{"id":242,"date":"2012-03-28T17:40:43","date_gmt":"2012-03-28T13:40:43","guid":{"rendered":"https:\/\/www.zond-geo.co\/english\/?page_id=242"},"modified":"2018-10-28T20:57:52","modified_gmt":"2018-10-28T16:57:52","slug":"zondst3d","status":"publish","type":"page","link":"https:\/\/www.zond-geo.co\/english\/zond-software\/seismic-tomography\/zondst3d\/","title":{"rendered":"ZondST3D"},"content":{"rendered":" \r\n

ZondST3d<\/strong>\u00a0is designed \u00a0for three-dimensional interpretation of seismic tomography\u00a0data on refracted waves (land, cross-borehole and water variants).<\/p>\r\n

In geophysics,\u00a0the term\u00a0seismic tomography\u00a0is known\u00a0for a long time.\u00a0This is due to\u00a0the fact that one\u00a0of the main problems in\u00a0seismology\u00a0–\u00a0the inverse\u00a0kinematics.\u00a0It consists in determining the\u00a0velocity structure at\u00a0a known\u00a0time\u00a0path of the refracted waves\u00a0from \u00a0source to receiver. \u00a0The most popular\u00a0in engineering\u00a0geophysics\u00a0was\u00a0crosshole Seismotomography.\u00a0This direction is used\u00a0for detailed\u00a0studies of \u00a0rocks\u00a0velocity structure \u00a0in the interborehole space.<\/p>\r\nThe technique of three-dimensional seismotomography means special survey with using of great number of sources and receivers positions. Sometimes number of trace is \u00a0reach thousand and tens thousand. But in many cases for three-dimensional interpretation it is enough to use the results of a two-dimensional seismotomography observed on several parallel lines.\r\n

ZondST3d<\/strong>\u00a0<\/strong>represents ready solution for seismic tomography, and solves wide range of problems from mathematical modeling and quality control to field data processing and interpretation. Convenient interface and variety of data visualization features allow to solve wide range of geological problems with maximum effectiveness.<\/p>\r\n

The software consists of two basic modules. One for the first times picking on the seismograms. The second is used for solving forward and inverse problems of seismic tomography<\/a>.<\/p>\r\n

For the seismograms processing developed a special interface designed to simplify and automate the process of first arrivals picking. Special attention is paid to variety ways of data visualization and simple access to frequently used functions.<\/p>\r\n

\"First<\/a><\/p>\r\n

Solution of forward problem basis on special ray tracing algorithm of graph theory (Shortest path\u2019s method). This algorithm is characterized by a high-speed calculations, and controlled accuracy.<\/p>\r\n

\u00a0ZondST3d<\/strong>\u00a0uses simple and clear data format which allows easily combining various systems of observation, including different variants of the topography setting up and other additional information.<\/p>\r\n

Some variants of three-dimensional model display in the form of various sections and isosurfaces are realized in the program.<\/p>\r\n

Important stage which prevents field measurement is mathematical modeling of velocity structure of work site. Modeling gives a chance to estimate the level of reflected waves first times and to make a choice of optimum parameters of the observation system for decision of formulated geological problem.\u00a0ZondSt3d<\/strong>\u00a0has great range of tools for mathematical modeling and analysis of first times field.<\/p>\r\n

\"Forward<\/a><\/p>\r\n

\u00a0As the general task of the program is inversion of velocity parameters, some variants of inverse problem decision are realized in\u00a0ZondST3d<\/strong>, basic of them are: smoothing inversion \u2013 to get smooth model and focusing \u2014 to get \u00a0piece-smoothed model of velocities with depth. While program was designed special consideration given to a priori data accounting. Because of equivalence of inverse geophysical problems, quality of the obtained results strongly depends on the amount of a priori data\u00a0used. In\u00a0ZondST3d<\/strong>\u00a0there is possibility of weights setting for measurements, fixing and limits making of changing features of different cells, using of a priori model as reference \u00a0in inversion. The robust schemas of noise estimation\u00a0are realized in the software. There is also possibility to import and display results of measurements by other methods and cross-boreholes data that improved quality of results.<\/p>\r\n

\"Result<\/a><\/p>\r\n

Basic features:<\/p>\r\n\r\n