New towed-array shape-estimation scheme for real-time sonar systems

In real-time towed-array systems, performance degradation of array gain occurs when a line array that is not straight is assumed straight in the beamforming process. In this paper, a new method is proposed for array shape estimation. The novelty of this method is that it accounts for the variations...

Full description

Saved in:
Bibliographic Details
Published in:IEEE journal of oceanic engineering 2003-07, Vol.28 (3), p.552-563
Main Authors: Feng Lu, Milios, E., Stergiopoulos, S., Dhanantwari, A.
Format: Article
Language:English
Subjects:
Algorithms
Array signal processing
Arrays
Compasses
Degradation
Distortion
Earth, ocean, space
Equations
Exact sciences and technology
External geophysics
Geophysics. Techniques, methods, instrumentation and models
Linear systems
Marine
Marine optics and underwater sound
Mathematical analysis
Mathematical models
Performance gain
Physics of the oceans
Real time
Real time systems
Sensor systems
Sensors
Shape
Sonar
Studies
Tail
Underwater sound
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In real-time towed-array systems, performance degradation of array gain occurs when a line array that is not straight is assumed straight in the beamforming process. In this paper, a new method is proposed for array shape estimation. The novelty of this method is that it accounts for the variations in the tow ship's speed, which are typical during course alterations. The procedure consists of two steps. First, we solve for the tow-point induced motion in the time domain based on the constraints from the tow-point compass-sensor readings and from a discretized Paidoussis equation. At each time instance, the shape estimate is solved from a linear system of equations. We also show that this solution is equivalent to a previous frequency-domain solution while the new approach is much simpler. In the second step, we use the tail compass-sensor data to adjust the overall array shape. By noting that variations in the ship speed lead to a distortion in the normalized time axis, we first register the predicted tail displacement with the tail sensor readings along the time axis. Then, distortions in the estimated array shape over its length can be compensated accordingly. We also model a slow-changing bias between sensor zeros and remove systematic sensor errors. The effectiveness of the new algorithm is demonstrated with simulations and real sea-trial data.
ISSN:0364-9059
1558-1691
DOI:10.1109/JOE.2003.816694