High Quality Content by WIKIPEDIA articles! USNS Observation Island (T-AGM-23), also known as ex-MA-28, ex-YAG-57, ex-EAG-154, Empire State Mariner , is one of two Missile Range Instrumentation Ships operated by the Military Sealift Command. One of the radars it carries is the AN/SPQ-11 Cobra Judy Passive electronically scanned array radar. USNS Observation Island operates worldwide, monitoring compliance with strategic arms treaties and supporting U.S. military weapons test programs. Observation Island carries an Air Force shipborne phased-array radar system for collecting data on missile tests. The ship is operated by Military Sealift Command for the Air Force Technical Applications Center at Patrick Air Force Base.