Global gravity field models have been determined based on kinematic orbits covering an observation period of two years beginning from March 2002. Three different models have been derived up to a maximum degree of n=90 of a spherical harmonic expansion of the gravitational potential. One version, ITG-CHAMP02E, has been regularized beginning from degree n=40 upwards, based on the potential coefficients of the gravity field model EGM96. A second model, ITGCHAMP02K, has been determined based on Kaula’s rule of thumb, also beginning from degree n=40. A third version, ITGCHAMP02S, has been determined without regularization at all. The physical model of the gravity field recovery technique is based on Newton’s equation of motion, formulated as a boundary value problem in the form of a Fredholm type integral equation and corresponds to the model which has been used for the recently published models ITG-CHAMP01S, 01E and 01K. The observation equations are formulated in space domain by dividing the two-year orbit into short pieces of approximately 30-minute arcs. For every short arc, a variance factor has been determined by an iterative computation procedure. The three new gravity field models have been compared to the one-year solutions ITG-CHAMP01 and to a superior GRACE solution GGM01s. It shows that the two-years observation period has a remarkable influence on the satellite-only solution ITGCHAMP02S, when compared to the results based on an observation period of only one year, ITG-CHAMP01S. There is still an improvement in case of 02K while in case of the EGM96regularized solution 02E the degree variances do not show additional improvements compared to the corresponding one-year solution. Citation. Mayer-Gurr, T., Ilk, K.H., Eicker, A.: ITGChamp02: An Improved Gravity Field Model from a Two-Year Observation Period, CHAMP/GRACE Science Team Meeting 2004, published online, www.gfz-potsdam.de/pb1/JCG, 2005 Correspondence to: T. Mayer-Gurr (tmg@ geod.uni-bonn.de)
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)