Magnetic sensors for buried minehunting from small unmanned underwater vehicles

Optical identification, which can provide compelling confirmation that a proud sonar contact is a mine, is obviously not possible for fully buried mines. One interesting sensor-fusion concept under consideration to confirm buried sonar contacts is to reacquire the contacts at short range using an unmanned underwater vehicle (UUV) carrying a magnetic sensor and a bottom-looking sonar, such as the Buried Object Scanning Sonar (BOSS) developed by Florida Atlantic University. Two magnetic sensors are currently being developed by the Office of Naval Research (ONR) for buried minehunting. The Quantum Magnetics' Realtime Tracking Gradiometer (RTG) is a multichannel tensor gradiometer being developed using fluxgate technology. An existing RTG prototype has been integrated with an existing BOSS prototype onboard a tow body and underwater tow tests have been conducted over targets to demonstrate the effectiveness of the BOSS/RTG fusion concept. A new miniaturized version of the RTG is being developed for operation onboard relatively small unmanned underwater vehicles (UUVs). The Polatomic Laser Scalar Gradiometer (LSG) is a multichannel scalar magnetic sensor designed to operate on relatively small UUVs. It is based on the electron-spin resonance (ESR) properties of helium-4 gas in accordance with the Zeeman effect, very similar in concept to the US Navy's AN/ASQ-208. The LSG has attained increased sensitivity over the AN/ASQ-81 by the use of a laser in place of incoherent light for optical pumping. In this paper, the sensors and system configurations being pursued are discussed. Relevant tests that have been conducted for individual sensors and sensor combinations and test results are described. Current status of these developments and future plans to test and demonstrate these technologies and concepts are presented.

[1]  G. I. Allen,et al.  Measurement of magnetic noise characteristics on select AUVs with some potential mitigation techniques , 2002, OCEANS '02 MTS/IEEE.

[2]  Steven G. Schock,et al.  Buried object scanning sonar , 2001 .

[3]  J. Bono,et al.  Magnetic sensor operation onboard a UUV: magnetic noise investigation using a total-field gradiometer , 2003, Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492).

[4]  Ted R. Clem,et al.  Superconducting magnetic sensors for mine detection and classification , 1995, Defense, Security, and Sensing.

[5]  S. G. Schock,et al.  Sonar for multi-aspect buried mine imaging , 2002, OCEANS '02 MTS/IEEE.

[6]  T. R. Clem,et al.  Sensor technologies for hunting buried sea mines , 2002, OCEANS '02 MTS/IEEE.

[7]  Robert Matthews,et al.  Mitigation of platform generated magnetic noise impressed on a magnetic sensor mounted in an autonomous underwater vehicle , 2001, MTS/IEEE Oceans 2001. An Ocean Odyssey. Conference Proceedings (IEEE Cat. No.01CH37295).

[8]  J. Bono,et al.  Localization of magnetic dipole targets , 2004, Oceans '04 MTS/IEEE Techno-Ocean '04 (IEEE Cat. No.04CH37600).

[9]  R. E. Slocum,et al.  Polatomic advances in magnetic detection , 2002, OCEANS '02 MTS/IEEE.

[10]  T. R. Clem,et al.  Progress in the development of buried minehunting systems , 2003, Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492).

[11]  Alexander R. Perry,et al.  Development of a man-portable room-temperature gradiometer--phase II: portable and fieldable prototype , 1999, Defense, Security, and Sensing.

[12]  J. Bono,et al.  Magnetic sensor operation onboard an AUV: magnetic noise issues and a linear systems approach to mitigation , 2002, OCEANS '02 MTS/IEEE.

[13]  R. E. Slocum,et al.  Advanced Sensors for Airborne Magnetic Measurements , 2001 .

[14]  T. Clem,et al.  Evaluation of the Polatomic P-2000 laser pumped He-4 magnetometer/gradiometer , 2002, OCEANS '02 MTS/IEEE.

[15]  S. G. Schock,et al.  Buried object scanning sonar for AUVs , 2003, Oceans 2003. Celebrating the Past ... Teaming Toward the Future (IEEE Cat. No.03CH37492).

[16]  Peter V. Czipott,et al.  Initial evaluation and follow-on investigation of the Quantum Magnetics laboratory prototype, room-temperature gradiometer for ordnance location , 1999, Defense, Security, and Sensing.