Synthetic tests: investigations of the robustness of unconstrained multiple level set inversions

In this document I show a few synthetic examples using the method of: 

Jérémie Giraud, Mark Lindsay, and Mark Jessell, (2021), "Generalization of level-set inversion to an arbitrary number of geologic units in a regularized least-squares framework," GEOPHYSICS 86: R623-R637, https://library.seg.org/doi/full/10.1190/geo2020-0263.1

to furhter test the robustness of level set inversion to noise and errors in the starting model.