Research Memo: Upscaling technique

In the HEAPL study, I develop two upscaling techniques; however, for the geostatistical approach, a S/T process is often considered as the combo of a meantrend and residuals. For the upscaling problem, we should be careful of how to apply the upscaling techniques.

It is divided into two parts: meantrend part and residual parts
From the equation (3) and (4) in the HEAPL paper, it upscales the residual meantrend and covariance function into larger scale. As for meantrend part, it is also very important to the estimation, though it is considered as deterministic.

To upscale the meantrend part of the S/T process, instead of the stochastic upscaling as mentioned in (3) and (4), it can be simply aggregated by arithmetic average on the basis of the long-term period.

This idea can not only be applied in this HEAPL study but should be used in any S/T studies.