On Orbital Determination of the Lunar-Based SAR Under Apsidal Precession

作者：Xu, Zhen; Chen, Kun-Shan^*; Liu, Guang

来源：IEEE Transactions on Geoscience and Remote Sensing, 2022, 60: 5228217.

DOI：10.1109/TGRS.2022.3176836

• Apsidal precession
• focusing quality
• geometric fidelity
• lunar-based synthetic aperture radar (LBSAR)
• orbital determination
• required accuracy

The signal propagation of the lunar-based synthetic aperture radar (LBSAR) is affected by perturbations of the lunar orbit, wherein the apsidal precession that exerts a significant impact on the LBSAR imaging performance of the LBSAR deserves special care. Accordingly, the orbital determination used to maintain well-focused quality and high geometric fidelity in the existing SAR system becomes critical for the LBSAR. In this article, through establishing criteria for the orbital determination of LBSAR based on its imaging performance under the influence of apsidal precession, we investigate the accuracy requirements for the LBSAR orbital determination in terms of the position and velocity determinations. Analysis results show that the required accuracy for the LBSAR position determination depends on the geometric fidelity in the range direction, while the accuracy requirement for the velocity determination is dominated by the azimuth positioning accuracy. The focusing quality is not a primary issue for the LBSAR orbital determination. In addition, the far look angle of LBSAR accounts for the highest accuracy requirement in the position and velocity determinations; thus, it can he treated as the optimum look angle for the LBSAR orbital determination. It is also found that both velocity and position determinations are challenging in the z-direction for the LBSAR.

• 单位
  桂林理工大学; 中国科学院; 汕头大学