1. Method for determining a spatial quality index of regionalised data and intended for determining a priori anomalistic data and accordingly assess the quality of the measurements or of the digital processing which have generated said data, comprising the following operational phases: a first phase for identifying the first order statistical anomalies from a set of raw regionalised data, this identification including a rendering said data stationary by a preliminary extraction of the spatial drifts of said data and the determination of the associated first order stationary residue so that the value of the average of the residual data is reasonably constant in space, the anomalies being identified and examined on the first order residue so as to provide a first order anomaly criterion, a second phase for identifying the second order statistical anomalies with extraction of the components of first order residue regarded as anomalistic and components of first order residue regarded as coherent in space, setting up a quantified relation between any combination of the estimated values of the anomalistic components of the first and/or second order and any combination of the estimated values of the coherent components of the first and/or second order.