A constrained-based optimization approach for seismic data recovery problems

Random and structured noise both affect seismic data, hiding the reflections of interest (primaries) that carry meaningful geophysical interpretation. When the structured noise is composed of multiple reflections, its adaptive cancellation is obtained through time-varying filtering, compensating inaccuracies in given approximate templates. The under-determined problem can then be formulated as a convex optimization one, providing estimates of both filters and primaries. Within this framework, the criterion to be minimized mainly consists of two parts: a data fidelity term and hard constraints modeling a priori information. This formulation may avoid, or at least facilitate, some parameter determination tasks, usually difficult to perform in inverse problems. Not only classical constraints, such as sparsity, are considered here, but also constraints expressed through hyperplanes, onto which the projection is easy to compute. The latter constraints lead to improved performance by further constraining the space of geophysically sound solutions.Comment: International Conference on Acoustics, Speech and Signal Processing (ICASSP 2014); Special session "Seismic Signal Processing

Acoustic Detection and Characterization of Marine Sediment with Shallow Seismic Technology in Rambat Waters, Bangka Belitung

High resolution of marine seismic reflection seismic were used to detect the layers of seafloor sediment and to interpret the seismic data geologically. The objectives of this study weres to detect and to characterize the seafloor sediment in the Rambat area, West Bangka, Bangka Belitung. Acquisition data was held on 10-24 August 2012 located between 105.1°00\u2700" - 105.5°00\u2700 " N and 1.7°00\u2700"-1.9° 00\u2700" W. Several methods used to process the data were geometry processing, band pass filter, predictive deconvolution, and Autocoralation Gain Control (AGC) in order to reduce the multiple noise and to ease the data interpretation. Seismic cross section found in Cross Rambat (CRMBT) line 11 exhibited sedimentation process of the sea floor which rocky substrates. The process was assumed to be occurred due to legal and illegal mining activities for long period of time

ACOUSTIC DETECTION AND CHARACTERIZATION OF MARINE SEDIMENT WITH SHALLOW SEISMIC TECHNOLOGY IN RAMBAT WATERS, BANGKA BELITUNG

High resolution of marine seismic reflection seismic were used to detect the layers of seafloor sediment and to interpret the seismic data geologically. The objectives of this study weres to detect and to characterize the seafloor sediment in the Rambat area, West Bangka, Bangka Belitung. Acquisition data was held on 10-24  August  2012 located between 105.1°00'00" - 105.5°00'00 " N and 1.7°00'00"-1.9° 00'00" W. Several methods used to process the data were geometry processing, band pass filter, predictive deconvolution,  and Autocoralation Gain Control (AGC)  in order to reduce the multiple noise and to  ease the data interpretation. Seismic cross section found in Cross Rambat (CRMBT) line 11 exhibited  sedimentation process of the sea floor which rocky substrates. The process was assumed to be occurred due to legal and illegal mining activities for long period of time. Keywords: seismic, acoustic, sediment, band pass filter, deconvolution, nois

Practical solutions for seismic free-surface and internal multiple attenuation based on inversion

Multiple prediction through inversion (MPI) is an effective method for seismic multiple attenuation. The research in this thesis aims to make the MPI method more practical for both free-surface and internal multiple attenuation. For free-surface multiple attenuation, the MPI scheme requires the input data to be dense and regularly sampled, and with one shot at each receiver position. In order to meet these requirements, I use a multilevel B-spline method for seismic data reconstruction. This method can perform regularisation and interpolation on seismic data without any prior-knowledge of models. For free-surface multiple attenuation on marine data, MPI can generate superior results compared to SRME (surface-related multiple attenuation). However, MPI is more computationally expensive due to the large amount of matrix operations involved. The conventional implementation addresses this by approximating the multiple model prediction operator as a pentadiagonal or a tridiagonal matrix. Tackle this problem by solving the full prediction operator using a Graphic Processing Unit (GPU), this accelerates the processing and improve the multiple attenuation results, especially for far-offset traces. As extensions of SRME for internal multiple attenuation, both the CFP (common-focus-point) technique and correlation method have problems. The results can be improved using the MPI method with GPU acceleration. The correlation method is preferred as the initial step for MPI because it can be implemented as a fully data-driven pre-stack domain approach in either forward data space or inverse data space. In all cases, the MPI scheme generates internal multiple models with improved kinematic and dynamic accuracy

50 Years Geophysical Institute Karlsruhe, 1964 to 2014 - Expectations and Surprises

Die Festschrift anlässlich des 50. Geburtstags des Geophysikalischen Instituts in 2014 wurde hauptsächlich von Herrn Dr. Claus Prodehl zusammengestellt. Die einzelnen Beiträge stammen von ehemaligen und aktuellen GPI-Mitarbeitern und Mitarbeiterinnen