We present recent results from our ongoing lunar occultation program on binary stars at the TIRGO and Calar Alto observatories. Observations are presented here for a total of seventeen sources, the majority of which are resolved for the first time. These include SAO 94621, IRAS 18154-1900, SAO 98345, SAO 98363, SAO 93947, SAO 97319, SAO 97437, SAO 94986, SAO 94488, DO 11742, SAO 78027 and SAO 7...

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...

The Taiwanese-American Occultation Survey (TAOS) operates four telescopes to search for occultations of stars by Kuiper Belt Objects. This paper provides a detailed description of the TAOS multi-telescope system. Subject headings: Solar System, Astronomical Instrumentation, Astronomical Techniques

Ionospheric tomography using GPS data has been reported in the literature and even the application to radar altimeter calibration was succesfully carried out in a recent work ( [1]). We here present a new software tool, called Global Ionospheric Stochastic Tomography software (GIST), and its powerful capability for ingesting GPS data from different sources (ground stations, receivers on board L...

Validation studies of current GPS radio occultation experiments using meteorological analyses consistently report on a negative refractivity bias in the lower troposphere. It is shown that refractivity profiles obtained from Doppler-inverted bending angle profiles not only deviate significantly within zones of multipath propagation but also depend on the selected end point of the occultation si...

We combine GPS/MET data from 29 occultations and IGS ground data collected from 160 stations around the world to perform stochastic tomography of the ionosphere with a 4×20×20 global grid of voxels extending from 200 to 650 km above the mean surface of the Earth. A correlation functional approach that limits the spatial high frequency content of the images is used, and a Kalman filter is applie...