[1] The Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC)/Formosa Satellite 3 (FORMOSAT-3) is a six-satellite radio occultation mission that was launched in mid-April, 2006. The close proximity of the COSMIC satellites provides a unique opportunity to estimate the precision of the radio occultation remote sensing technique from closely collocated occultations (<10 k...

First results from the GPS radio occultation experiment aboard the German CHAMP satellite are presented. The agreement between observed temperature profiles in the upper troposphere and the lower stratosphere and temperature profiles obtained from meteorological analyses is found to be below 1 K. The data processing and analysis system (operated by GeoForschungsZentrum Potsdam) has been success...

The FY3 (Feng-Yun-3) GNOS (GNSS Occultation Sounder) mission is a GNSS (Global Navigation Satellite System) radio occultation mission of China for remote sensing of Earth’s neutral atmosphere and the ionosphere. GNOS will use both the global positioning system (GPS) and the Beidou navigation satellite systems on the China FengYun-3 (FY3) series satellites. The first FY3-C was launched at 03:07 ...

Space based GPS measurements onboard Low Earth Orbiting (LEO) satellites provide a uniquepossibility for exploring the ionosphere on a global scale. Both the radio occultation measurements in thelimb sounding mode and the navigation measurements using a zenith viewing GPS antenna provide theTotal Electron Content (TEC) along numerous ray paths. TEC may effectively be used for re...

The New Horizons (NH) Radio Science Experiment, REX, is designed to determine conditions on Pluto as manifest in the atmospheric state at the surface and a few scale heights higher. Expected absolute accuracies in n, p, and T at the surface are 4·10 m−3, 0.1 Pa, and 3 K, respectively, obtained by radio occultation of a 4.2 cm-λ signal transmitted from Earth at 10–30 kW and received at the NH sp...

This research is motivated by the recent IGS Ionosphere Working Group recommendation issued at the IGS 2010Workshop held inNewcastle, UK. This recommendation encourages studies on the evaluation of the application of COSMIC radio occultation profiles for additional IGS global ionosphere map (GIM) validation. This is because the reliability of GIMs is crucial to many geodetic applications. On th...

Global Positioning System (GPS) radio-occultation (RO) is provided as a global sounding technique for obtaining atmospheric profiles by integrating them in global models for numerical weather prediction and for climate change studies. The radio occultation system employs GPS receivers placed on a Low-Earth Orbit (LEO) satellite to sound the Earth’s troposphere and ionosphere evaluating the addi...

Introduction Occultation methods based on effects connected with the refraction of electromagnetic waves in both the optical and radiofrequency domains have been used by astronomers for numerous investigations of planetary atmospheres over the last decades. The first experiment started with the Mars flyby by Mariner-IV in 1964. Since this first attempt, radio-occultation experiments have been c...