Albedo reflectance and bi-hemispherical reflectance (e.g.,). These calculations are based on the bidirectional reflectance distribution function (BRDF), which describes how the reflectance of a given surface depends on the view angle of the observer and the solar angle. BDRF can facilitate translations of observations of reflectance into albedo. Earth's average surface temperature due to its albedo and the greenhouse effect is currently about 15 °C. If Earth were frozen entirely (and hence be more reflective), the average temperature of the planet would drop below −40 °C. If only the continental land masses became covered by glaciers, the mean temperature of the
Surface-to-surface missile for LRBM, and thus defines an ICBM as those missiles with ranges greater than 5,500 km (3500 mi). The International Institute for Strategic Studies also does not define a range for LRBMs, and defines SRBMs as having somewhat shorter ranges than the definition used by the Department of Defense. Surface-to-surface missile A surface-to-surface missile (SSM) or ground-to-ground missile (GGM) is a missile designed to be launched from the ground or the sea and strike targets on land or at sea. They may be fired from hand-held or vehicle mounted devices, from fixed installations, or from a ship. They are often