Grid Spacing

Gpc data collected from a previous drop test, which used a grid with cups in a 10- by 10-foot spacing, were used for the following comparisons. The 10- by 10-foot spacing provided a data set that could be divided into subsets for cross validation. Two subsets were created with the points in a 20- by 10-foot spacing, and three subsets were created with the points in a 30- by 10- foot spacing. Figures 22 and 23 show examples of these subsets. Tables 10 to 14 display the cross validation tabular results. Figures 24 and 25 display the QQ-plots comparing distributions.

Figure 22—The original 10-foot spacing was increased to 20 feet to
evaluate sampling density.

Figure 23—The original 10-foot spacing was increased to 30 feet to
evaluate sampling density.