ON STATIONARY PROCESSES IN THE PLANE

The sampling theory of stationary processes in space is not completely analogous to that of stationary time series, due to the fact that the variate of a time series is influenced only by past values, while for a spatial process dependence extends in all directions. This point is elaborated in ?? 2-4. The estimation and test theory developed in ? 7 is applied in ? 8 to uniformity data for wheat and oranges. The final section is devoted to an examination of some particular two-dimensional processes.