Improving Interferometric Synthetic Aperture Radar Performance Using Single and Multi-channel SAR Micro-Navigation and Optical Structure from Motion Techniques

Optimizing the use of Airborn inSAR System in the Northern environment

By Usman Iqbal Ahmed, PhD candidate SFU

Monday  April 24th 2023 11AM-12PM, North Boardroom of the YRC

Abstract:

Synthetic Aperture Radar (SAR) is the most versatile remote sensing tool because of its all-weather day and night capability. Interferometric SAR (InSAR) is a major technique in analyzing changes of the Earth surface over time, with applications including monitoring long term change (surface deformation, infrastructure change, glacier motion) and short term change (moving objects and ocean current etc). Detailed knowledge about platform motion and orientation (micro-navigation) is a critical factor in SAR and InSAR processing, for both space- and airborne SAR systems. In case of an airborne sensor the platform path is highly non-linear, thus repeat pass interferometry (used for change monitoring) is possible only with accurate micro-navigation knowledge, needed to correct platform motion artifacts in the InSAR output.  An optical Structure from Motion (SfM) photogrammetric system that is acquired simultaneously with the SAR data can not only provide complimentary optical data to the SAR data but also provide strong independent constraints on adjusting the aircraft micro-navigation parameters as well as providing Digital Elevation Models (DEMs) of the area of interest. The fusion of the SAR and Optical data can produce precise and accurate InSAR based change monitoring. In case of spaceborne SAR system, onboard determination of the sensor orientation is more critical than its position as motion of the platform is much smoother in contrast to the airborne case. The orientation of the sensor plays an important role in applications such as ocean current monitoring and moving object detection (using along track interferrometry). My research is focussed on utilizing accurate SAR sensor micro-navigation knowledge (position and orientation) for enhancing airborne and spaceborne InSAR outputs for long-term and short-term change monitoring.