Asteroid and comet shape modeling using overcomplete spherical bases
Abstract
Spherical harmonics form a complete basis on the sphere, i.e., they can present any squared-integrable function on the sphere given that the degree and order of the bases are enough. For this reason, it is convenient to represent asteroid or comet shapes using spherical harmonics. Nevertheless, it suffers some drawbacks when it comes to modeling the multi-scale local details of the shape. When the local irregularity is large, spherical harmonics representation will become less efficient and require large amount of coefficients. In this work, we will present a method for modeling the shape of asteroids and comets using so-called overcomplete spherical bases. That is, we combine both spherical harmonics for a global representation and spherical wavelets for local detailed modeling. Since spherical wavelets and spherical harmonics are both compete bases on the sphere, they form overcomplete bases. This method will bring some advantages to both the representation and analysis of the shape of asteroids and comets. The analysis capability comes from that the coefficients of the bases could be rotationally invariant, and the representation advantage comes from the compression capability of spherical wavelets.
- Publication:
-
EPSC-DPS Joint Meeting 2019
- Pub Date:
- September 2019
- Bibcode:
- 2019EPSC...13.1785X