the ASPs generate spectrum output data files in a standardized format to enable off-line analysis of the gamma spectra by a separate program (section 7.1.4 of the DNDO 2007). Such standardized output ought to result in modularity of the software, enabling interchange of analysis algorithm computer modules. Although the ASPs do produce the gamma spectrum output data files, at least one of the vendors uses a different data file containing additional information for its own analyses, so that vendor’s analysis software cannot reproduce its own results through offline analysis of the output data file. As a result, the analysis modules produced to date are not compatible with each other’s detector systems. Within the committee, this raised concerns about procurement: DNDO has not gotten the modularity from the vendors that was mandated in the specification. This deficiency should be corrected.

Furthermore, DNDO should not limit itself to the vendors’ algorithms. It is possible that the DHSIsotopeID package, developed at Sandia National Laboratories, or another algorithm is superior to those provided by the ASP vendors. Existing isotope identification algorithms have been developed by a very small community of researchers. DNDO should encourage a broader effort to address these challenges, additionally engaging experts outside of nuclear detection to assist in evaluation and modification of the analysis algorithms. Algorithms for spectral and image analysis in complex systems are found in many fields, including astronomy, medical imaging, and atmospheric analysis, and expertise developed in those areas could be applied to all of the spectroscopic detectors, including the ASP system.

CONCLUSION

The committee has identified the merits and shortcomings of the work DNDO has done in testing and evaluating ASPs, and described how to address the shortcomings. Much of the committee’s advice applies regardless of DHS’ chosen path. For example, modeling and simulations should play a larger role in testing and evaluation whether DHS selects ASPs, handheld detectors, both, or another technology. For any acquisition decision, DHS should use figures of merit that reflect the performance of the systems accurately and are meaningful to the decision factors. Regarding cost-benefit analyses, the acquisition decision should be placed within the larger context of strategies and decisions. The analysis should be only as quantitative as the data can support, and conversely a reasoned justification may be more appropriate than a quantitative analysis in some cases. The set of alternatives under consideration should reflect the options the decision maker would want to know about, not just the options fully available at a particular time. It may be that the preferred option is within that broader set. Finally, DHS should be building a program that is structured around learning that leads to continuous improvement of systems to be deployed operationally in the field.

Thank you for the opportunity to provide input to your decisions.

The Committee on Advanced Spectroscopic Portals

Robert C. Dynes, Chair John M. Holmes
Richard Blahut Karen Kafadar
Robert R. Borchers C. Michael Lederer
Roger L. Hagengruber Keith W. Marlow
Carl N. Henry John W. Poston, Sr.


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement