Method and node deployer for seismic surveys

A method for seismic survey by autonomous seismic nodes at a sea floor, comprising:

• attaching the autonomous seismic nodes to a rope with a predefined spacing between the seismic nodes, the autonomous seismic nodes comprising a recorder, a memory for storing seismic signals and a power source and the autonomous seismic nodes are detachably connected to the rope;
• loading the rope with the autonomous seismic nodes into a magazine;
• loading the magazine into a node deployer, wherein the node deployer comprising one or more deflectors for controlling lateral movement of the node deployer during towing, the node deployer comprising one or more flaps to control vertical movement during towing, the node deployer comprising instrumentation to identify obstacles, the node deployer being connected to a vessel at a sea surface by tow cable, and the node deployer is configured to control the rope deploying out of the magazine at a rate of freely or faster than a speed of the node deployer to deploy the autonomous seismic nodes in pre-defined positions and maintaining spacing of the autonomous seismic nodes while preventing dragging the autonomous seismic nodes along the sea floor;
• lowering the node deployer into the sea from the vessel;
• towing the node deployer above the sea floor by the vessel;
• steering the node deployer away from obstacles detected by the instrumentation to identify obstacles;
• deploying the rope with the autonomous seismic nodes from the magazine at the sea floor in pre-defined positions and maintaining spacing of the autonomous seismic nodes while preventing dragging the autonomous seismic nodes along the sea floor;
• collecting seismic data by the autonomous seismic nodes;
• retrieving the rope with the autonomous seismic nodes from the sea floor;
• and
• unloading seismic data from the autonomous seismic nodes.