Method for generating spread spectrum driver signals for a seismic vibrator array using multiple biphase modulation operations in each driver signal chip
AssigneePGS Geophysical AS
InventorStig Rune Lennart Tenghamn
Life of this patent
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Abstract
A method for generating seismic energy for subsurface surveying include operating a first seismic vibrator above an area of the subsurface to be surveyed and operating at least a second seismic vibrator above the area substantially contemporaneously with the operating the first seismic vibrator. The first and the second vibrators each have a different selected frequency response. The first and second vibrators each is operated by a same direct sequence spread spectrum signal, wherein a different number of modulation operations for each logical value in the direct sequence spread spectrum signal is selected for each vibrator.
Claims13
A method for generating seismic energy for subsurface surveying, comprising:
- operating a first seismic vibrator above an area of the subsurface to be surveyed;
- and
- operating at least a second seismic vibrator above the area substantially contemporaneously with the operating the first seismic vibrator, the first seismic vibrator and the at least a second vibrator each having a different selected frequency response range, the first and second vibrators each operated by a same direct sequence spread spectrum driver signal, wherein a different number of modulation operations for each logical value in the direct sequence spread spectrum signal is selected for each vibrator.
A method for subsurface seismic surveying, comprising:
- operating a plurality of seismic vibrators each having a different selected frequency response range above an area of the subsurface to be surveyed;
- and
- detecting seismic signals originating from the plurality of vibrators at each of a plurality of seismic receivers disposed at spaced apart locations above the area;
- wherein each vibrator is operated by a same direct sequence spread spectrum driver signal;
- wherein a different number of modulation operations for each logical value in the driver signal is selected for each vibrator;
- and
- determining seismic energy originating from each of the plurality of vibrators in the detected seismic signals.
Dependencies are inferred from the claim text.