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PULSE CODING IN SEISMIC PROSPECTING SOSIE AND SEISCODE *
Author(s) -
BARBIER M. G.,
VIALLIX J. R.
Publication year - 1974
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/j.1365-2478.1974.tb00071.x
Subject(s) - computer science , noise (video) , coding (social sciences) , pulse (music) , geology , acoustics , optics , telecommunications , detector , physics , mathematics , statistics , artificial intelligence , image (mathematics)
A bstract The conventional seismic technique is subject to a recording time following each transmission of energy, in which it is forbidden to release any new pulse. The recording time depends on the deepest reflection of interest, and is often 10 seconds or more in actual practice. To each transmission corresponds one record, i.e. a fixed amount of data which cannot be increased in a given time. Pulse coding allows us to go beyond this limit, by transmitting several times during the normal recording time. The procedure gives as many records as there are pulses, but they overlap, each event being repeated every time there is a pulse. It is possible to process the composite record back to its usual appearance with all events in their proper place if the time breaks are accurately known and make up a code such that the unavoidable noise generated by the process be kept, on the final section, below the ambient noise. The processing is quite similar to that of records made from vibrating sources, though faster in practice. The additional information can be devoted to a saving of time and money as the same profile may be recorded in a shorter time; or to an improvement of quality of the section due to a higher order of coverage, a multiplication of the ray paths and a closer sampling of the reflectors. It is also possible to record information in several planes at the same time, and to work out a 3‐dimensional restitution, without loss of production. The process applies to all kinds of sources provided they can be triggered according to the code with sufficient accuracy. Depending on the source and conditions of implementation, the method benefits from other advantages such as better resolution, increased flexibility, and better coupling. Two different names have been given to the process, S osie and S eiscode , which apply to slightly different parameters for the sequence of pulses. S osie is more useful at sea, while the normal scope for S eiscode is onshore. Both names are trademarks for SNPA.