EIGEN-2

CHAMP-only Earth Gravity Field Model derived from altogether six months of CHAMP data

EIGEN-2 Gravity Anomalies (a=6378136.46, 1/f=298.25765) in mgal

EIGEN-2 Geoid (a=6378136.46, 1/f=298.25765) in meter

EIGEN-2 is a CHAMP-only gravity field model derived from CHAMP GPS satellite-to-satellite and accelerometer data out of the period 2000, July to December, and 2001, September to December.

Please note: although higher-degree/order terms are solved in EIGEN-2, the solution has full power only up to about degree/order 40 due to signal attenuation in the satellite's altitude. Higher degree/order terms are solvable applying regularization of the normal equation system. The accuracy of EIGEN-2 is well below 10 cm and 0.5 mgal in terms of geoid heights and gravity anomalies, respectively, at lamda/2=550 km.

The EIGEN-2 solution:

• fully normalized spherical harmonic coefficients complete to degree/order 120 plus selected terms for CHAMP sensitive and resonant orders up to degree 140.
• permanent tide is not included in C(2,0)
• C(0,0) and degree 1 terms are not solved for
• standard deviations (as resulting from the adjustment) are given along with the coefficients
• the EIGEN-2 correlation matrix of the spherical harmonic coefficients is available as a CHAMP OG Level 4 product through the Information System and Data Centre (ISDC).
• the formats are described on the CHAMP web pages (www.gfz-potsdam.de/champ) under References & More 'Online Available Documents in the document' 'CHAMP gravity field solution data formats'.

The EIGEN-2 solution should be referenced as:

Reigber, Ch., Schwintzer, P., Neumayer, K.-H., Barthelmes, F., König, R., Förste, Ch., Balmino, G., Biancale, R., Lemoine, J.-M., Loyer, S., Bruinsma, S., Perosanz, F., Fayard, T.: The CHAMP-only Earth Gravity Field Model EIGEN-2. Advances in Space Research 31(8), 1883-1888, 2003 (doi: 10.1016/S0273--1177(03)00162-5)