With the availability of approximately 4,000 radio occultation soundings per day within three hours of observation, COSMIC has the potential to contribute significantly to global and regional weather analysis and prediction. However, the basic radio occultation measurements (phase delays) are very different from traditional meteorological measurements (i.e., temperature, water vapor), and to ef...

The radio occultation (RO) technique, employing the GPS constellation of satellites and radio receivers in low earth orbit, can provide valuable atmospheric profile information (Ware et al. 1996; Kursinski et al. 1996; Rocken et al. 1997; Wickert et al. 2001). The radio occultation technique has been long used in the study of planetary atmospheres (e.g. Fjeldbo et al. 1971) where it has provide...

A radio holographic approach, developed by Pavelyev (1998), Hocke et al. (1999), Igarashi et al. (2000), is applied to observation of wave phenomena in the upper atmosphere using Global Positioning System "Microlab-l" satellite (GPS/MET) radio occultation data. In the current state the radio holography approach uses the radar focused synthetic aperture principle to obtain high spatial resolutio...

In this study a nonlocal, linear observation operator for assimilating radio occultation data is evaluated. The operator consists of modeling the excess phase, that is, integrating the refractivity along straight lines tangent to rays, below a certain height. The corresponding observable is the excess phase integrated through the Abel-retrieved refractivity, along the same lines, below the same...

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Faraclay rotation observations are unique amongst radio occultation mcasurcmcnts in that they respond to magnetic field in addition to e.lcctron density, making it possible to probe the coronal magnetic field. Transients observed by Pioneer 6 Faraday rotation measurements in 1968 in the heliocentric distance range of 6-11 R. arc shown to be caused by the radially expanding coronal streamer stal...

[1] We present the Radio Occultation Scintillation Simulator (ROSS), which uses the multiple phase screen method (MPS) to simulate the forward scatter of radio waves by irregularities in the equatorial ionosphere during radio occultation experiments. ROSS simulates propagation through equatorial plasma bubbles which are modeled as homogeneous electron density fluctuations modulated by a Chapman...

[1] Radio occultation remote sensing of the Earth’s atmosphere by use of GPS encounters problems in the moist lower troposphere (planetary boundary layer). The negative errors in retrieved refractivity (bias) may not be explained by the horizontal inhomogeneity in refractivity. In part, these errors can be attributed to the use of signal tracking algorithms inappropriate for the complicated str...

At the end of September 2009, a new Italian GPS receiver for radio occultation was launched from the Satish Dhawan Space Center (Sriharikota, India) on the Indian Remote Sensing OCEANSAT-2 satellite. The Italian Space Agency has established a set of Italian universities and research centers to implement the overall processing radio occultation chain. After a brief description of the adopted alg...

In this study we have proposed a method based on neural networks to retrieve refractivity, temperature, pressure and humidity profiles by using FORMOSAT-3/COSMIC GPS radio occultation data. To overcome the constraint of an independent knowledge of one atmospheric parameter at each GPS occultation, we trained three neural networks with refractivity profiles as input computed from the geometrical...