Σάββατο 13 Απριλίου 2013

The minimum sample size for kriging


September 17, 2011    Posted by karmadsen under blog, Geostatistics, Modeling Software, Statistics      
2 Comments
In attempting to find a rule of thumb for the minimum number of observation points needed for kriging, I found out that it’s not particularly straightforward.  Kriging is a linear least squares estimation algorithm. Even in simple least square regression there is a lot of guess work involved in determining the minimum sample size needed prior to conducting a study.  Various estimation methods exists to help researchers design regression analysis studies based on the number of variables and the the desired power level.  But in kriging, there are added levels of complexity.  The x,y distribution of points matters (i.e. they shouldn’t all be clumped together).  The volatility of the z-value matters (i.e. you need more points to capture busy spatial trends).