Short Note Enhanced prestack noise removal
نویسنده
چکیده
In a previous paper, Abma and Claerbout(1994), presented a technique for separating signal and noise. This technique was fairly expensive since it used an inversion routine that required many iterations to get a reasonable result. Generally the process worked well, but occasionally the traces that contained high amplitude noise showed weak signal on the output. The cause of both the high cost and erratic results can be attributed to the difficulty the inversion routine had in predicting noise. With spiky noise, the inversion was unlikely to reconstruct the noise accurately, since noise is generally broadband and will not be easily reconstructed from the response of a filter that has a bandlimited response. In this paper, I improve the results of the inversion by initializing the noise estimate with the result of a lateral prediction filter. This initialization is similar to that used in Abma(1995) except that the process is applied to prestack data and the inversion is unchanged from Abma and Claerbout(1994). This initialization improves the results and reduces the cost of the process. I show comparisons of the results of using the inversion with the initial noise estimate being zero as in Abma and Claerbout(1994) and then with the initial noise estimate being the result of a lateral prediction filter on both synthetic and real data.
منابع مشابه
Short Note Prestack time imaging operator for 2-D and 3-D pegleg multiples over nonflat geology
My Least-squares Joint Imaging of Multiples and Primaries (LSJIMP) algorithm (Brown, 2003b) separates pegleg multiples and primaries. LSJIMP computes separate images of the peglegs and primaries, and then uses the mutual consistency of the images to discriminate against unwanted noise types in each image. The images must be consistent in two respects: kinematics and amplitudes. A companion pape...
متن کاملShort Note Traveltime computation with the linearized eikonal equation
Traveltime computation is an important part of seismic imaging algorithms. Conventional implementations of Kirchhoff migration require precomputing traveltime tables or include traveltime calculation in the innermost computational loop . The cost of traveltime computations is especially noticeable in the case of 3-D prestack imaging where the input data size increases the level of nesting in co...
متن کاملShort Note Common-azimuth migration and Kirchhoff migration for 3-D prestack imaging: A comparison on North Sea data
Common-azimuth migration (CAM) is a 3-D prestack depth migration technique based on the wave equation (Biondi and Palacharla, 1996). It exploits the intrinsic narrow-azimuth nature of marine data to reduce its dimensionality and thus manages to cut the computational cost of 3-D imaging significantly enough to compete with Kirchhoff methods. Based on a recursive extrapolation of the recorded wav...
متن کاملShort Note Comparing Kirchhoff with wave equation migration in a hydrate region
Prestack migration is necessary before AVO analysis. Most of the present migration algorithms not only try to focus the reflections on the subsurface but also strive to preserve the amplitude for subsequent amplitude studies. A migration/inversion method developed by Lumley (1993) estimates the angle dependent reflectivity at each subsurface point by using least-squares Kirchhoff migration foll...
متن کاملHeavy Metal Removal from Water and Wastewater Using Raw and Modified Diatomite (TECHNICAL NOTE)
heavy metal removal from water and wastewater was investigated by using raw and modified diatomite from Iranian mines. Modification of diatomite was done by impregnating the diatomite surface with 0.35 g of manganese oxide in one gram of diatomite. This modified diatomite was named Mn-Diatomite. The surface area measurements for Mn-diatomite showed a 2.2 fold increase, hence higher removal capa...
متن کامل