Global Navigation Satellite System Radio Occultation (GNSS-RO) refractivity climatologies for the stratosphere can be obtained from the Abel inversion of monthly average bending-angle profiles. The averaging of large numbers of profiles suppresses random noise and this, in combination with simple exponential extrapolation above an altitude of 80 km, circumvents the need for a “statistical optim...

Observatory monthly means provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, the uneven distribution of the present observatory network makes it difficult to determine the global field change pattern. Recently, we have developed an approach to extract satellite monthly means at a regular network of “virtual observatories” at ...

[1] Reliable global crustal field anomaly maps produced from magnetic measurements of the CHAMP satellite mission now allow for quantitative geological studies of crustal structure and composition. We have developed a GIS based forward modeling technique to model these anomaly maps. On the basis of the geologic and tectonic maps of the world, laboratory susceptibility values of the occurring ro...

[1] A gravity field acting on a collisionless, magnetized space plasma causes electrons and ions to drift into opposite directions, in addition to gyrating around the magnetic field lines. This sets up an electric current which flows perpendicular to the gravity and magnetic fields in the eastward direction. Here we present the first observational evidence for such a gravity-driven current syst...

The atmosphere sounding experiment of the German CHAMP (CHAllenging Minisatellite Payload) satellite mission was activated on February 11, 2001. Since then more than 110,000 occultations were recorded as of mid-December 2002. The results of nearly two years CHAMP GPS (Global Positioning System) occultation measurements and data analysis have shown, that significant improvements of the GPS radio...

The German geo-observations satellite CHAMP carries highly accurate vector instruments. The orientation of these relative to the inertial reference frame is obtained using star trackers. This Advanced Stellar Compass (ASC) is a fully autonomous unit, which provides, in real time, the absolute attitude with accuracy in the arc second range. In order to investigate the in-flight accuracy of the A...

In this paper we calculate explicitly the secular classical precessions of the node Ω and the perigee ω of an Earth artificial satellite induced by the static, even zonal harmonics of the geopotential up to degree l = 20. Subsequently, their systematic errors induced by the mismodelling in the even zonal geopotential coefficients Jl are compared to the general relativistic secular gravitomagnet...

[1] The CHAMP satellite continues to provide highly accurate magnetic field measurements from decreasing orbital altitudes (<350 km) at solar minimum conditions. Using the latest 4 years (2004–2007) of readings from the CHAMP fluxgate magnetometer, including an improved scalar data product, we have estimated the lithospheric magnetic field to spherical harmonic degree 120, corresponding to 333 ...