S. Palm

The image-based acquisition of the current situation in urban areas is essential for various applications. In contrast to the typical SAR acquisition geometry from a single aspect on linear flight trajectories, this work considers mapping a small-scale area by data acquisition from various aspects on circular flight trajectories (CSAR). To meet the high requirements of aligning a narrow radar beam continuously to the point of interest during low-altitude circular flights, an automatic beam stabilization has been developed and operationally tested. A new and very broadband frequency-modulated SAR (FMCW) in the millimeter wave domain (mmW) at 94 GHz enables ultra-high-resolution imaging, and the compact design allows its operation on small aircraft. Dynamic visualization of the illuminated scene, similar to a video, is realized by a developed focusing method optimized for the unique acquisition geometry by processing overlapping subapertures (ViCSAR). 3d reconstruction of individual objects is achieved with single-channel data by extracting the movement of scattering centers on the SAR image sequences. To validate the CSAR methods, experimental measurement flights were carried out along circular flight trajectories with an ultralight aircraft (94 GHz FMCW SAR) over a suburban area. The results indicate that ultra-high-resolution SAR images with azimuth resolutions < 2 cm and 3D point clouds can be derived. Moving objects like vehicles are observable by their radar shadows in the coregistered and georeferenced image sequences. These methods can likely be used to derive radar signatures from buildings or ships and enable high-resolution SAR missions on unmanned platforms (UAVs).

Deutscher Luft- und Raumfahrtkongress 2022, Dresden

Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2022

Conference Paper

englisch

21,0 x 29,7 cm, 10 Seiten

urn:nbn:de:101:1-2022120911571093780943

Remote Sensing, Airborne mmW FMCW SAR, Video Circular SAR, Steerable antennas, UAV

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Palm, S. (2022): Mapping of Small-Scale Urban Scenes by Airborne mmW FMCW SAR on Circular Flight Trajectories. Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.. (Text). urn:nbn:de:101:1-2022120911571093780943.

09.12.2022