Distance between dots should be uniform in the field measurement. Sampling number should be estimated by certain believe level, estimate accuracy and variance coefficient.
田间测墒时，点与点之间的距离要均匀，取样数目可以根据一定的置信水平、估值精度、变异系数做估算。
2
A granite platform (Granite Flat Panel) was a long-term natural aging, organizational structure, uniform, linear expansion coefficient is extremely small, internal stress disappear, not deformed.
花岗石平台（花岗石平板）经长期天然时效，组织结构均匀，线胀系数极小，内应力完全消失，不变形。
3
The optimization design for guidance parameter and coefficient is carried out by using uniform experimental design method, and the effect is prommet.