Inverse Methods

Two variational inverse methods have been implemented within Elmer/Ice to inverse either the basal friction coefficient field beta(x,y) or the fluidity parameter A(x,y,z). Both methods are based on the minimisation of a cost function that measures the mismatch between modelled and observed velocities. These two methods are:

  • the linear adjoint method, following Morlighem et al. (2010)
  • a Robin type method, from Arthen and Gudmundsson (2010)

More information will be put online later regarding the various solvers needed for inverse problems.

In the meanwhile some info about the Robin type method, in the outputfile related to the costfunction the columns follow this convention:
1st column: number of iteration
2nd column: total cost function
3rd column: surface term of the cost function measuring the mismatch between Neumann and Dirichlet problem
4th column: integral on the beta of the derivative of beta (penalisation term)
For the Lambda-curve plot column 4 has to be plotted against column 3 for different values of lambda. Note, that it is $2=$3+0.5*lambda$4“.

problems/inverse.txt · Last modified: 2013/07/18 13:52 by mschafer
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