Decoys and Discrimination in Intercept Test IFT-8

The document analyzes the target suite for the IFT-8 missile defense test, arguing that the addition of small balloon decoys does not significantly increase the difficulty of the discrimination task. The authors contend that the kill vehicle's infrared sensors can easily distinguish these decoys from the mock warhead because their infrared signals differ substantially in brightness. Furthermore, the paper criticizes the discrimination methodology for relying on 'reference data'—detailed prior knowledge of target characteristics—which the authors describe as an unrealistic operational assumption.

• The IFT-8 test increases the number of decoys by adding two small balloons to the existing single large balloon, but this does not meaningfully increase the difficulty of discrimination because the balloons' infrared signals differ significantly from the mock warhead.
• The discrimination process for the GMD system relies on comparing real-time sensor data to a set of 'reference data' containing predicted characteristics of target objects, an approach the authors deem highly unrealistic for actual combat scenarios.
• The kill vehicle's infrared sensors cannot determine the shape of objects until they are very close—approximately 1 to 2 seconds before impact—meaning objects appear only as points of light until it is too late to significantly change course.
• Previous tests used a 2.2-meter large balloon that was approximately six times brighter than the mock warhead, making it easy to distinguish; later tests (IFT-6 and 7) used a 1.7-meter balloon that remained more than three times brighter than the warhead.
• Medium balloons were excluded from IFT-8 due to reliability concerns regarding their deployment and the fact that their brightness is very similar to the mock warhead, which would make discrimination more difficult.
• The authors argue that past intercept tests (IFT-3 through 7) did not occur under operationally realistic conditions, noting that closing speeds were up to two times lower than expected for an operational system.

APA

Wright, D., & Gronlund, L. (2002). Decoys and Discrimination in Intercept Test IFT-8. Union of Concerned Scientists. https://www.ucs.org/sites/default/files/2019-09/acfxoq64k.pdf

Chicago

Wright, David, and Lisbeth Gronlund. Decoys and Discrimination in Intercept Test IFT-8. Union of Concerned Scientists, 2002. https://www.ucs.org/sites/default/files/2019-09/acfxoq64k.pdf.

Wikipedia

{{cite report |last1=Wright |first1=David |last2=Gronlund |first2=Lisbeth |title=Decoys and Discrimination in Intercept Test IFT-8 |publisher=Union of Concerned Scientists |date=14 March 2002 |url=https://www.ucs.org/sites/default/files/2019-09/acfxoq64k.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{wright2002decoys, author = {Wright, David and Gronlund, Lisbeth}, title = {{Decoys and Discrimination in Intercept Test IFT-8}}, institution = {Union of Concerned Scientists}, year = {2002}, month = mar, url = {https://www.ucs.org/sites/default/files/2019-09/acfxoq64k.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }