Abstract: Disclosed are methods and systems for towing one or more electromagnetic sensor streamers from deflectors in an additional geophysical sensor streamer spread. An embodiment discloses a marine geophysical survey system, comprising: a survey vessel; an electromagnetic sensor streamer; and a geophysical sensor streamer spread configured to be towed by the survey vessel, wherein the geophysical sensor streamer spread comprises: sensor streamers configured to be laterally spaced apart from one another; and deflectors adapted to spread the sensor streamers substantially transversely in relation to a direction of motion of the survey vessel, wherein the electromagnetic sensor streamer is configured to be towed from at least one of the deflectors.

Abstract: Disclosed are methods and systems for towing one or more electromagnetic sensor streamers from deflectors in an additional geophysical sensor streamer spread. An embodiment discloses a marine geophysical survey system, comprising: a survey vessel; an electromagnetic sensor streamer; and a geophysical sensor streamer spread configured to be towed by the survey vessel, wherein the geophysical sensor streamer spread comprises: sensor streamers configured to be laterally spaced apart from one another; and deflectors adapted to spread the sensor streamers substantially transversely in relation to a direction of motion of the survey vessel, wherein the electromagnetic sensor streamer is configured to be towed from at least one of the deflectors.

Abstract: A system for towing a marine geophysical sensor streamer includes a lead in line extending from a tow vessel. A streamer front end termination is coupled to an end of the lead in line and to a forward end of the sensor streamer. A floatation device is coupled by a line proximate to the front end termination. A winch is disposed on the floatation device to extend and retract the line. A depth sensor is disposed proximate the front end termination. A controller is in signal communication with the winch and the depth sensor so that the forward end of the streamer is maintained at a selected depth in the body of water.

Abstract: A receiver streamer system for marine electromagnetic surveying includes a first streamer, and a second streamer disposed substantially parallel to and spaced apart from the first streamer. A first pair of electrodes is associated with the first streamer and a second pair of electrodes is associated with the second streamer. Each of the first and second pairs of electrodes is functionally associated with a voltage measuring circuit configured to measure voltage along an inline direction. At least one electrode on each of the first and second streamers is configured and associated with a voltage measuring circuit to make voltage measurements in a cross-line direction.

Abstract: A method for reducing motion induced voltage in marine electromagnetic measurements includes measuring an electromagnetic field parameter at at least one position along a sensor cable towed through a body of water. Motion of the sensor cable is measured at at least one position along the cable; Voltage induced in the cable is estimated from the motion measurements. The measured electromagnetic field parameter is corrected using the estimated voltages.

Abstract: A receiver streamer system for marine electromagnetic surveying includes a first streamer, and a second streamer disposed substantially parallel to and spaced apart from the first streamer. A first pair of electrodes is associated with the first streamer and a second pair of electrodes is associated with the second streamer. Each of the first and second pairs of electrodes is functionally associated with a voltage measuring circuit configured to measure voltage along an inline direction. At least one electrode on each of the first and second streamers is configured and associated with a voltage measuring circuit to make voltage measurements in a cross-line direction.

Abstract: A method for reducing motion induced voltage in marine electromagnetic measurements includes measuring an electromagnetic field parameter at least one position along a sensor cable towed through a body of water. Motion of the sensor cable is measured at least one position along the cable; Voltage induced in the cable is estimated from the motion measurements. The measured electromagnetic field parameter is corrected using the estimated voltages.