Book excerpt: "Field Guide to Infrared Systems, Detectors, and FPAs, Third Edition is devoted to fundamental background issues for optical detection processes. It compares the characteristics of cooled and uncooled detectors with an emphasis on spectral and blackbody responsivity, detectivity, as well as the noise mechanisms related to optical detection. It introduces the concepts of barrier infrared detector technologies, and encompasses the capabilities and challenges of third-generation infrared focal plane arrays as well as the advantages of using dual-band technology. The book combines numerous engineering disciplines necessary for the development of an infrared system. It considers the development of search infrared systems and specifies the main descriptors used to characterize thermal imaging systems. Furthermore, this guide clarifies, identifies, and evaluates the engineering tradeoffs in the design of an infrared system"--