Ivan Kadar, Eloi Bosse, John Salerno, Dale A. Lambert, Subrata Das, Enrique H. Ruspini, Bradley J. Rhodes, and Joachim Biermann “Results from levels 2/3 fusion implementations: issues, challenges, retrospectives, and perspectives for the future an annotated perspective”, Proc. SPIE 6968, Signal Processing, Sensor Fusion, and Target Recognition XVII, 696812 (6 May 2008); https://doi.org/10.1117/12.782740
Even though the definition of the Joint Director of Laboratories (JDL) “fusion levels” were established in 1987, published 1991, revised in 1999 and 2004, the meaning, effects, control and optimization of interactions among the fusion levels have not as yet been fully explored and understood. Specifically, this is apparent from the abstract JDL definitions of “Levels 2/3 Fusion” – situation and threat assessment (SA/TA), which involve deriving relations among entities, e.g., the aggregation of object states (i.e., classification and location) in SA, while TA uses SA products to estimate/predict the impact of actions/interactions effects on situations taken by the participant entities involved. Given all the existing knowledge in the information fusion and human factors literature, (both prior to and after the introduction of “fusion levels” in 1987) there are still open questions remaining in regard to implementation of knowledge representation and reasoning methods under uncertainty to afford SA/TA. Therefore, to promote exchange of ideas and to illuminate the historical, current and future issues associated with Levels 2/3 implementations, leading experts were invited to present their respective views on various facets of this complex problem. This paper is a retrospective annotated view of the invited panel discussion organized by Ivan Kadar (first author), supported by John Salerno, in order to provide both a historical perspective of the evolution of the state-of-the-art (SOA) in higher-level “Levels 2/3” information fusion implementations by looking back over the past ten or more years (before JDL), and based upon the lessons learned to forecast where focus should be placed to further enhance and advance the SOA by addressing key issues and challenges. In order to convey the panel discussion to audiences not present at the panel, annotated position papers summarizing the panel presentation are included.