| 摘要 |
A marine seismic surveying apparatus comprises source arrays 11 and streamers 34 towed laterally outside the source arrays. The source arrays 11 are connected to a towing vessel 12 by source tow cables 35. The streamers 34 are connected to the vessel 12 by streamer tow cables. Each streamer has a deflector 37 which deflects the streamer laterally. Each source array 11 also has a deflector 15. A separation cable 50 connects the outermost source tow cable to the innermost streamer tow cable. The position of the source arrays is thus controlled by a combination of the source deflectors 37 and the streamer deflectors 15. The arrangement allows a nominal lateral position of the source arrays to be achieved using the streamer deflector 37 and the separation cable 50, with the source deflectors 15 correcting for any deviations in the lateral position. Using this arrangement allows the source deflectors 15 to be smaller and less expensive. In an alternative arrangement with no streamers, the deflectors 37 may be towed on dedicated deflector tow member (figures 6,7 and 8). |
