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
Javelin (surface-to-air missile) Javelin (surface-to-air missile) Javelin is a British man-portable surface-to-air missile, formerly used by the British Army and Canadian Army. It can be fired from the shoulder, or from a dedicated launcher known as Javelin LML: Lightweight Multiple Launcher. Capable of being vehicle mounted, the LML carries three rounds. It was replaced in front line British service by the Javelin S-15, sold commercially as the Starburst surface-to-air missile in 1993 (radio frequency guided Javelin was retained for some time thereafter for training purposes), and later by the Starstreak starting around 1997. The Javelin GL was hastily purchased by the Canadian Forces