EVALUATING THE ACCURACY OF A GRAVIMETRIC SURVEY 



14a 



of gravity at this point would be equal to g^. It can readily be seen that the 

 error in e of the observed (more accurately, interpolated) value for gravity 

 at the point C is composed of the following two errors: 



« = (S'c - ^c) = iSc - Sc) + i§c - ~Sc) = ^0 + «/' 



where Eq is the error due to observation errors; 



£,• is the error due to the non-hnearity of the field. 



This equation ^vill be justified for any point on the profile. Moreover,, 

 owing to the independence of the signs and the absolute values of the com- 

 ponents Eq and £,- for a multitude of n points on the profile, the following 

 equation will hold 



or 



2 I 2 



(6) 



where e^^ and e,-^ are the mean square errors in the values of gravity at 

 a profile, caused by the corresponding error in the observations and the 

 non-linearity of the field. 



Similar relationships can readily be established for the value d^: 



/S2 = A2 . A2 



(7) 



