Inverse Problems and Machine Learning in Earth and Space Physics
Overall Course Objectives
This course covers advanced methods for inversion of geophysical and astrophysical data, including machine learning techniques. Case studies from a wide range of inverse problems in Earth and Space physics (e.g. seismic tomography, geomagnetism, exoplanets, ground penetrating radar, galactic emission spectra, gravity) are presented and solved. The emphasis in this course is on inversion methods that handle non-Gaussian noise and use of suitable a priori information to get the most out of the observed data.
Python will be used as a tool throughout the course.
See course description in Danish
Learning Objectives
- formulate and solve practical inverse problems with incomplete, noisy data
- use robust statistical methods to derive models from data, handling non-Gaussian noise
- use model regularization and a priori information during the inversion procedure
- explain how to select level of model regularization
- use of sparsity regularization methods
- explain the use of Bayesian methods for inversion of geophysical and astrophysical data
- use Markov-Chain Monte Carlo (MCMC) techniques to find probabilistic solutions to inverse problems.
- explain relevance of machine learning techniques to problems in Earth and Space physics
- use backpropagation methods to train feed-forward neural networks for solving inverse problems
Course Content
Theory:
Statistical data description, Maximum likelihood, Model non-uniqueness, null space and resolution, Bayes Theorem, Probabilistic Inversion, Supervised and Unsupervised Machine Learning
Methods:
Robust statistics for non-Gaussian errors, Annihilators, Model regularization, Trade-off curves, Generalized cross validation, Resolution matrix, Markov-Chain-Monte-Carlo (MCMC) methods, Sequential Gibbs sampling, Feed-forward neural networks, Training by Back-propagation, Stochastic gradient descent
Teaching Method
Lectures, exercises, projects.
Faculty
Remarks
The course is aimed at students who want competence in advanced inversion methods and machine learning for use in Earth and Space Physics.