کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
521471 867769 2010 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nonlinear regularization techniques for seismic tomography
موضوعات مرتبط
مهندسی و علوم پایه مهندسی کامپیوتر نرم افزارهای علوم کامپیوتر
پیش نمایش صفحه اول مقاله
Nonlinear regularization techniques for seismic tomography
چکیده انگلیسی

The effects of several nonlinear regularization techniques are discussed in the framework of 3D seismic tomography. Traditional, linear, ℓ2ℓ2 penalties are compared to so-called sparsity promoting ℓ1ℓ1 and ℓ0ℓ0 penalties, and a total variation penalty. Which of these algorithms is judged optimal depends on the specific requirements of the scientific experiment. If the correct reproduction of model amplitudes is important, classical damping towards a smooth model using an ℓ2ℓ2 norm works almost as well as minimizing the total variation but is much more efficient. If gradients (edges of anomalies) should be resolved with a minimum of distortion, we prefer ℓ1ℓ1 damping of Daubechies-4 wavelet coefficients. It has the additional advantage of yielding a noiseless reconstruction, contrary to simple ℓ2ℓ2 minimization (‘Tikhonov regularization’) which should be avoided. In some of our examples, the ℓ0ℓ0 method produced notable artifacts. In addition we show how nonlinear ℓ1ℓ1 methods for finding sparse models can be competitive in speed with the widely used ℓ2ℓ2 methods, certainly under noisy conditions, so that there is no need to shun ℓ1ℓ1 penalizations.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Computational Physics - Volume 229, Issue 3, 1 February 2010, Pages 890–905
نویسندگان
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