Explorer 2 was also equipped with a wire grid array and an acoustic detector for the purpose of micrometeorite detection.

But the police in Newport News, Va., began using the acoustic detectors two weeks ago and said they were pleased with the results.

Acoustic survey in fishing is one of the research methods that can detect the abundance of target species using acoustic detectors.

Hence survey vessel with acoustic detector emits sound waves to estimate the density of plankton and fish shoal.

Glass break acoustic detectors are mounted in close proximity to the glass panes and listen for sound frequencies associated with glass breaking.

Acoustic detector (crystal transducer and solid-state amplifier) to detect micrometeorite (cosmic dust) impacts.

The typical acoustic detector is an ultrasound transducer, which is commonly made of a piezo-electric material that converts detected pressure to an electrical signal.

Higher Pitch, More Detail In principle, the acoustic detector will find an object made of any material other than the soil in which it is buried.

CWF uses two AnaBat acoustic detectors to aid in bat research across the state of New Jersey.

The payload consisted of a cosmic ray counter (a Geiger-Müller tube), and a micrometeorite detector (a wire grid array and acoustic detector).

In general, high-frequency sound does not reach as far under water as does low-frequency sound, so a larger number of propeller blades may help defeat an enemy's acoustic detectors.

They include digital multi-mode radar, electronic support measures, electro-optics detectors (infra-red and visual), magnetic anomaly detectors, identification friend or foe systems, and acoustic detectors.

Scanning for Many Objects Acoustic detectors could also prove useful in locating underground pipes made of plastic, concrete conduits, archeological relics and other non-metallic objects, scientists say.

But starting next week, members of the East Orange Police Department will be able to "hear" the gunshots themselves through a network of high-tech acoustic detectors placed on utility poles and lampposts throughout the city.

According to the Pentagon survey, American engineers are using these powerful machines to design stealth aircraft, infrared trackers to detect incoming missiles, acoustic detectors for use in shallow water, airborne lasers and designs for rocket motors.

Mr. Duval says the center was designed to accommodate an ever-evolving, "intelligent" transportation system, which uses sensors and acoustic detectors to gauge speed and traffic volume; workers can also see accidents on cameras situated at high-volume sites.

When the cameras and acoustic detectors are fully integrated, Mr. Cordero said, they will automatically train on the location of gunshots detected by the acoustic sensors and record any action as officers are dispatched to the scene.

The United States has argued in Geneva for the right to use advanced satellite and other technologies to detect possible treaty violations and demand on-site inspections, in addition to monitoring done by an internationally supervised sensing system of seismic and acoustic detectors.

Any thermoacoustic imaging device requires a source of electromagnetic radiation, be it a laser or a microwave antenna, to deliver energy to the anatomy being studied, and one or more acoustic detectors coupled acoustically to the outside surface of the anatomy, as is illustrated in Fig. 4.