Improved cross-range resolution 2D Ground-based SAR to monitor remote objects

Document Type : Original Article


1 Geospatial engineering, University of Tehran

2 University of Tehran

3 School of Surveying and Geospatial Engineering, College of Engineering, University of Tehran, Tehran, Iran



This study demonstrates the effectiveness of the combination of two-dimensional mechanical rail with mmWave multiple-input multiple-output (MIMO) radar in order to improve the target detection resolution and increase the quality of the obtained synthetic aperture radar (SAR) image. Ground-based SAR (GBSAR) systems cover a wide range of applications in remote sensing. In the past few years, mmWave MIMO radars have shown interesting potential in this field due to their low cost, compact size, and high phase sensitivity. MIMO capability enables the angular discrimination of multiple targets in the same range as the radar sensor. However, current mmWave MIMO radars do not provide a high angular resolution that suffices in earth observation applications. To this end, we demonstrate the feasibility of combining mechanical rail and MIMO radars to obtain better cross-range resolution. Our experiments show that the ground-based MIMO SAR can obtain about 20 times better cross-range resolution than MIMO radar while improving the image quality with more than 10 dB improvement in the peak sidelobe ratio (PSLR) and signal-to-clutter ratio (SCR). Moreover, we provide a deeper investigation and comparison between the MIMO GBSAR and conventional monostatic GBSAR images. According to the results, MIMO GBSAR provided a similar angular resolution and PSLR but with a lower SCR than the monostatic GBSAR. The effects of mechanical rail instability are also investigated. According to the obtained results, the rail’s instability causes around a 5 dB decrease in the obtained SAR image’s focusing capability.