The Department of Defense, specifically the United States Air Force, is seeking innovative solutions through the Small Business Innovation Research (SBIR) program to develop effective sensor technologies for the detection of small uncrewed aircraft systems (UAS) operating in cluttered environments. The primary objective is to create a system capable of autonomously detecting low-flying UAS that may be obscured by trees or buildings, addressing the challenges posed by these threats to military installations. This initiative is critical for enhancing air defense capabilities, particularly as UAS technology evolves and enables coordinated swarm tactics that complicate detection efforts. Interested parties should note that the solicitation is open from April 2, 2025, to May 21, 2025, with proposals required to demonstrate a prototype capable of achieving at least 80% detection effectiveness and less than 20% false alarms during Phase II. For more details, applicants can refer to the solicitation document available at SBIR.gov.