In the 30 years since the publication of the paper by Colin Hines on Atmospheric Gravity Waves (AGW) in the ionosphere, hundreds of papers describing theoretical and experimental investigations of AGW sources and propagation phenomena have been published (see reviews by Yeh and Liu [1974], Francis [1975] and Hunsucker [1982]). Several global campaigns called “Worldwide Atmospheric Gravitywave Studies (WAGS)” [Argo and Hunsucker, 1985] have been carried out, and results of the WAGS 1 campaign of October 14–19, 1985, were reported in a special issue of Radio Science [Argo and Hunsucker, 1988] and in several other journals.