Cheng-Yen Chiang*
Innovation Frontier Institute of Research for Science and Technology, National Taipei
University of Technology, Taiwan
*dcychiang@ntut.edu.tw
摘要 (abstract)
Active microwave Synthetic Aperture Radar (SAR) has been increasingly developed for commercial purposes worldwide in recent years. In Taiwan’s third-phase national space mission, SAR has become one of the key projects for Earth observation. With the advancement of the Formosat-9 mission, a value-added product development program was initiated to address critical challenges, including the development of formation algorithms, definition of key parameters, prediction of image quality, and pre-release assessment of potential on-orbit SAR imagery prior to satellite launch.
To tackle these issues, a dedicated software-based SAR simulator was developed. SAR simulators generally fall into two categories: raw echo signal simulators and SAR image simulators. Due to the large data volume associated with remote sensing imagery, SAR image simulators are often preferred the second category despite their lack of electromagnetic (EM) signal-level information, such as phase data. Our SAR simulator employs a coherent simulation method, which incorporates several key characteristics. First, it integrates different types of objects while preserving all EM interactions. Second, it supports various data acquisition modes, including Stripmap, Spotlight and ScanSAR or even hybrid observation mode. Finally, it retains essential EM features and SAR geometry to ensure comprehensive simulation capabilities. The overall simulation architecture and its functionalities are presented through demonstrations.
One major application of the SAR simulator is target recognition, where multi-orientation images are generated for database establishment. Complex target interpretations, including multiple bouncing effects, are also demonstrated. Furthermore, ocean surface simulations under varying conditions, such as RMS height and correlation length, are used to analyze fundamental SAR statistical properties with different multi-look configurations. Finally, a case study of a cargo ship on the ocean highlights the simulator’s capability to handle fully polarimetric SAR data.
關鍵詞：SAR, echo simulation, image interpretation, fully-polarimetry.
發佈留言