Vendredi 19 mars 2021
Esther Eustache (Université de Neuchâtel)
When the sampling population is spatially distributed, selecting close units generates information redundancy.
In order to estimate parameters such as means or totals, it is therefore more efficient to select samples that are well spread out in space.
Often, the interest lies not only in estimating a parameter at one point in time, but rather in estimating it at several points and studying its evolution.
Due to the temporal autocorrelation of successive values from the same unit, a system of temporal rotation of units in the samples must be planned.
We propose the spatial and optimally temporal sampling (spot) method that can be used to select samples with fixed size and well spatially spread at each sampling time.
A particularity of this methods is the use of the systematic sampling to provide an optimal time rotation of the selection of the same unit in longitudinal samples.