We analyse a CHAMP normal equation matrix. Its eigenvalue decomposition
yields a set of uncorrelated gravity field components ordered by their estimability.
It thus provides illustrative insights into CHAMP’s sensitivity structure: The
best estimable gravity field components show meridional patterns. Near-sectorial
Stokes coefficients generally dominate over other coefficients of the same degrees.
This study may be a starting point for a number of further relevant investiga-
tions also concerning the question of an adequate parametrisation of CHAMP and
GRACE gravity field solutions.