Prior to going into detail, it is perhaps worthwhile to review the objective and to summarize
the approach to be taken. The overall problem (shown in Fig. 3.75) is that of assigning a
grade go to the point xq knowing the grades g,- at surrounding points x,-.
The objective can be simply expressed as that of determining coefficients a,-'s which
when multiplied by the known grades g,- and the resulting products summed will yield a best
estimate of the grade go - The equation developed is called a linear estimator and has the form