Specifically, the ray tracing or forward modelling has so many methods, such as shortest path ray tracing and pseudobending ray tracing, etc, to accomplish snell law and fermat principle. This article presents a computer library to trace rays in 2. Threedimensional seismic ray tracing in a laterally heterogeneous spherical earth. This project involves both computer science and geo sciences. A wide range of free software and commercial software is available for producing these images. The purpose of seismic modeling is to provide the seismic interpreter with a tool to aid in the interpretation of difficult geological structures. Ray tracing applied to travel time seismic tomography. Introduction three dimensional ray tracing in complex structures can be very cumbersome and slow.
From systematic observations of arrival times, we can deduce useful properties e. Pdf improved applicability of ray tracing in seismic acquisition. Different model representations have been developed for seismic ray tracing. Openraytrace is an optical lens design software that performs ray tracing. Is there any software or codes for modeling the seismic wave. Finally sorted out the snells law lens refraction computation issues.
Program which traces seismic rays through the earth. For complex geology or caving environments, 3d raytracing using a custom built. This is a list of free and opensource software for geophysical data processing and. Seismic ray tracing jyhming lien, george mason university huangliang lai geophysics, roger pearce, sam rodriguez, nancy m. Macray is a general purpose twodimensional seismic raytracer for. Two point ray tracing in particular is difficult because of the need to have the rays converge to specified surface locations or to specified offsets. Seismic time migration is known for its ability to generate wellfocused and interpretable. A number of difficult edge cases are solved by this change. Shows how to shoot seismic rays from surface to the last horizon. Ray trace tomographic velocity analysis of surface seismic.
Velocity models for raytracing are not usually full of random variations, so we would expect that raytracingderived traveltimes and solutions to the eikonal equation would be a closer match at least in the case of simple outgoing wave. Ray tracing in practice shooting method shooting methods of ray tracing are conceptually simple. The intent is that users of the code will provide extra programming for features such as distributed ray tracing, path tracing, photon mapping, radiosity, etc. They are relatively lowlevel and in some cases have their own data formats and involve learning an extensive syntax or metalanguage. Seismic ray article about seismic ray by the free dictionary. Ray tracing migration uses a model of the subsurface to carry out the ray tracing. In geophysics, the term seismic tomography is known for a long time.
In a nutshell it is software used in the seismic exploration business, used to map underground. Ray tracing technique is an important tool not only to forward but also for inverse problems in geophysics, which most of the seismic processing steps depend on. In general, one needs a seismic velocity model to perform seismic ray tracing. Seismic ray tracing is often used to get information about the earths interior. Fundamentals of ray tracing rick aster march 28, 2011 a key observation that we can make about a seismic signal is its arrival time. Review of ray theory applications in modelling and imaging of. The wavefront construction wfc method handles wavefronts instead of individual rays, thereby providing a mechanism to control ray density on the wavefront. One use is for underground surveys near construction called near surface seismic ranging down 50 or hundreds of feet and the other is for very deep p.
Various areas of application have been established and new ones are under development. Many of these applications require a modelling system with flexible, robust and efficient modelling algorithms in the core. Simple being free of charge is not sufficientsee gratis versus libre. Pdf imageray tracing for joint 3d seismic velocity. Hale and cohen 1991 developed software to generate twodimensional computer. These include 2d and 3d seismic ray modeling open ray model, seismic acquisition and processing optimization, psdm simulation simpli approach, reservoir analysis and timetodepth conversion based on ray tracing technology. This method computes traveltimes and raypaths in a 2d velocity structure more rapidly and accurately than other conventional methods. Sim3d is a desktopbased highperformance system simulation software. Recoded much of the basic ray tracing engine to use vectors instead of scalars, with a big improvement in stability and accuracy. Contribute to shuleyu seismic raytracing development by creating an account on github. Free, nice documentation, 2d, geometric optics, fast, nothing new to learn, generally great for quick visualizations, interesting way to transfer macros etc. The general equations derived here are given in terms of the ray slowness vec. For complex geology or caving environments, 3d raytracing using a custombuilt. To verify the robustness of the presented algorithm, we apply our ray tracing method to model real wideangle pwave reflection data collected from an area located at the zagros thrust belt zone in the southwest part of iran.
These would have influenced their tomographic results. Pdf raybased seismic modeling methods can be applied at various stages of the exploration and production. The latest earthquakes on a map with news, lists, and links. Although analytic ray tracing is possible for a few special cases, in general one needs to solve the kinematic ray tracing equation using numerical methods. Finally, this information is compared with field data that has been processed. The latter one is implemented according to the simplex raytracing technique. An efficient sequential algorithm for ray tracing is being developed by the research group of dr. My goal is to be able to plot a ray in a confined space that reflects the ray, but each time it hits a wall the ray decays a little until it vanishes eventually. The technique of ray tracing developed here uses fermats principle to obtain the differential equation of a. The shortest path method for seismic ray tracing in complicated media.
