Radar Model Correction Of Asteroid 4179

Asteroid 4179 Toutatis has been modeling by ground-based radar observations until Dec 13 th, 2012, when distinct optical images of Toutatis was captured by Chang’E-2’s flew by at the shortest range for the first time. It was the first time human being observe near earth asteroid at such a short distance via optical devices, the CMOS camera on CE-2 captured distinct images of Toutatis. Scientists accumulated a lot of ground based radar data of asteroid 4179, and bu ilt a three-dimensional model of Toutatis, we call this model the radar model in this paper. The surface details of optical images are abundant enough to reinforce the radar model descriptions of Toutatis’ s surface structure. Under this context, we customized a method of frequency domain data fusion.Firstly, two-dimensional images under different illuminant conditions and rotate states were generated. Then, invariant moment was adopted to normalize the generated images and optical image. Hereby, the generated images and optical image hold the same scale and centroid. The asteroid radar image and visible light image positioning. And the voronoi was used to get a connection between radar model vertices and optical image pixels.Secondly, the depth information of optical image is needed because optical image is two-dimensional and radar model is three-dimensional. The method shape from shading was adopted to compute the depth map of optical image.Finally, a data fusion method was employed to integrate the deta iled information of the depth information of optical image and radar model. In the frequency domain the high spatial frequencies are related to the details of the shape, low spatial frequencies are related to the coarse shape information. The detailed shape information of the optical is abundant. In this paper, by using this kind of thought in the frequency domain to the depth of the radar model of frequency domain information and optical image depth information through high-pass filter, a more accurate model with abundant surface characteristics had been resulted.