  This paper presents measures to reduce the computation time of automotive
synthetic aperture radar (SAR) imaging to achieve real-time capability. For
this, the image formation, which is based on the Back-Projection algorithm, was
thoroughly analyzed. Various optimizations were individually tested and
analyzed on graphics processing units (GPU). Apart from the time reduction
gained from these measures, the data size needed for processing was also
drastically decreased. With a combination of all measures, a high-resolution
SAR image of 30 m by 30 m that combines 8192 chirps can be reconstructed in
less than 30 ms using a standard GPU. It is thus demonstrated that a real-time
implementation of automotive SAR is possible.
