The forward and direct inversion of complex gravity and magnetic field of regular 2Dbodies under the condition of undulate topography" consists of four successive papers. The forward problem of complex gravity ...The forward and direct inversion of complex gravity and magnetic field of regular 2Dbodies under the condition of undulate topography" consists of four successive papers. The forward problem of complex gravity and magnetic fields is expounded in the first and the second paper. Mainly using Russian scholars’ method, the author deduced strictly and simply the complex gravity and magnetic field expressions of regular 2Dbodies and their combination bodies in complex field. Compared with the gravity and magnetic field expressions of these bodies in rectangular coordinates system, these expressions of complex fields have very simple forms. In the third and the fourth paper, the direct inversion problem of complex gravity and magnetic fields is expounded, which makes up the core of the serial papers. In these two papers, according to the complex gravity and magnetic field expressions of regular 2Dbodies and their combination bodies, the author first established linear simultaneous equations for solving middle variables in the complex coordinates system by use of his creative method of linearization, then established the highorder complex equation by use of middle variables to be solved out. As for the linear simultaneous equations and the high-order complex equation, the author solved successfully the direct inversion problem of complex gravity and magnetic fields of almost all regular 2Dbodies under the condition of undulate topography (or under the condition that the observation line lies in the arbitrary direction of 2Danomaly sources or is even closed).展开更多
Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by whi...Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by which static correction is completely abandoned before migration and surely the imaging quality is remarkably improved. To obtain some artificial shot gathers, high-order staggered-grid finite-difference （FD） method is adapted to model acoustic wave propagation. Since the shot gathers are always disturbed by regular interferences, the statics still must be applied to supporting the interference elimination by apparent velocity filtering method. Then all the shot gathers should be removed back to their original positions by reverse statics. Finally, they are migrated by pre-stack reverse-time depth migration and imaged. The numerical experiments show that the DPDM can ideally avoid the mistakes caused by statics and increase imaging precision.展开更多
文摘The forward and direct inversion of complex gravity and magnetic field of regular 2Dbodies under the condition of undulate topography" consists of four successive papers. The forward problem of complex gravity and magnetic fields is expounded in the first and the second paper. Mainly using Russian scholars’ method, the author deduced strictly and simply the complex gravity and magnetic field expressions of regular 2Dbodies and their combination bodies in complex field. Compared with the gravity and magnetic field expressions of these bodies in rectangular coordinates system, these expressions of complex fields have very simple forms. In the third and the fourth paper, the direct inversion problem of complex gravity and magnetic fields is expounded, which makes up the core of the serial papers. In these two papers, according to the complex gravity and magnetic field expressions of regular 2Dbodies and their combination bodies, the author first established linear simultaneous equations for solving middle variables in the complex coordinates system by use of his creative method of linearization, then established the highorder complex equation by use of middle variables to be solved out. As for the linear simultaneous equations and the high-order complex equation, the author solved successfully the direct inversion problem of complex gravity and magnetic fields of almost all regular 2Dbodies under the condition of undulate topography (or under the condition that the observation line lies in the arbitrary direction of 2Danomaly sources or is even closed).
文摘Engineering seismic exploration aims at shallow imaging which is confused by statics if the surface is uneven. Direct pre-stack depth migration （DPDM） is based on accurate elevations of sources and receivers, by which static correction is completely abandoned before migration and surely the imaging quality is remarkably improved. To obtain some artificial shot gathers, high-order staggered-grid finite-difference （FD） method is adapted to model acoustic wave propagation. Since the shot gathers are always disturbed by regular interferences, the statics still must be applied to supporting the interference elimination by apparent velocity filtering method. Then all the shot gathers should be removed back to their original positions by reverse statics. Finally, they are migrated by pre-stack reverse-time depth migration and imaged. The numerical experiments show that the DPDM can ideally avoid the mistakes caused by statics and increase imaging precision.
