The objective of this research is to validate observations of atmospheric temperature derived by occulation methods from data from the Global Positioning System. Temperature profiles obtained from the GPS data show large-amplitued oscillations at heights between 10 km and 60 km. The principal investigator will collaborate with colleagues at the University of Adelaide in Australia on a project to compare high-resolution sounding data from weather balloons with the data derived from the GPS to determine whether the temperature oscillations are truly indicators of atmospheric waves. If these are truly waves, the GPS data provide an opportunity to monitor such waves globally. It is important that we understand these waves because of their potential effects on climate and global circulation.