The observables of the GOCE three-axis gradiometer are taken in time, along the orbit and, in the timewise proposal, filtered to stay in the measurement bandwidth, i.e. in the frequency interval between 0.005 and 0.1 Hz. As a consequence, the resulting “observable” is a convolution of the original data stream with a time-wise weighting kernel. In other words, we cannot assume that the observati...