antoine@sep.stanford.edu

## ABSTRACTThel problem can be approximated using either Iteratively Reweighted Least
Squares methods (IRLS) with an appropriate weighting function or the Huber
misfit function with an appropriate solver. Comparisons of both methods
show that they give very similar results as they handle problems suited to ^{1}l properly.
In addition, the nonlinear scheme, using the Huber norm, generally converges better than
the linear IRLS algorithms on velocity-stack inversion. Finally, the Huber solver is far
easier to operate because it is sensitive to fewer parameters than IRLS.
^{1} |

- Introduction
- IRLS and the Huber solver, an overview
- comparing IRLS and Huber on a Geophysical problem
- conclusion
- REFERENCES
- About this document ...

4/27/2000