The secondary research process involved comprehensive analysis of defense procurement databases, aerospace engineering journals, materials science publications, and authoritative defense organizations. Key sources included the US Department of Defense (DoD), North Atlantic Treaty Organization (NATO) Research & Technology Organization, European Defence Agency (EDA), Defense Advanced Research Projects Agency (DARPA), American Institute of Aeronautics and Astronautics (AIAA), Society for the Advancement of Material and Process Engineering (SAMPE), National Institute of Standards and Technology (NIST), US Government Accountability Office (GAO) Defense Reports, Stockholm International Peace Research Institute (SIPRI) Arms Transfer Database, International Institute for Strategic Studies (IISS) Military Balance, and defense ministry procurement reports from key markets including the US, UK, Germany, France, China, India, and Japan. These sources were used to collect defense spending data, military modernization programs, radar cross-section (RCS) reduction standards, substrate compatibility studies, and market landscape analysis for radar absorbing materials (RAM), plasma stealth technologies, active camouflage systems, and other stealth coating technologies.