Steering for coverage in seismic surveys

1. A method for configuring a marine seismic acquisition system, the method comprising:

computing coverage boundaries for a current line in a seismic survey and for an already acquired adjacent line in the seismic survey;

computing cross-line distances between the coverage boundary for the current line and the coverage boundary for the adjacent line based on a set of specifications for the seismic survey;

determining a steering point associated with towed seismic equipment based on the computed cross-line distances; and

generating at least one steering command for a steering element in the marine seismic acquisition system based on the determined steering point,

wherein the method further comprises:

computing a coverage at a common midpoint (CMP) of each offset class for the seismic survey;

determining a cross-line distance for each CMP offset class needed to meet coverage criteria for the seismic survey;

using the determined cross-line distances, select a CMP at a fold limit associated with the seismic survey from each offset class; and

selecting, as the steering point, the CMP associated with one of the offset classes which has the largest cross-line distance.

2. The method of claim 1 , wherein the coverage boundaries are computed using both geographic and geophysical information.

3. The method of claim 2 , wherein the geophysical information includes at least one of offset and azimuth.

4. The method of claim 1 , wherein the largest cross-line distance is determined by:

determining which of the CMPs selected for each offset class has a maximum difference between its cross-line distance and a distance authorized by the set of specifications for the seismic survey.

5. The method of claim 1 , further comprising:

actuating the steering element to steer at least one of a vessel, a source or a receiver in the marine seismic acquisition system based on the steering command.

6. A system for collecting seismic data comprising:

at least one vessel that tows seismic equipment capable of generating and/or receiving seismic waves; and

a processor, associated with a navigation system, which is configured to:

compute coverage boundaries for a current line in a seismic survey and for an already acquired adjacent line in the seismic survey;

compute cross-line distances between the coverage boundary for the current line and the coverage boundary for the adjacent line based on a set of specifications for the seismic survey;

determine a steering point associated with towed seismic equipment based on the computed cross-line distances; and

generate at least one steering command for a steering element in the system based on the determined steering point,

wherein the processor is further configured to:

compute a coverage at a common midpoint (CMP) of each offset class for the seismic survey;

determine a cross-line distance for each CMP offset class needed to meet coverage criteria for the seismic survey;

use the determined cross-line distances to select a CMP at a fold limit associated with the seismic survey from each offset class; and

select, as the steering point, the CMP associated with one of the offset classes which has the largest cross-line distance.

7. The system of claim 6 , wherein the coverage boundaries are computed using both geographic and geophysical information.

8. The system of claim 7 , wherein the geophysical information includes at least one of offset and azimuth.

9. The system of claim 6 , wherein the largest cross-line distance is determined by:

determining which of the CMPs selected for each offset class has a maximum difference between its cross-line distance and a distance authorized by the set of specifications for the seismic survey.

10. The system of claim 6 , further comprising:

an actuator configured to actuate the steering element to steer at least one of a vessel, a source or a receiver in the marine seismic acquisition system based on the steering command.