Low frequency synthetic aperture sonar for detecting and classifying buried objects
conference paper
Sidescan high-frequency (HF) sonar (i.e., with frequencies higher than 100 kHz) is ideally suited for
providing high-resolution images of the seafloor. However, since sound does not penetrate into the
sediment at these frequencies, such systems cannot be used for the detection of buried objects,
such as naval mines, improvised explosive devices (IEDs), and unexploded ordinance (UXO).
Sidescan low-frequency (LF) sonar is a promising technology for the detection of objects buried in
soft seafloor sediment. Acoustic energy is attenuated less by the sediment at lower frequencies and
can therefore penetrate deeper, facilitating the detection of buried objects. Furthermore, a sidelooking
configuration yields a much higher area coverage rate compared to downward-looking
systems (e.g., the BOSS system [1]), thus enabling efficient surveys.
In practice there are two fundamental issues with sidescan LF sonar. The resolution of conventional
sidescan sonar is poor at low frequencies due to the lower directivity of the beams. Moreover, in
addition to the targets of interest, many clutter contacts are also observed, including other buried
objects (e.g., boulders) and geological features below the mud (e.g., sand ripples). Thus, a means
of classification is necessary to distinguish between targets and clutter and to suppress the false
alarms. Synthetic aperture sonar (SAS) processing is essential for attaining adequate
providing high-resolution images of the seafloor. However, since sound does not penetrate into the
sediment at these frequencies, such systems cannot be used for the detection of buried objects,
such as naval mines, improvised explosive devices (IEDs), and unexploded ordinance (UXO).
Sidescan low-frequency (LF) sonar is a promising technology for the detection of objects buried in
soft seafloor sediment. Acoustic energy is attenuated less by the sediment at lower frequencies and
can therefore penetrate deeper, facilitating the detection of buried objects. Furthermore, a sidelooking
configuration yields a much higher area coverage rate compared to downward-looking
systems (e.g., the BOSS system [1]), thus enabling efficient surveys.
In practice there are two fundamental issues with sidescan LF sonar. The resolution of conventional
sidescan sonar is poor at low frequencies due to the lower directivity of the beams. Moreover, in
addition to the targets of interest, many clutter contacts are also observed, including other buried
objects (e.g., boulders) and geological features below the mud (e.g., sand ripples). Thus, a means
of classification is necessary to distinguish between targets and clutter and to suppress the false
alarms. Synthetic aperture sonar (SAS) processing is essential for attaining adequate
Topics
TNO Identifier
462560
Source title
Proceedings of the 11th European Conference on Underwater Acoustics - ECUA 2012, 2-6 July 2012, Edinburgh, UK
Files
To receive the publication files, please send an e-mail request to TNO Repository.