3.2. Levenberg Marquardt (LM)#

Geophysical Inversion: Damped Least Squares (Levenberg–Marquardt) inversion (DLS)

I use DLS algorithm from Kode Praktikum GP2103 Metode Komputasi versi Python tutorial: Modul 6 - Metode Komputasi 2018 - GP UP.pdf, page 34 and pm6f.py code. This result was showed using sp_dls_inversion.py below.

../../_images/sp_dls_inv_result.png

Initial Model x0: 20 | alpha: 100 (deg) | h: 40 | K: 94500

Real Model x0: 77.070000 | alpha: 5.399525 (rad) | h: 41.810000 | K: 94686.000000

Inversion Model x0: 76.243426 | alpha: 5.415794 (rad) | h: 42.776603 | K: 99102.106072

Error: 0.029529 %

with research paper reference W. Srigutomo, et al, 2016 that is modified sp_dls_inversion_scratch.py below. Jacobian matrix was calculated using derrivatives_in_python.py.