Global models of the Earth’s gravitational field can be divided among three primary classes: satellite-only, combined and tailored models. Some of the current deficiencies in some of these models will be outlined using examples over Australia. The new dedicated satellite gravity field missions (e.g., GRACE, CHAMP and GOCE) will make significant improvements to the long-wavelength, satellite-der...

The German Satellite CHAMP (Challenging Minisatellite Payload) has the unique ability to measure the surface forces present. The total density can be easily derived from this measurement, with the help of models of solar radiation pressure and Earth’s albedo. This total density will be compared with the total density from two models, MSIS-86 (Hedin, 1987) and DTM-78 (Barlier et al., 1977). The ...

The new satellite missions CHAMP, GRACE and GOCE will provide significantly improved global gravity field information in terms of quality and spatial resolution. In order to quantify the quality of these gravity field models independently from the estimation procedure, new validation concepts are necessary using external information. Validation requires the processing of selected level 3 produc...

[1] The paper deals with initial analyzes of radio occultation measurements of the ionosphere carried out on board the CHAMP satellite since 11 April 2001. The accuracy of the operationally retrieved electron density profiles has been estimated by comparing with independent measurements. The derived ionospheric key parameters such as f0F2 and hmF2 agree with a standard deviation of 18 and 13%, ...

The relevance of water vapour in atmospheric physics and climate research contrasts strongly with the availability of humidity data in the Arctic. The most extensive humidity data set is based on approx. 80 radiosonde stations north of 60°N, but suffers from two major problems: Sensor diversity and sensor limitations under Arctic conditions, on the one hand, and lacking radiosonde launch sites ...

In this paper we estimate zonal plasma drift in the equatorial ionospheric F region without counting on ion drift meters. From June 2001 to June 2004 zonal plasma drift velocity is estimated from electron, neutral, and magnetic field observations of Challenging Mini-satellite Payload (CHAMP) in the 09:00–20:00 LT sector. The estimated velocities are validated against ion drift measurements by t...

Performance of a recently proposed technique for gravity field modeling has been assessed with data from the CHAMP satellite. The modeling technique is a variant of the acceleration approach. It makes use of the satellite accelerations that are derived from the kinematic orbit with the 3-point numerical differentiation scheme. A 322-day data set with 30-s sampling has been used. Based on this, ...

The Defense Meteorological Satellite Program (DMSP) launches and maintains a network of satellites to monitor the meteorological, oceanographic, and solar-terrestrial physics environments. In the past decade, geomagnetic field modelers have focused much attention on magnetic measurements from missions such as CHAMP, Ørsted, and SAC-C. With the completion of the CHAMP mission in 2010, there has ...

This paper examines whether the radio occultation (RO) measurements of the tropopause region are able to improve radiometric tropospheric profile retrievals, as represented by the ATOVS (Advanced TIROS Operational Vertical Sounder) temperature and humidity soundings from the NOAA16 (National Oceanic and Atmospheric Administration) satellite. First, a simulation study is presented wherein a stat...