Abstract: Signals of pressure sensors and particle motion sensors located in marine seismic streamers are combined to generate a seismic wavefield. At least a part of the particle motion sensor signal is calculated from a recorded pressure signal and the calculated at least a part of the particle motion sensor signal is used to generate a particle motion sensor signal in which noise is substantially attenuated in at least a lower frequency range thereof. The pressure sensor data and the noise attenuated particle motion sensor signal can then be combined to calculate up- and down-going wavefields.

Abstract: A method for characterizing function of an air gun includes measuring, with respect to time, a parameter related to pressure in a charge chamber portion of the air gun. The measurements with respect to time are used to characterize the function of the air gun.

Abstract: Signals of pressure sensors and particle motion sensors located in marine seismic streamers are combined to generate a seismic wavefield. At least a part of the particle motion sensor signal is calculated from a recorded pressure signal and the calculated at least a part of the particle motion sensor signal is used to generate a particle motion sensor signal in which noise is substantially attenuated in at least a lower frequency range thereof. The pressure sensor data and the noise attenuated particle motion sensor signal can then be combined to calculate up- and down-going wavefields.

Abstract: Signals of pressure sensors and particle motion sensors located in marine seismic streamers are combined to generate pressure sensor data and particle motion data with substantially the same broad bandwidth. The noisy low frequency part of the motion signals are calculated from the recorded pressure signals and merged with the non-noisy motion signals. The two broad bandwidth data sets can then be combined to calculate the full up- and down-going wavefields.

Abstract: A method for seismic surveying is disclosed which includes towing a first seismic energy source and at least one seismic sensor system. A second seismic energy source is towed at a selected distance from the first source. The first seismic energy source and the second seismic energy source are actuated in a plurality of firing sequences. Each of the firing sequences includes firing of the first source, waiting a selected time firing the second source and recording signals generated by the seismic sensor system. The selected time between firing the first source and the second source is varied between successive ones of the firing sequences. The firing times of the first and second source are indexed so as to enable separate identification of seismic events originating from the first source and seismic events originating from the second source in detected seismic signals.

Abstract: A method is disclosed for marine seismic surveying in which a seismic signal is detected in a body of water with a motion sensor and a pressure sensor positioned at a location proximate the bottom of the body of water. Seismic signals are detected with pressure sensors positioned in one or more streamer cables being towed in the body of water near the location proximate the bottom of the water at which a motion sensor and a pressure sensor are positioned. The signals detected by the motion sensor and pressure sensor positioned proximate the bottom of the body of water are used for calibrating the seismic signals detected with the pressure sensors positioned in the streamer cables.

Abstract: A method is disclosed for separating energy resulting from actuating at least two different seismic energy sources from seismic signals. The sources are actuated to provide a variable time delay between successive actuations of a first one and a second one of the sources. The method includes sorting the seismic signals such that events therein resulting from actuations of the first source are substantially coherent in all spatial directions, coherency filtering the first source coherency sorted signals, sorting the seismic signals such that events therein resulting from actuations of the second source are substantially coherent in all spatial directions, and coherency filtering the second source coherency sorted signals.

Abstract: A method is disclosed for marine seismic surveying in which a seismic signal is detected in a body of water with a motion sensor and a pressure sensor positioned at a location proximate the bottom of the body of water. Seismic signals are detected with pressure sensors positioned in one or more streamer cables being towed in the body of water near the location proximate the bottom of the water at which a motion sensor and a pressure sensor are positioned. The signals detected by the motion sensor and pressure sensor positioned proximate the bottom of the body of water are used for calibrating the seismic signals detected with the pressure sensors positioned in the streamer cables.

Abstract: A method is disclosed for marine seismic surveying in which upgoing and downgoing components of a seismic wavefield at a seafloor location, and the seismic wavefield at a seismic streamer location substantially above the seafloor location are determined. The upgoing and downgoing seafloor components and the streamer seismic wavefield are used to determine a separation operator. The separation operator when applied to the streamer seismic wavefield provides an estimate of at least one of an upgoing wavefield component and a downgoing wavefield component of the determined seismic wavefield for the streamer location.

Abstract: A method and system are provided for use in marine seismic data surveys to increase fold and offset without increasing streamer length or drag on the streamer boat. Generally the method comprises the use of a second source boat positioned in the steamer path and firing the second source at a time before the recording of information from the first source is finished. By positioning the second source about one streamer length in front of the closest hydrophone, the fold is increased by two for the same length streamer.