Simulation of the Dual-Frequency Radar Image of Asteroid 2016 HO3 and Implication for Tianwen-2 Mission

In China's Tianwen-2 mission, a dual-frequency radar will be carried out to detect the asteroid 2016 HO3. The dual-frequency radar can acquire the information of the asteroid's surface and internal structure. There are few studies about the radar detection of the asteroid 2016 HO3 and it is unclear what information can be acquired from the radar images. In this article, the radar images of the asteroid under nadir and oblique observations are simulated with the two-scale model of the Kirchhoff approximation/small-perturbation method. The radar images at 900 and 150 MHz are simulated to study the backscattering from the asteroid's surface and the detectability of the internal structure in the asteroid. The influences of the asteroid characteristics, such as the shape, surface roughness, internally embedded object, and the loss tangent of the media, on the radar images and the detectability of internal structure are discussed under nadir and oblique observations. The simulations provide a reference for future data analysis in the Tianwen-2 mission.