This book presents carefully edited and peer-reviewed papers from the 2nd International Workshop on Occultations for Probing Atmosphere and Climate (OPAC-2), held in Graz, Austria. It starts with a general introductory paper and proceeds to address the full range from methodology in general via specific occultation methods (GNSS-LEO, LEO-LEO, stellar and solar) to the use of occultation data, with focus on atmospheric physics, meteorology and climate.

Building on its heritage in planetary science, remote sensing of the Earth s at- sphere and ionosphere with occultation methods has undergone remarkable dev- opments since the rst GPS/Met proof of concept mission in 1995. Signals of Global Navigation Satellite Systems (GNSS) satellites are exploited by radio occ- tation while natural signal sources are used in solar, lunar, and stellar occultations. A range of atmospheric variables is provided reaching from fundamental atmospheric parameters such as density, pressure, and temperature to water vapor, ozone, and othertracegasspecies....

Use of occultation methodology for observing the Earth's atmosphere and climate has become so broad as to comprise solar, lunar, stellar, navigation and satellite crosslink occultation methods. The atmospheric parameters obtained extend from the fundamental variables temperature, density, pressure, water vapor, and ozone via a multitude of trace gas species to particulate species such as aerosols and cloud liquid water. Ionospheric electron density is sensed as well. The methods all share the key properties of self-calibration, high accuracy and vertical resolution, global coverage, and (if...

Since the early use of the occultation measurement principle for sounding pla- tary atmospheres and ionospheres, its exploitation in atmospheric remote sensing has seen tremendous advances. In this book we focus on sensors on Low Earth Orbit (LEO) satellites, which exploit solar, lunar, stellar, GNSS (Global Navi- tion Satellite Systems), and LEO-crosslink signals for observing the Earth's - mosphere and climate. The methods all share the key properties of self-calibration, high accuracy and vertical resolution, global coverage, and (if using radio signals) all-weather ca- bility. The...