Ladar-Acoustic Fused Sensor for Area Denial Application

The Journal of the Acoustical Society of America, 2003

An acoustic-to-seismic system to detect buried antipersonnel mines exploits airborne acoustic waves penetrating the surface of the ground. Acoustic waves radiating from a sound source above the ground excite Biot type I and II compressional waves in the porous soil. The type I wave and type II waves refract toward the normal and cause air and soil particle motion. If a landmine is buried below the surface of the insonified area, these waves are scattered or reflected by the target, resulting in distinct changes to the acoustically coupled ground motion. A scanning laser Doppler vibrometer measures the motion of the ground surface. In the past, this technique has been employed with remarkable success in locating antitank mines during blind field tests ͓Sabatier and Xiang, IEEE Trans. Geosci. Remote Sens. 39, 1146-1154 ͑2001͔͒. The humanitarian demining mission requires an ability to locate antipersonnel mines, requiring a surmounting of additional challenges due to a plethora of shapes and smaller sizes. This paper describes an experimental study on the methods used to locate antipersonnel landmines in recent field measurements.

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Detection and Remediation Technologies for Mines and Minelike Targets VIII, 2003

Acoustic landmine detection (ALD) is a technique for the detection of buried landmines including non-metal mines. An important issue in ALD is the acoustic excitation of the soil. Laser excitation is promising for complete standoff detection using lasers for excitation and monitoring. Acoustic excitation is a more common technique that gives good results but requires an acoustic source close to the measured area. In a field test in 2002 both techniques were compared side by side. A number of buried landmines were measured using both types of excitation. Various types of landmines were used, both anti-tank and anti-personnel, which were buried at various depths in different soil types with varying humidity. Two Laser Doppler Vibrometer (LDV) systems of two different wavelengths for the different approaches were used, one based on a He-Ne laser at 0.633 µm with acoustic excitation and one on an erbium fiber laser at 1.54 µm in the case of laser excitation. The acoustic excitation gives a good contrast between the buried mine and the surrounding soil at certain frequencies. Laser excitation gives a pulse response that is more difficult to interpret but is potentially a faster technique. In both cases buried mines could be detected.

Progress in Electromagnetics Research C, 2009

The Laser Doppler Vibrometer (LDV)-based Acoustic to Seismic (A/S) landmine detection system is one of the reliable and powerful landmine detection systems. The interpretation of the LDVbased A/S data is performed off-line, manually, depending heavily on the skills, experience, alertness and consistency of a trained operator. This takes a long time. The manually obtained results suffer from errors, particularly when dealing with large volumes of data. This paper proposes some techniques for the automatic detection of objects from the acoustic images which are obtained from the LDV-based A/S landmine detection system. These techniques are based on Corresponding author: F. E. Abd El-Samie (fathi [email protected]).

The focus of this survey paper is to update the advances in the use of acoustic sensors in the contemporary battlefield since 2005. The template for this investigation is a comprehensive paper presented on this subject by Kaushik, Nance, and Ahuja at the 26 th AIAA Aeroacoustics Conferernce in Monterey, California. [1]. Recent engineering advances in nanotechnology, digital signal processing, cybernetics, wireless communications and long-range weapons manufacturing have compelled the armed forces towards more coordinated battlespace operations which deploy autonomous and manned systems equipped with acoustic sensors. This unified battlespace suffused with sensory technology requires an implementation strategy where command decisions are made in real time. Indeed the modern battlefield is a mechanized and digitized environment of rapid information processing and deeply-penetrating surveillance with increased weapons accuracy and target designations. Updates to the improved acoustic sensorybased capabilities of military equipment and systems for ground, aerial, and naval combat that improve battlespace survival will be the central investigation theme , as well as cutting-edge research that has the potential for advancing the acoustic technology used in future conflict scenarios.

J Acoust Soc Amer, 2001

The most commonly used devices for land mine detection are metal detectors that work by measuring the disturbance of an emitted electromagnetic field caused by the presence of metallic objects in the ground. For ferromagnetic objects, magnetometers are employed. These sensors measure the disturbance of the earth's natural electromagnetic field. Neither of these types of detectors can differentiate a mine from metallic debris; this leads to up to 1000 false alarms for each real mine. In addition, most modern antipersonnel mines are made out of plastic or wood with very few metal parts in them, so the metal detectors cannot detect them. Newer methods conceived to detect mines involve ground-penetrating radar, infrared imaging, X-ray backscattering, thermal neutron activation, and some others. Most of these methods rely on imaging and very often cannot differentiate a mine from rocks and other debris. The drawbacks of the other non-imaging techniques, such as thermal neutron activation, apart from system complexity, are the limited depth of penetration and the potential environmental and health danger. Acoustic methods of detecting mines were always a primary approach for underwater mine detection. However, earlier attempts to use acoustic energy for land mine detection were not successful due to a number of deficiencies. One method, House and Pape [1], identifies a buried object by viewing the images of the acoustic energy reflected from the soil and, therefore, is unable to differentiate a mine from debris with similar acoustic reflectivity. Other methods, Rogers and Don [2] and Caulfield [3], are based on the

Journal of The Acoustical Society of America, 2002

142nd ASA Meeting, Fort Lauderdale, FL The most commonly used devices for land mine detection are metal detectors that work by measuring the disturbance of an emitted electromagnetic field caused by the presence of metallic objects in the ground.

IEEE Transactions on Geoscience and Remote Sensing, 2001

Chemical and Biological Sensing VI, 2005

The Army is currently developing acoustic sensor systems that will provide extended range surveillance, detection, and identification for force protection and tactical security. A network of such sensors remotely deployed in conjunction with a central processing node (or gateway) will provide early warning and assessment of enemy threats, near real-time situational awareness to commanders, and may reduce potential hazards to the soldier. In contrast, the current detection of chemical/biological (CB) agents expelled into a battlefield environment is limited to the response of chemical sensors that must be located within close proximity to the CB agent. Since chemical sensors detect hazardous agents through contact, the sensor range to an airburst is the key-limiting factor in identifying a potential CB weapon attack. The associated sensor reporting latencies must be minimized to give sufficient preparation time to field commanders, who must assess if an attack is about to occur, has occurred, or if occurred, the type of agent that soldiers might be exposed to. The long-range propagation of acoustic blast waves from heavy artillery blasts, which are typical in a battlefield environment, introduces a feature for using acoustics and other sensor suite technologies for the early detection and identification of CB threats. Employing disparate sensor technologies implies that warning of a potential CB attack can be provided to the solider more rapidly and from a safer distance when compared to current conventional methods. Distinct characteristics arise within the different airburst signatures because High Explosive (HE) warheads emphasize concussive and shrapnel effects, while chemical/biological warheads are designed to disperse their contents over immense areas, therefore utilizing a slower burning, less intensive explosion to mix and distribute their contents. Highly reliable discrimination (100%) has been demonstrated at the Portable Area Warning Surveillance System (PAWSS) Limited Objective Experiment (LOE) conducted by Joint Project Manager for Nuclear Biological Contamination Avoidance (JPM NBC CA) and a matrixed team from Edgewood Chemical and Biological Center (ECBC) at ranges exceeding 3km. The details of the field-test experiment and real-time implementation/integration of the standalone acoustic sensor system are discussed herein.