ARCGICE WP 2.1 Leader: DSPC Make new geoid of afrctic region based on GRACE C.C.Tscherning, University of Copenhagen,

Observations: Parameter is equal to N 0 mean sea surface height A i = 1 if bias only for all values of i which are associated with geoid heights. Parameter and error-estimation C.C.Tscherning, University of Copenhagen,

Then an estimate of T and of the parameters X are obtained as where W is the a-priori weight matrix for the parameters (Generally the zero matrix). Parameter estimate C.C.Tscherning, University of Copenhagen,

Data may be gridded, so that spherical FFT can be used. (GEOCOL). Data gridding C.C.Tscherning, University of Copenhagen,