EOP

EOP is an acronym that can refer to several different concepts depending on the context. Three of the most common meanings are Earth Orientation Parameters, Emergency Operations Plan, and the Executive Office of the President.

Earth Orientation Parameters describe the irregularities in the Earth's rotation and orientation relative to space. They are used to transform coordinates between the celestial reference frame and the terrestrial frame and to keep time scales consistent. The parameters typically include polar motion components and the difference between UT1 and UTC. They are maintained by international organizations such as the International Earth Rotation and Reference Systems Service (IERS) and are determined from geodetic and astronomical observations, including very-long-baseline interferometry (VLBI) and satellite tracking. EOPs are essential for high-precision astronomy, satellite navigation, and geodesy.

Emergency Operations Plan refers to a formal document that outlines how an organization or government will respond to emergencies and disasters. An EOP defines roles, responsibilities, activation criteria, incident command structures, communications procedures, resource management, continuity of operations, and training and exercises. It aims to coordinate actions across agencies and departments, ensure safety, protect property, and support quick recovery.

Executive Office of the President is the collective set of agencies and staff that support the President of the United States. The EOP includes offices such as the White House Office, the Office of Management and Budget, the National Security Council, and other policy and administrative units. Its purpose is to provide policy analysis, coordination, communications, and administrative support to the presidency.

Other uses of the acronym exist in education, business, and technology, but the intended meaning is typically clear from context.