architectures. Chapter 10 also provides more specific insight into factors that influence overall performance, including those that are outside the detection system.

The scenarios and defensive concepts in this report were created to provide guidance on the environments and top-level requirements for the detection systems that enable detect-to-warn architectures. Development of more detailed system specifications and operational concepts was not undertaken as part of this study. Future design efforts that address detect-to-warn systems and their operations must build upon the growing experience base derived from federal demonstration programs, including DoD and its Advanced Concept Technology Demonstration (ACTD) programs. Several past ACTDs (for example, the Joint Biological Remote Warning System) addressed biological defense operations in the field. More recent work in the Restoration of Operations ACTD has focused on protection and response to chemical and biological attacks on fixed sites. The operational concepts developed in these past demonstration programs should be evaluated in future system design studies, although they may be of limited value since none have focused on the detect-to-warn architectures discussed in the study. In addition, a formal red teaming3 and countermeasure evaluation must be a part of the next stages of defensive architecture design. The committee did not evaluate the tactics that could be employed by an attacker to defeat the conceptual defenses postulated in this report.

It should also be noted that the detect-to-warn approaches outlined here are not the only component in a comprehensive system to protect personnel from the effects of a biological attack. An overall biodefense architecture can include medical countermeasures (e.g., vaccines and therapeutics) as well as personal and collective protection systems. An approach for balancing research, development, and deployment efforts in this larger arena is an important research topic but is beyond the scope of this study.


Credible scenarios for biological agent release against targets of concern are the starting points for development of defensive concepts and detection system requirements. Attack scenarios can generally be divided into two categories. The first involves outdoor releases designed to threaten distributed target complexes (e.g., military bases, deployed forces, naval task forces) or broad area targets (e.g., cities). The second involves direct attacks on specific facilities through agent release into an interior area or into the intake of the air handling system.

Outdoor Release Scenarios

Outdoor releases that cover a distributed area have long been a focus of military concern. Such attacks can threaten forces in the field, operational bases, seaborne task forces, and other critical power projection assets. Outdoor attacks that employ a fully weaponized agent exploit the full potential for wide area impact offered by biological agents. The scenarios developed in an earlier study effort and provided in support of committee deliberations4 emphasize the effect of outdoor releases on a variety of military targets. These scenarios usually employ a line release of aerosolized agent, although the type of agent employed, the timing and extent of the attack, and the resulting areas impacted differ widely. Others have postulated similar broad area attacks on U.S. cities, frequently employing the same line release deployment schemes.5 While line releases are often the tactic of choice, other options, including point releases, may be more suitable for less sophisticated attackers, for surreptitious release in a protected area, for attack of specific targets, or in response to defensive system deployments.


A "red team" is a group of independent reviewers organized to provide an objective assessment.


Advanced Systems Concepts Office, Defense Threat Reduction Agency, 2000. NBC Scenarios: 2002-2010, April.


U.S. Congress, Office of Technology Assessment. 1993. Proliferation of Weapons of Mass Destruction: Assessing the Risk, OTA-ISC-559. Washington, D.C.: U.S. Government Printing Office. Available online at

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