Last updated on August 12th 2016.

16. Next Iterations

Once you updated your model it is time to go to the next iteration. Depending on the state of the inversion and your goals you might which to add more events and data. Just use the tools introduced in the previous sections. Please never delete data you used in any of the iterations, otherwise you hurt the reproducibility of your inversion.

You essentially have two options to go from one iteration to the next: Create a new iteration or update from the previous one. In any case, you are responsible for the name of the iteration.

16.1. Create a new iteration from scratch

Here we will create an iteration 2 for the tutorial with the same settings as iteration 1.

$ lasif create_new_iteration 2 40.0 100.0 SES3D_4_1

Using this command will create a new iteration with all the data currently in the project, thus all events and all waveforms it can find. This is also useful if you want to choose a different waveform solver or a different frequency range for the next iteration.

16.2. Deriving from an existing iteration

The other option is to derive a new iteration from an existing iteration. In this case, the solver and preprocessing settings will remain the same, as will the used data. Any data not used for the previous iteration will also not be used for this iteration.

$ lasif create_successive_iteration 1 2

This commando takes an existing iteration 1 and uses it as a template for iteration 2.

16.3. Migrating the misfit windows

Once the windows for the misfit calculation have been determined for an iteration they can usually be used for a couple of iterations before they have to be determined again. The following command will take all windows defined in iteration 1 and transfer them to iteration 2. The synthetics for iteration 2 already need to be available. Depending on the size of the iteration, this might take a while as it also calculates the adjoint sources for each window.

$ lasif migrate_windows 1 2

Please keep in mind that this command will not create windows for data not present in the first iteration.

The finalize_adjoint_sources command can then be used generate the adjoint sources in a format suitable for SES3D to finish the iteration.