Underwater Seismic Positioning via Rigid Body Offset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current marine seismic exploration methods face challenges in accurately determining the position of underwater seismic receivers and sources due to the variability of the sea surface, leading to less than optimal seismic data quality, and existing GPS-based systems are expensive and prone to downtime if a receiver fails.
Innovation Solution
A method that determines the coordinates of a satellite antenna attached to a rigid body on the sea surface, measures orientation parameters to calculate a 3D offset, and applies this shift to underwater acoustic devices, using acoustic ranging and inertial measurement units to achieve sub-meter accuracy in positioning, thereby improving the precision of seismic data acquisition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS-based acoustic positioning systems are used to determine underwater component positions, then positioning capability is provided, but system cost increases and reliability decreases due to expensive equipment and vulnerability to receiver failure
Solution Approach 1:
The patent introduces a rigid body as an intermediary carrier that physically connects the GPS receiver (at sea level) to the underwater acoustic component. This rigid body serves as a mediator that transfers position information from the surface to the underwater component, eliminating the need for expensive underwater GPS receivers while maintaining positioning accuracy through the known rigid body geometry and orientation measurements.
Solution Approach 2:
The patent replaces the complex mechanical/acoustic underwater positioning system with a simplified system based on measuring the orientation parameters (pitch, roll, yaw) of the rigid body. By using orientation sensors on the rigid body rather than complex acoustic ranging systems, the solution reduces equipment cost and complexity while achieving comparable or better positioning precision.
2Measurement precision
If conventional GPS surface positioning is used, then surface position is determined, but underwater component position remains unknown due to sea surface variability
Solution Approach 1:
The patent transitions from two-dimensional surface positioning to three-dimensional underwater component positioning by adding the dimension of the rigid body's orientation and geometry. By measuring pitch, roll, and yaw angles of the rigid body and knowing its fixed geometry, the system calculates the three-dimensional position of the underwater component relative to the GPS receiver, compensating for sea surface variability.
Solution Approach 2:
The patent establishes a fixed geometric relationship between the GPS receiver and the underwater acoustic component through the rigid body before positioning measurements are taken. This preliminary configuration of the rigid body structure allows the system to derive underwater component position from surface GPS data without needing to measure the actual sea surface position at the moment of data acquisition.
3Area of stationary object
If multiple GPS receivers are deployed at strategic points, then surface position coverage is improved, but system complexity and cost increase without providing underwater component position
Solution Approach 1:
The patent makes the rigid body a multi-functional element that simultaneously serves as the GPS receiver platform, the positioning reference, and the connection to the underwater component. This single rigid body structure performs multiple functions that would otherwise require separate systems, reducing overall system complexity while maintaining broad surface coverage capability through the vessel's movement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enhances the accuracy of seismic data acquisition by providing sub-meter precision in determining the relative positions of seismic components, reducing downtime and costs associated with equipment failure, and improving the reliability of marine seismic surveys.
Implementation Method 1
determining coordinates of a first point (from example a satellite antenna) rigidly attached to a rigid body floating on the sea surface
Implementation Method 2
determining on a shipboard computer a distance from the second point fixed to the rigid body to one or more devices that are components of a marine seismic acquisition spread, by comparing transmission times of a signal to recording times of transmitted signals and further multiplying by a signal propagation rate
Data Source
AI summary
A method comprising determining coordinates of a first point rigidly attached to a rigid body floating on the sea surface in a desired coordinate reference frame; measuring orientation parameters of the rigid floating body to determine 3D offset in the coordinate reference frame of the first point to any point on or rigidly attached to the body; applying a 3D coordinate shift from the first point to a second point rigidly attached to the body, thus determining coordinates of the second point in the desired reference frame; determining a distance from the second point to one or more devices that are components of a seismic acquisition spread, by comparing transmission times of a signal to recording times of transmitted signals and multiplying by a signal propagation rate; and determining relative positions of components of the spread to each other and to devices rigidly attached to the rigid body.