The Department of Defense, specifically the U.S. Air Force, is seeking proposals for the SBIR topic titled "APPEAR - Aperture Projects for Passive Engineering and Advanced Research." The objective of this initiative is to explore and develop innovative antenna aperture techniques and technologies that enhance the detection of various signals of interest, focusing on passive sensing systems that require minimal or no active transmissions. This effort is crucial for ensuring situational awareness in contested environments, particularly in the context of Great Power Competition, and aims to leverage commercial-off-the-shelf (COTS) capabilities to reduce costs and complexity. Proposals are due by June 25, 2025, and interested parties can find more information and submit their applications through the provided link: SBIR Topic Link.