The committee should also consider whether there are systems-level approaches that should be exploited. The committee should consider techniques for exploiting these characteristics. In undertaking this task, the committee may want to consider physical or chemical aspects of explosives that have not yet been exploited. The committee is tasked with both reviewing what detection systems now exist and trying to determine what could exist. True orthogonality is defined in terms of the false alarms that trigger the sensors, and not necessarily the signal that is being detected. Effective sensor fusion will depend upon the orthogonality of the sensors. Linking together different detectors for a systems approach to standoff explosives detection is desirable, but doing so must invoke a good systems approach. In order to meet this goal, it is necessary to consider the background in the field when explosives detection is being performed and both its impact on the explosives signal and its potential to contribute to false alarms. Requirements for standoff explosives detection are a high probability of detection combined with a low probability of false alarms. When considering standoff explosives detection, sensitivity and specific.
Detection of land mines is not a primary consideration for the NRC study.ĭARPA requests that the committee identify new approaches and new ways of thinking about the problem of standoff explosives detection. Low-probability, high-consequence situations such as these are the main priority for DARPA in its request for this study. A second scenario is the ability to detect a suicide bomber before the bomber is able to reach his or her target and detonate the explosive. The first is broad-area surveillance, particularly at events with large crowds such as the Super Bowl. Two main scenarios can be envisioned for the application of standoff explosives detection.
Standoff explosives detection is the ability to detect explosives at a distance. Finally, in view of the strengths and limitations of CHEETAH, recommendations for the future work are made.Lisa Porter, Defense Advanced Research Projects Agency (DARPA)ĭARPA has requested that the National Research Council (NRC) undertake the present study in order to address the issues and problems related to standoff explosives detection. However, if an experimentally determined radius of curvature is used, good results are achieved from Kinetic CHEETAH, reflecting non-ideal features such as detonation velocities dependent on charge radius. In attempting to apply CHEETAH 2.0 to PBXW-115Aust using the estimated radius of curvature for the detonation front built into the code, difficulties were initially encountered in achieving convergence to a self-propagating detonation velocity. It can replicate many of the features of non-ideal explosives such as detonation velocities and sonic reaction zone widths, and explosive properties such as detonation velocities as a function of the charge radius.
It is also shown that the CHEETAH 2.0 program based on the Wood-Kirkwood detonation theory can successfully model both mildly non-ideal explosives and moderate non-ideal explosives. It can also predict reasonably accurately experimental results for mildly non-ideal explosives. It is shown that the CHEETAH 2.0 program using the traditional Chapman-Jouget thermodynamic detonation theory can accurately model and predict performance of new explosive materials and of ideal explosives. It has also been used to study the effect of heats of formation and different types of binders on the predicted performance of explosive formulations. The Lawrence Livermore National Laboratory CHEETAH 2.0 program has been used to analyse a number of conventional ideal explosive ingredients, ideal explosive compositions, non-ideal explosive compositions, and new and proposed explosives.