Shot-gather time migration of planar reflectors without velocity model
Standard migration techniques require a velocity model. A new and fast prestack time migration method is presented that does not require a velocity model as an input. The only input is a shot gather, unlike other velocity-independent migrations that also require input of data in other gathers. The o...
| Main Author: | |
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| Format: | Journal Article |
| Published: |
Society of Exploration Geophysicists
2011
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| Online Access: | http://hdl.handle.net/20.500.11937/17241 |
| _version_ | 1848749411901898752 |
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| author | Bona, Andrej |
| author_facet | Bona, Andrej |
| author_sort | Bona, Andrej |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Standard migration techniques require a velocity model. A new and fast prestack time migration method is presented that does not require a velocity model as an input. The only input is a shot gather, unlike other velocity-independent migrations that also require input of data in other gathers. The output of the presented migration is a time-migrated image and the migration velocity model. The method uses the first and second derivatives of the traveltimes with respect to the location of the receiver. These attributes are estimated by computing the gradient of the amplitude in a shot gather. The assumptions of the approach are a laterally slowly changing velocity and reflectors with small curvatures; the dip of the reflector can be arbitrary. The migration velocity corresponds to the root mean square (rms) velocity for laterally homogeneous media for near offsets. The migration expressions for 2D and 3D cases are derived from a simple geometrical construction considering the image of the source. The strengths and weaknesses of the methods are demonstrated on synthetic data. At last, the applicability of the method is discussed by interpreting the migration velocity in terms of the Taylor expansion of the traveltime around the zero offset. |
| first_indexed | 2025-11-14T07:20:31Z |
| format | Journal Article |
| id | curtin-20.500.11937-17241 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:20:31Z |
| publishDate | 2011 |
| publisher | Society of Exploration Geophysicists |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-172412018-09-07T01:26:57Z Shot-gather time migration of planar reflectors without velocity model Bona, Andrej Standard migration techniques require a velocity model. A new and fast prestack time migration method is presented that does not require a velocity model as an input. The only input is a shot gather, unlike other velocity-independent migrations that also require input of data in other gathers. The output of the presented migration is a time-migrated image and the migration velocity model. The method uses the first and second derivatives of the traveltimes with respect to the location of the receiver. These attributes are estimated by computing the gradient of the amplitude in a shot gather. The assumptions of the approach are a laterally slowly changing velocity and reflectors with small curvatures; the dip of the reflector can be arbitrary. The migration velocity corresponds to the root mean square (rms) velocity for laterally homogeneous media for near offsets. The migration expressions for 2D and 3D cases are derived from a simple geometrical construction considering the image of the source. The strengths and weaknesses of the methods are demonstrated on synthetic data. At last, the applicability of the method is discussed by interpreting the migration velocity in terms of the Taylor expansion of the traveltime around the zero offset. 2011 Journal Article http://hdl.handle.net/20.500.11937/17241 10.1190/1.3549641 Society of Exploration Geophysicists fulltext |
| spellingShingle | Bona, Andrej Shot-gather time migration of planar reflectors without velocity model |
| title | Shot-gather time migration of planar reflectors without velocity model |
| title_full | Shot-gather time migration of planar reflectors without velocity model |
| title_fullStr | Shot-gather time migration of planar reflectors without velocity model |
| title_full_unstemmed | Shot-gather time migration of planar reflectors without velocity model |
| title_short | Shot-gather time migration of planar reflectors without velocity model |
| title_sort | shot-gather time migration of planar reflectors without velocity model |
| url | http://hdl.handle.net/20.500.11937/17241 |