Abstract :
Synthetic aperture radar (SAR) is an active microwave imaging sensor, which is capable of outputting high resolution radar images even if under extreme weather conditions. It can work in full time and in all weathers with far-range, broad sensing, multi-polarization, multi-brand, variable visual angle and high penetrabiLity characteristics, greatly enhancing the radar capabiLity of obtaining information. The antenna of SAR during imaging is required to keep moving rectiLinearly with constant speed, while the space craft´s body usually has irregular vibrations, which brings difficulty for stable imaging, so it is necessary to carry out motion compensating. In this paper, based on the motion parameters output from IMU on the space craft, real motion information of the centre of SAR antenna is calculated for motion compensating. First, vibration analysis is carried out by using finite element method to get the transfer function from IMU centre to SAR, and then motion transfer relationship is built between IMU and the antenna centre with consideration on the vibration and lever-arm effect. Simulation is given in typical vibration case, which could provide good reference for onboard SAR design and manufacture.
Keywords :
finite element analysis; microwave imaging; motion compensation; radar antennas; radar imaging; synthetic aperture radar; vibrations; SAR antenna; active microwave imaging sensor; finite element method; high resolution radar images; irregular vibrations; lever-arm effect influence; motion compensation; motion transfer relationship; multibrand; multipolarization; onboard SAR centre motion parameters; onboard SAR design; penetrability characteristics; synthetic aperture radar; transfer function; vibration analysis; weather conditions; Acceleration; Antennas; Equations; Finite element methods; Mathematical model; Transfer functions; Vibrations; Lever-Arm Effect; Space Craft; Synthetic Aperture Radar (SAR); Transfer Function; Vibration Analysis;
