There is widespread interest in the development of advanced fire detectors. A primary objective of fire detection is to provide prompt indication of the presence of a fire, without responding to deceptive signatures from nuisance sources. The principal purpose of this project is to identify the characteristics of a discriminating fire detector for Naval shipboard applications incorporating ionization, photoelectric, carbon dioxide and carbon monoxide sensors. Test data from previously conducted full-scale tests involving fire and nuisance sources are being analyzed to develop an algorithm involving combinations of the magnitude or slope of the response signal from each sensor. Acceptability of a particular algorithm is judged based on the number of correct classifications (fire vs. nuisance) and response time to fire sources.