نتایج جستجو برای: reverse time migration rtm

تعداد نتایج: 2098134  

2017
Eizo Watanabe Shingo Yamazaki Daisuke Setoguchi Tomohito Sadahiro Yoshihisa Tateishi Tatsuya Suzuki Itsuko Ishii Shigeto Oda

INTRODUCTION Recombinant human soluble thrombomodulin (rTM) is reportedly excreted by the kidneys; therefore, the recommended dose for patients with renal impairment is one-third of the standard dose. The aim of this study was to evaluate whether this reduced dose of rTM achieves effective drug concentrations that are comparable to those of the standard dose in treating sepsis-induced dissemina...

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2013
Michael A H Hedlin Kristoffer T Walker

We discuss the use of reverse time migration (RTM) with dense seismic networks for the detection and location of sources of atmospheric infrasound. Seismometers measure the response of the Earth's surface to infrasound through acoustic-to-seismic coupling. RTM has recently been applied to data from the USArray network to create a catalogue of infrasonic sources in the western US. Specifically, ...

2008
Paul Sava

Multicomponent data are not usually processed with specifically designed procedures, but with procedures analogous to the ones used for single-component data. In isotropic media, the vertical and horizontal components of the data are commonly taken as proxies for the Pand S-wave modes which are imaged independently with acoustic wave equations. This procedure works only if the vertical and hori...

2006
William W. Symes

The optimal checkpointing algorithm (Griewank and Walther, 2000) minimizes the computational complexity of the adjoint state method. Applied to reverse time migration, optimal checkpointing eliminates (or at least drastically reduces) the need for disk i/o, which is quite extensive in more straightforward implementations. This paper describes optimal checkpointing in a form which applies both t...

2008
Paul Sava

Multicomponent data usually are not processed with specifically designed procedures but with procedures analogous to those used for single-component data. In isotropic media, the vertical and horizontal components of the data commonly are taken as proxies for the Pand S-wave modes, which are imaged independently with the acoustic wave equations. This procedure works only if the vertical and hor...

2014
Esteban Díaz Paul Sava

Reverse time migration backscattering contains kinematic information that can be used to constrain velocity models. The backscattering results from the correlation between forward scattered and backscattered wavefields from sharp interfaces, i.e., sediment-salt interfaces. The synchronization between these wavefields depends on the velocity of the sediment section and the correct interpretation...

2014
Yuting Duan

Receiver-side water-column multiples acquired with ocean-bottom seismic sensors can be used for elastic imaging of the subsurface, which can provide additional information relative to more conventional acoustic imaging. In this paper, we generalize the procedures for elastic migration using water-column multiples. We first separate receiver-side water-column multiples from primaries in recorded...

2016
Yuting Duan Paul Sava Antoine Guitton

Least-squares migration (LSM) can produce images with improved resolution and reduced migration artifacts. We propose a method for elastic least-squares reverse time migration (LSRTM) based on different types of imaging condition. Perturbation imaging condition leads to images for squared P and S velocity models; the displacement imaging condition crosscorrelates components of the source and re...

2011
Sheng Xu Yu Zhang Bing Tang

Common-image gathers are an important output of prestack depth migration. They provide information needed for velocity model building and amplitude and phase information for subsurface attribute interpretation. Conventionally, common-image gathers are computed using Kirchhoff migration on commonoffset/azimuth data volumes. When geologic structures are complex and strong contrasts exist in the v...

2015
Junzhe Sun

Attenuation in seismic wave propagation is a common cause for poor illumination of subsurface structures. Attempts to compensate for amplitude loss in seismic images by amplifying the wavefield may boost high-frequency components and create undesirable imaging artifacts. In this paper, rather than amplifying the wavefield directly, we develop a stable compensation operator using smooth division...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید