Moving Target Refocusing With the FMCW SAR System MIRANDA-35

Inverse synthetic aperture radar is a commonly adopted technique for producing high-resolution images of moving targets. This article investigates the imaging capabilities of high-frequency and high-bandwidth systems by means of two distinct experiments. The deployed sensor is the Fraunhofer FHR MIRANDA-35, a millimeter-wave synthetic aperture radar airborne system, which transmits frequency-modulated continuous-wave signals at the Ka-band and is capable of achieving centimeter resolution. The performances are assessed by comparing the derived estimates (e.g., radial velocity and acceleration, and dimensions) with independent ground measurements. The resulting accuracy can be summarized as follows: the mean value of the percent error is 2.05% and 2.11% for radial velocity and acceleration, respectively, and 4.27% for the target dimensions.