This paper extends previous work on the inversion of line profiles to obtain wind velocity laws to a case that includes the occultation of light from the far side of the star. The velocity law v(r) is assumed to be from a wind that is steady and spherically symmetric. The wind is also assumed to be optically thin in the emission line profile. Themajor result here is the derivation of an analyti...

Introduction On July 17, 1995 the U.S. Air Force announced “ .. that today the Global Positioning System (GPS) satellite constellation has met all requirements for Full Operational Capability”. Apart from precise positioning GPS signals also can be used to derive characteristic properties of the propagation medium (neutral atmosphere and ionosphere). Onboard the Low-Earth-Orbiting MICROLAB-1 sa...

The atmospheric propagation of GPS signals under multipath conditions and their detection are simulated. Using the multiple phase screen method C/A-code modulated L1 signals are propagated through a spherically symmetric refractivity field derived from a high-resolution radio sonde observation. The propagated signals are tracked by GPS receivers implemented in software and converted to refracti...

The German geoscience satellite CHAMP (CHAllenging Minisatellite Payload, launched on July 15, 2000, Reigber et al., 2002) is in orbit now for more than 2 years. CHAMP's measurements are used to determine Earth's gravity and magnetic field and to derive precise information about vertical temperature, humidity and electron density distribution on a global scale using the innovative GPS radio occ...

The stellar occultation technique provides competitive accuracy in determining the sizes, shapes, astrometry, etc., of occulting body, comparable to in-situ observations by spacecraft. With increase number known Solar System objects expected from LSST, highly precise astrometric catalogues, such as Gaia, and improvement ephemerides, occultations will become more common with a higher chords each...