A prototype through-the-wall surveillance system is being developed for use by law enforcement personnel that utilizes high power ultrasonic transducers to detect and locate stationary or moving people inside either metallic or non-metallic walled enclosures. Details of the prototype design will be presented together with recent data and analyses. The sensor is being designed as a field-portable unit with a real-time display of the location, in range and azimuth, of each detected individual. Applications of this technology include detecting and locating unconscious, sleeping, hiding, tightly bound or otherwise stationary people, as well as moving people, inside an enclosed area. The sensor should also prove useful in border patrol applications for inspecting vehicles and shipping containers at points of entry.
A handheld, battery-operated prototype of a concealed weapon detector (CWD) has been built and tested. Designed to detect both metallic and non-metallic weapons, the sensor utilizes focused ultrasound (40 kHz frequency) to remotely detect concealed objects from beyond arm's length out to a range of about 25 feet (8 meters). Applications include weapon detection in prison settings, by officers in the field for stand-off frisking of suspects, and as supplemental security at courthouse entrances and other monitored portals. The detector emits an adjustable, audible alarm (with provision for an earphone jack) as well as a visible light-bar indicator when an object has been detected. An aiming light, with momentary switch, allows the user to accurately determine the location of the concealed object. A presentation of the detector's capabilities and limitations will be presented along with probability of detection (PD) data obtained using the latest prototype version.
A handheld, battery-operated prototype of a concealed weapon detector has been built and tested. Designed to detect both metallic and non-metallic weapons, the sensor utilizes focused ultrasound (40 kHz frequency) to remotely detect concealed objects from beyond arm's length out to a range of about 12 feet (4 meters). The detector can be used in prison settings, by officers in the field to allow for stand-off frisking of suspects, and to supplement security at courthouse entrances and other monitored portals. The detector emits an audible alarm (with provision for an earphone jack) as well as a visible light-bar indicator when an object is detected. A high intensity aiming light, with momentary switch, allows the user to accurately determine the location of the concealed object. Current efforts are aimed at increasing the probability of detection, reducing the false-alarm rate, and extending the range of detectability out to 20 feet. Plans for accomplishing these tasks will be presented together with data showing the effective range and probability of detection for the present system.
KEYWORDS: Sensors, Antennas, Signal processing, Standards development, Computing systems, Receivers, Signal detection, Data communications, Commercial off the shelf technology, Network security
Recent advances in electronic miniaturization have facilitated the design and development of a deployable, stand-alone sensor for battlefield RF (radio frequency) MASINT (measurement and signature intelligence). Recent results of a Phase I effort to assess battlefield RF signatures and compare sensor sensitivity, size, and number for optimal coverage will be presented. An RF sensor suite is being designed that will be networked for robust and redundant data gathering and wireless, stand-alone operation. The RF sensor will essentially function as a swept-frequency spectrum analyzer, measuring frequency content, amplitude and modulation characteristics over predetermined (or user programmable) bandwidths of interest. Recommendations and preliminary schematics for a compact, ruggedized, low-power RF sensor will be presented together with a design for a low-power centralized wireless network for data transfer and processing. The RF sensor technology developed in this effort will have a predominantly military application but should also find use in security and surveillance applications.
A handheld through-the-wall surveillance system is being developed for use by law enforcement and military personnel. The system utilizes high-power ultrasonic transducers to detect and locate stationary or moving persons inside metallic and non-metallic walled enclosures. Design details are presented with proof-of-concept data and analyses. The sensor system is being designed to operate as a handheld monitor with a near real-time user display of the location, in range and azimuth, of each detected individual. Preliminary test data include wall penetration/sensitivity, locating accuracy, and probability of detection. Applications of this technology include detecting and locating unconscious, sleeping, tightly bound, or otherwise stationary persons, as well as moving persons, inside a closed room. The sensor should also prove useful in border patrol applications for inspecting truck trailers and shipping containers at points of entry.
A system has been developed for delivering and attaching a sensor payload to a target using a standard 40-mm grenade launcher. The projectile flight characteristics are similar to existing 40-mm rounds, with a useful range of up to 300 m. The projectile incorporates an attachment mechanism, a shock mitigation system, a power source, and a transmitter that allows sensor data to be transmitted to a receiver at up to 1/4 mile range. Impact g-loads have been limited to less than 10,000 g's, enabling sensor payloads to be assembled using Commercial Off-The-Shelf components. The GLIMPS projectile is intended to be a general purpose delivery system for a variety of sensor payloads under the Unattended Ground Sensors program, with Phase I proof-of- concept being demonstrated using a low-power CMOS camera.
A handheld, battery-operated prototype of a remove concealed weapons detector has been built and tested. The concealed weapons detector will enable law enforcement and security officers to detect metallic and nonmetallic weapons concealed beneath clothing remotely from beyond arm's length to about 20 feet. These detectors may be used to: (1) allow hands-off, stand-off frisking of suspects for metallic and nonmetallic weapons; and (2) search for metallic and nonmetallic weapons on cooperative subjects at courthouse entrances and other monitored security portals. We have demonstrated that we image weapons concealed under heavy clothing, not just detect them, at ranges up to 15 feet using the same ultrasound frequency (40 kHz) used by commercial rangefinders. The concealed weapons detector operates much as a rangefinder, but at higher peak fluxes and pulse repetition frequencies. The detector alerts the user to concealed weapons audibly and visibly by detecting ultrasound glints above a body/clothing baseline, and by compensating for changing range and attenuation. The detector locates concealed weapons within a 6-inch illuminated spot at 10 feet. The signal processor eliminates any signal from behind the target.
A breadboard ultrasound sensor was developed for remotely detecting and imaging concealed weapons. The breadboard sensor can detect metallic and non-metallic weapons concealed on a human body under heavy clothing at ranges up to 8 m and image the concealed weapons at ranges up to 5 m. This breadboard sensor has produced the only remote ultrasound images of concealed weapons ever published, including lexan (plastic) knives and a handgun concealed under a heavy sweatshirt at 15 feet. The remote imaging by ultrasound was made possible by several new technological developments. The sensor includes a novel, highly efficient source of high-power, tunable ultrasound radiation suitable for remote imaging in air. Together with millimeter-sized, highly sensitive ultrasound detectors and high-gain transceivers, these advances make possible the centimeter- resolution imaging of concealed weapons at ranges between 1 m and 5 m. The ultrasound images are processed by our IMAGE binary-thresholding program, which filters for noise, frequency, brightness, and contrast. To be developed is a brassboard sensor with an imaging array of ultrasound detectors, capable of real-time, video-frame-rate imaging of weapons concealed on moving humans.
An integrated radar and ultrasound sensor, capable of remotely detecting and imaging concealed weapons, is being developed. A modified frequency-agile, mine-detection radar is intended to specify with high probability of detection at ranges of 1 to 10 m which individuals in a moving crowd may be concealing metallic or nonmetallic weapons. Within about 1 to 5 m, the active ultrasound sensor is intended to enable a user to identify a concealed weapon on a moving person with low false-detection rate, achieved through a real-time centimeter-resolution image of the weapon. The goal for sensor fusion is to have the radar acquire concealed weapons at long ranges and seamlessly hand over tracking data to the ultrasound sensor for high-resolution imaging on a video monitor. We have demonstrated centimeter-resolution ultrasound images of metallic and non-metallic weapons concealed on a human at ranges over 1 m. Processing of the ultrasound images includes filters for noise, frequency, brightness, and contrast. A frequency-agile radar has been developed by JAYCOR under the U.S. Army Advanced Mine Detection Radar Program. The signature of an armed person, detected by this radar, differs appreciably from that of the same person unarmed.
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