More Accurate and Faster Available CHAMP and GRACE Gravity Fields for the User Community

CHAMP and GRACE gravity field models are based on satellite-to-satellite tracking in high-low and, in the case of GRACE, low-low mode. The products derived from exploitation of these instrument data showed already a quantum leap compared to models derived at the end of last century. But, especially for GRACE, the gravity fields did not reach the accuracy predicted before launch. Also the CHAMP models did not show long-wavelength time-variable gravity field signals, except for the very low degrees. Therefore several algorithms and methods applied during gravity field determination process have been improved and new CHAMP and GRACE EIGEN (European Improved Gravity field of the Earth by New techniques) satellite-only static and time-variable as well as high resolution combination models have been derived. Additionally, so called “base products” necessary for other CHAMP and GRACE mission experiments, such as the Rapid Science Orbits (RSO) for radio occultation or magnetic field data analysis or Satellite Laser Ranging (SLR) orbit predictions as support to the International Laser Ranging Service (ILRS) have been improved in terms of accuracy and submission time to users. All products are available at the Information System and Data Center (ISDC) which has been completely redesigned. The overall high interest in CHAMP and GRACE products is manifested in nearly 2000 registered ISDC users.