Real Time Shape Reconstruction for Near Earth Asteroid Landing
21 Feb 2018 #Astrodynamics #Geometric Control #Geometric Mechanics #Python #C++ #Publication \[\newcommand{\bracket}[1]{\left[ #1 \right]} \newcommand{\parenth}[1]{\left( #1 \right)} \newcommand{\tr}[1]{\mathrm{tr}\negthickspace\bracket{#1}}\]Summary
In order to determine the shape of the asteroid, we model a laser ranging sensor (LIDAR) on a maneuvering spacecraft. The LIDAR is able to provide depth measurements of the surface of the asteroid. Given a set of depth measurements it is possible to compute the shape, and hence gravitational potential of the asteroid. Computing the shape of the asteroid on a continual basis avoids the long delay and computational complexity of current asteroid operations. Furthermore, the updated gravitational model enables a spacecraft to autonomously transition from a mapping orbit directly to landing.
We develop a method to incrementally update the shape of an asteroid model using LIDAR measurements. This incremental update occurs in real time and allows for responsive space missions around asteroids.
Basic procedure
We first begin by simulating LIDAR measurements around an asteroid
Each measurement defines a point that lies on the surface of the asteroid. Taking many measurements defines a point cloud which represents the surface shape.
The end goal is to define a surface mesh which represents the shape of the asteroid.
Downloads
A compiled version of the PDF is available above using the large PDF link.
All of the code used to generate the images are also available below.
Videos
Here are some selected videos demonstrating this process.
- Cube into Sphere - Here we show how a cube is incrementally turned into a sphere by incorporating measurements from the surface of the sphere.
- Sphere into Ellipse - Here we incrementally modify a sphere into an ellipse
- Castalia Shape Generation - Here we apply our incremental shape method to a high fidelity simulation around asteroid 4769 Castalia.