Although both methods have been implemented in the same software. The reader interested in freeware just free of charge software is referred to the list of freeware geophysics software. The simplest one is the 1d model with a vertical sequence of constant material properties separated by plane, horizontal layers. Notice that free and opensource requires that the source code is available. Sambridge research school of earth sciences, australian national university, canberra act 0200, australia 1 introduction 1. Not only is ray trace tomography a useful intellectual exercise as a preliminary analysis of transmission inversion, but in many cases it is a viable technique for addressing serious problems with surface seismic reflection data. Feb 19, 2018 hi everyone, i have been tackling a problem in regards to ray tracing in 2dimensions and havent been able to find anything helpful to help me start the program i want. D ray tracing technique to compute travel times and ray paths. Throughout the last twenty years, 3d seismic ray modelling has developed from a research tool to a more operational tool that has gained growing interest in the petroleum industry. Mesa is a leading edge software package that provides a comprehensive set of tools for.
Improved applicability of ray tracing in seismic acquisition, imaging, and interpretation havar gjoystdal1, einar iversen1, isabelle lecomte1, tina kaschwich1, asmund drottning1, and joachim. This is due to the fact that one of the main problems in seismology the inverse kinematics. Usgs uses github for all new software development, as well as open sourcing older software as time. This article contains a list of best free ray tracing software for windows. Data acquisition is the foundation of the seismic lifecycle. Jan 10, 2018 the exact image you have in your comment comes from paul lutus opticalraytracer program. Ray tracing equations in transversely isotropic media cosmin. Seismic monitor recent earthquakes on a world map and much. Improved performance with nonlinearities is an objective we should seek in other transmission techniques. Seismic modeling, structural modeling, siriri, gibraltar. Ray tracing is a technique that can generate near photorealistic computer images. Dynamic ray tracing and its application in triangulated.
Seismic ray tracing and earth mesh modeling on various parallel architectures. Ray tracing is a technique for rendering threedimensional graphics with very complex light interactions. Software to download institute of geophysics of the cas, v. Seismic ray tracing is a common method for understanding and modeling seismic wave propagation. Seismic ray tracing and wavefront tracking in laterally heterogeneous media n. Reflection seismic processing packages these are fullfeatured reflection seismology processing packages, with support for modeling, imaging, and inversion. Offers fast and simple geologic modeling, ray tracing and target illumination analysis. Raytracing and eikonal solutions for lowfrequency wavefields. Ray tracing is a technique used to generate an image by tracing the path of light as pixels in an image plane and simulating the effects with virtual objects. Threedimensional twopoint ray tracing using paraxial rays. Investors insights events resources careers contact. The software is compatible with either windows or linux.
A number of other velocity functions yield analytic ray tracing solutions, such as the constant gradient of lnv, and the constant gradient of the nth power of slowness 1vn. Ray tracing is being increasingly used in astronomy to simulate realistic images of the sky. Ray tracing is capable of considering all of the light in a given environment termed global illumination. Fast kinematic ray tracing of first and laterarriving global seismic. These are useful to compute travel time, incidence angle, and ray parameter. Unlike conventional simulations, ray tracing does not use the expected or calculated psf of a telescope and instead traces journey of each photon from entering the upper atmosphere to the detector. As seismic interpretation is usually carried out on migrated data, it means that the. The following projects have seen very little activity for more than a year. It has its applications in a number of areas in geosciences including oil exploration and quake fault analysis. Norsar has developed a number of unique software products. Fundamentals of ray tracing new mexico tech earth and. Usgs uses github for all new software development, as well as open. What free software is out there for visualizing optic ray. Fitpacksoftware package for curve and surface fitting employing splines under tension.
Summary we discuss a simple, compact approach to deriving ray tracing equations in transversely isotropic media. We present in this paper the design of a software program imple menting a fast seismic ray tracing in an earth. Ray tracing allows set and lighting designers, actors, and directors to develop and visualize complex lighting setups months before a production ever opens. The lti method is formulated for a 2d cell model, and calculations of traveltimes and raypaths are carried out only on cell. Lithospheric structure and its relationship to seismic and. Image ray tracing for joint 3d seismic velocity estimation and timetodepth conversion. Hypodd is a fortran computer program package for relocating earthquakes with. From this result a valid seismic model is imported to norsar 3d for making the seismic modeling, using ray tracing to get synthetic data.
Sep 04, 2011 seismic ray tracing using evolutionary programming. Seismic ray tracing and wavefront tracking in laterally. Pdf threedimensional seismic ray tracing in a laterally. It consists in determining the velocity structure at a known time path of the refracted waves from source to receiver. However, implementing ray tracing codes can be very time consuming. Considerable attention is devoted to ray tracing and dynamic ray tracing of s waves in heterogeneous anisotropic media, to the coupling ray theory for s waves in such media, to the summation of gaussian beams and packets, and to the selection of models suitable for ray. We will skip most of the theory behind ray tracing, focusing instead on a general overview of the technique from an implementationoriented perspective. Pdf seismic raytracing and earth mesh modeling on various. All the listed software use ray tracing algorithms to create a lifelike rendered 3d scenes or object images. In raypath modeling, ray tracing is carried out for models of multilayered folded structures so as to generate ray diagrams and synthetic time sections. Macray is a general purpose twodimensional seismic raytracer for macintosh. We have verified our methods traveltimes and amplitudes against the norsar ray tracing software. A new ray tracing method called linear traveltime interpolation lti is proposed.923 1433 1394 467 1006 687 1080 1027 409 141 19 1063 232 643 1122 1016 751 499 148 549 1228 1335 1028 992 1143 515 316 812 202 282 1207 280 1516 115 1321 89 1135 580 472 1162 589 663 1014