Ultra-high resolution SAR in lower terahertz domain for applications in Mobile Mapping

Mobile Mapping is currently dominated by optical camera or laser based systems. Due to new semiconductor technologies, compact and light weight FMCW radar systems in the lower terahertz domain become applicable for such scenarios. With constant increasingly higher resolution capabilities in the subcentimeter domain such radar sensors could supplement existing sensor suites in challenging environments. Their electromagnetic waves exhibit only low absorption due to smoke, fog and dust and are independent from sunlight. Data were collected with the Miranda 300 GHz radar system in SAR mode with 30 GHz bandwidth mounted on a platform in a conventional van. Preliminary results from terahertz SAR data were processed using a time domain approach finally reaching a 5 mm resolution. The SAR system's ability of resolving very small metallic objects placed in the scenario was validated. Details in the SAR images are disclosed in unprecedented quality in terms of radar imaging. Objects down to a radar cross section of -43 dBsm could be resolved.