Fundamentals of SAR

Since the 1930s, radar, as an active electromagnetic sensor, has been widely used and developed for detecting, imaging, and locating reflective objects [1]. The target detection accuracy of traditional radar primarily depends on the physical aperture of the antenna, which limits the resolution performance of radar in the vertical direction of the beam. To overcome this limitation of traditional radar, Carl Wiley from Goodyear Aerospace in the United States first proposed the concept of synthetic aperture radar (SAR) in 1951 [2].