@article{PAR00011166,
  title = {{G}ravity inversion using wavelet-based compression on parallel hybrid {CPU}/{GPU} systems : application to southwest {G}hana},
  author = {{M}artin, {R}. and {M}onteiller, {V}. and {K}omatitsch, {D}. and {P}errouty, {S}. and {J}essell, {M}ark and {B}onvalot, {S}ylvain and {L}indsay, {M}.},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e solve the 3-{D} gravity inverse problem using a massively parallel voxel (or finite element) implementation on a hybrid multi-{CPU}/multi-{GPU} (graphics processing units/{GPU}s) cluster. {T}his allows us to obtain information on density distributions in heterogeneous media with an efficient computational time. {I}n a new software package called {TOMOFAST}3{D}, the inversion is solved with an iterative least-square or a gradient technique, which minimizes a hybrid {L}-1-/{L}-2-norm-based misfit function. {I}t is drastically accelerated using either {H}aar or fourth-order {D}aubechies wavelet compression operators, which are applied to the sensitivity matrix kernels involved in the misfit minimization. {T}he compression process behaves like a pre-conditioning of the huge linear system to be solved and a reduction of two or three orders of magnitude of the computational time can be obtained for a given number of {CPU} processor cores. {T}he memory storage required is also significantly reduced by a similar factor. {F}inally, we show how this {CPU} parallel inversion code can be accelerated further by a factor between 3.5 and 10 using {GPU} computing. {P}erformance levels are given for an application to {G}hana, and physical information obtained after 3-{D} inversion using a sensitivity matrix with around 5.37 trillion elements is discussed. {U}sing compression the whole inversion process can last from a few minutes to less than an hour for a given number of processor cores instead of tens of hours for a similar number of processor cores when compression is not used.},
  keywords = {{W}avelet transform ; {I}nverse theory ; {N}umerical approximations and analysis ; {S}atellite gravity ; {G}ravity anomalies and {E}arth structure ; {GHANA}},
  booktitle = {},
  journal = {{G}eophysical {J}ournal {I}nternational},
  volume = {195},
  numero = {3},
  pages = {1594--1619},
  ISSN = {0956-540{X}},
  year = {2013},
  DOI = {10.1093/gji/ggt334},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00011166},
}