Global Navigation Satellite System Radio Occultation: Processing Algorithms, Science Applications, and COSMIC-2 Mission Status

Abstract:

Global Navigation Satellite System (GNSS) Radio Occultation (RO) data are becoming a benchmark dataset of the international global observing system. The high vertical resolution, precision, and accuracy of retrieved atmospheric profiles makes GNSS RO ideal for weather and space weather specification and forecasting, climate change research and detection, and ground-based and satellite instrument validation. With a GNSS receiver on board a low-Earth orbiting (LEO) satellite, the amplitude and phase of the radio frequency (RF) signals transmitted from GNSS satellites can be measured very precisely as the ray tangent point descends from ~100 km altitude to the surface. With proper algorithms and observational modeling, vertical profiles of bending angle are derived. Profiles of refractivity, and subsequently pressure, temperature and humidity can be derived with additional a priori information. This presentation will first provide an overview of GNSS RO data processing algorithms and then present recent research results from challenging regions such as the upper stratosphere and the lower troposphere. Additional research results from science application studies using RO data will also be discussed. Finally, a status update of the COSMIC-2 mission due to launch in Sept 2016 will be presented.