, or collected over regions previously mapped, where a limited number of DoAs is found. In our technique, we combine the echoes of different transmitted pulses from a real data take above the sea surface, planned to vary the roll angle of the aircraft. Due to the mirror-like behavior of the sea, when echoes at different roll angles are summed, we obtain raw data or images with several DoAs, relative to the main axes of the aircraft. This method is used to assess the estimation algorithms and choose the optimal for Antarctic bedrock 3D-imaging, identifying the DoAs to shape the true bed topography.

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