The Department of Defense (DoD) established an Executive Agent for the DoD’s Non-Lethal Weapons Program in 1996. DoD Directive 3000.03E, DoD Executive Agent for Non-Lethal Weapons (NLW), and NLW Policy<sup>1</sup> defines policies and responsibilities for the development and employment of non-lethal weapons. It also designates the Commandant of the Marine Corps as the DoD NLW Executive Agent with the responsibility to serve as the DoD focal point on all matters. An important component of this responsibility is development of the DoD’s NLW technology development strategy and investment in promising technologies that will enable advanced nonlethal capabilities to support the warfighter in future operating environments.
During May 1997 - October 1998, SPAWARSYSCEN Code D746, under the sponsorship of the Defense Advanced Research Projects Agency (DARPA), conducted several field tests using off-the-shelf (OTS) 900 MHz wireless modems in different operating environments, typical of those targeted by unattended ground sensor (UGS) applications. Using ground-based 12 inch (mounted on 3 inch base) 3dB onmidirectional antennas on both communication ends, the performance of three OTS modems was evaluated. By varying path lengths, baud rates, file sizes, RF environments, and degrees of line of sight (LOS), a comprehensive profile of each modem's performance was established. Because of the nature of ground-level communications (varied LOS) and the many environmental variables which can dramatically affect performance, this paper does not attempt to model performance or draw conclusions as to which modem is best suited for all UGS applications. However, based on the results of these field tests, the OTS modem using frequency hopping spread spectrum (FHSS) performed considerably better than the two other OTS modems using direct sequence spread spectrum. This certainly could be attributed to the poor quality of the two DSSS modems used in the field tests, and a more comprehensive side-by-side comparison is recommended. In addition, the paper does offer insight into the limitations of the OTS wireless modems, and demonstrates how greater degrees of LOS can tremendously boost their range and reliability.
Thermal infrared propagation data has been collected across the surf influenced marine atmospheric
boundary layer as a part of the Electro-Optical Propagation in a Coastal Environment (EOPACE) surf zone
experiment. This data was collected at Scripps Pier, La Jolla, California in January-February 1996.
Preliminary analysis shows that the changes in transmittance are highly correlated with changes in bulk
environmental parameters such as wind speed and direction, humidity, and marine haze. The effect of wave
height is unclear from this preliminary analysis. An unexpected result was the up to 30% drop in
transmission measured during the transition period when the wind speed drops and the air mass flow
changes direction. This change occurs in the evening when the wind changes direction from onshore to
offshore and in the morning when the wind changes from offshore to onshore. A similar drop in
transmittance was not found under any other conditions. This is possibly due to the topography of the site
with the steep hill rising up from the beach. The onshore-offshore flow may be very much influenced by this
During October 1995 through May 1996, the Defense Advanced Research Projects Agency sponsored the development of prototype systems that exploit acoustic muzzle blast and ballistic shock wave signatures to accurately predict the location of gunfire events and associated shooter locations using either single or multiple volumetric arrays. The output of these acoustic systems is an estimate of the shooter location and a classification estimate of the caliber of the shooter's weapon. A portable display and control unit provides both graphical and alphanumeric shooter location related information integrated on a two- dimensional digital map of the defended area. The final Phase I Acoustic Systems Demonstration field tests were completed in May. These these tests were held at USMC Base Camp Pendleton Military Operations Urban Training (MOUT) facility. These tests were structured to provide challenging gunfire related scenarios with significant reverberation and multi-path conditions. Special shot geometries and false alarms were included in these tests to probe potential system vulnerabilities and to determine the performance and robustness of the systems. Five prototypes developed by U.S. companies and one Israeli developed prototype were tested. This analysis quantifies the spatial resolution estimation capability (azimuth, elevation and range) of these prototypes and describes their ability to accurately classify the type of bullet fired in a challenging urban- like setting.
During October 1995 - June 1996, the Naval Command, Control and Ocean Surveillance Center RDT&E Division (NRaD), under sponsorship from Defense Advanced Research Projects Agency (DARPA), conducted an intensive series of multi-spectral signature analyses of typical sniper weapons. Multi-spectral signatures of the muzzle flashes from rifles and pistols and some imagery of the bullets in flight were collected. Multi- spectral signatures of the muzzle flash were collected in the infrared (2.5 - 14.5 microns), visible -- near-IR (400 - 1200 nanometers), and the ultra-violet (185 - 400 nanometers) wavelength regions. These measurements consisted of high spectral resolution (0.0159 micron) measurements of the spectral radiance of the muzzle flash. A time history plot of the muzzle flash as it evolves just forward of the end of the muzzle is provided. These measurements were performed with a CI Systems Model SR5000 IR/Visible spectroradiometer and an Ocean Optics Model PC1000 UV spectroradiometer. Muzzle flash infrared imagery is provided to show the effect that specific muzzle breaks have on the resulting muzzle flash. The following set of sniper weapons were included in this test: AK-47, SKS, M16A2, M-14, FN-FAL, SMLE IIa, 03 Springfield, SVD Dragunov, 50 caliber McMillan, and a 45 caliber ACP pistol. The results of this signature analysis show that important measurable electro-optical differences do exist between all these weapons in terms of spectral radiance of the flash, spectral content of the gun powders, and spectral shapes/geometries of the muzzle flashes. These differences were sufficient such that, after a more complete data base is collected, it will be possible to develop a passive electro-optical weapon and ammunition identifier.
Atmospheric transmission measurements have been made along a horizontal path through the marine atmospheric boundary layer have been made. Measurements were made in the thermal infrared region at an average spectral resolution of 0.018 micrometer in the 3 - 5 micrometer region and 0.06 micrometer in the 8 - 14 micrometer region. The Vindeby, Denmark site provided conditions of moderate wind speeds and moderate to high humidities. Both land and sea fetch conditions were encountered. Measured transmission is compared to LOWTRAN 7 predictions. Midlatitude Winter atmospheric profiles were used in conjunction with the rural aerosol model for the land fetch conditions and the Navy Maritime aerosol model for the sea fetch conditions. It was found that neither model gave the same spectral content as the measured data although the magnitude of broad band transmission was similar. It is apparent that further transmission measurements must be made in conjunction with gas, aerosol, and other environmental parameters for adequate LOWTRAN 7 model validation in the marine atmospheric boundary layer.