Issue 10 Volume 41 May 16, 2003

20030032920 Army Research Lab., Adelphi, MD
Detection and Localization with an Acoustic Array on a Small Robotic Platform in Urban Environments
Young, Stuart H.; Scanlon, Michael V.; Jan. 2003; 18 pp.; In English
Report No.(s): AD-A410432; ARL-TR-2575; No Copyright; Avail: CASI; A03, Hardcopy
Sophisticated robotic platforms with diverse sensor suites are quickly replacing the eyes and ears of soldiers on the
complex battlefield. The U.S. Army Research Laboratory (ARL) in Adelphi, Maryland, has developed a robot-based acoustic
detection system that will detect an impulsive noise event, such as a sniper’s weapon firing or a door slamming, and will
activate a pan tilt to orient a visible and infrared camera toward the detected sound. Once the cameras are cued to the target,
on-board image processing can then track the target and/ or transmit the imagery to a remote operator for navigation,
situational awareness, and target detection. Such a vehicle can provide reconnaissance, surveillance, and target acquisition for
soldiers, law enforcement, and rescue personnel and can remove these people from hazardous environments. ARL’s primary
robotic platforms contain 16-inch diameter, eight-element acoustic arrays. Additionally, a 9-inch array is being developed in
support of the Defense Advanced Research Project Agency tactical mobile robot program. The robots have been tested in both
urban and open terrain. The current acoustic processing algorithm has been optimized to detect the muzzle blast from a
sniper’s weapon and to reject many interfering noise sources such as wind gusts, generators, and self-noise.
DTIC
Image Processing; Target Acquisition; Armed Forces (United States); Guns (Ordnance); Sound Detecting And Ranging
20030032961 Woods Hole Oceanographic Inst., MA
Horizontal Linear Array Sensor Localization and Preliminary Coherence Measurements from the 2001 ASIAEX South
China Sea Experiment
Schroeder, Theodore H.; Sep. 2002; 106 pp.; In English; Original contains color illustrations
Contract(s)/Grant(s): N00014-95-1-005 1
Report No.(s): AD-A410435; No Copyright; Avail: CASI; A06, Hardcopy
This thesis examines data collected in the South China Sea (SCS) component of the 2001 Asian Seas International
Acoustic Experiment (ASIAEX), where a fixed Horizontal Linear Array (HLA) was deployed to study transverse array
coherence in a coastal environment. Arrays obtain their gain and directivity by coherently adding the energy that impinges on
them. Therefore, to maximize the efficiency of an array, the size of the aperture over which the signal remains coherent needs
to be determined. Scattering of sound by the ocean environment, especially in coastal areas, reduces the coherence of acoustic
signals, and thereby limits the useful aperture of an acoustic array. During ASIAEX, a horizontal linear array was deployed
on the continental shelf of the South China Sea in order to directly measure the acoustic coherence in a coastal environment.
224 Hz and 400 Hz sources were placed on the continental slope to provide an up slope propagation path and a 400 Hz source
was placed on the shelf to provide an along shelf propagation path. This thesis analyzes one day of transmissions from these
three sources and gives the first look at coherence lengths of the HLA determined by sensor-to-sensor correlations. To achieve
this, the thesis analyzes continuous time series data from the Long Base Line (LBL) navigation system and two days of light
bulb drops to provide array sensor localization. Accurate sensor positions are needed to determine the correlation versus sensor
separation distance and ultimately the array coherence length.
DTIC
Oceanography; Sound Waves; Linear Arrays; Acoustic Frequencies
20030032984 Drexel Univ., Philadelphia, PA
Progress in Cancer Diagnosis With Ultrasound
Reid, J. M.; Goldberg, B. B.; Shankar, P. M.; Forsberg, F.; Bilgutay, N.; Oct 2001; 4 pp.; In English
Report No.(s): AD-A410486; No Copyright; Avail: CASI; A01, Hardcopy
Despite successes in using ultrasound to characterize tissues at many sites in the body, the diagnosis of cancer, especially
in the female breast, has remained challenging. Besides devising methods to analyze the data, there are difficulties with
collecting data from enough patients to validate a variety of new methods, and in coping with changes in the hardware. We
have been conducting an integrated effort for nine years that has minimized these difficulties and is approaching success.
DTIC
Cancer; Mammary Glands; Ultrasonics; Diagnosis
20030032991 NASA Kennedy Space Center, Cocoa Beach, FL, USA
On the Propagation of Plane Acoustic Waves in a Duct With Flexible and Impedance Walls
Frendi, Abdelkader; Vu, Bruce; March 2003; 28 pp.; In English; Original contains color illustrations
Report No.(s): NASA/TM-2003-211185; NAS 1.15:211185; Copyright; Avail: CASI; A03, Hardcopy
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