152 



B. V. KOTLIAREVSKII 



The relationship (26) can be represented approximately (with an error 

 <8%) also in the following form: 



1.167 



P' 



From formulae (17) and (20) 





6q 



2^4 A 



'10 



-1 



p 



p 



A., 



Finally, substituting in the equation (8) the values E^ 

 formulae (22) and (23), we obtain 



om and £',.„, from 



0.075a* +1.5 



In the same way, substituting in equation (9) the values Dq^ and D^^ from 

 the formulae (24) and (25) or (26) and (28), we obtain: 

 for the case </> < ^lo 



Z)2 = 



go'a^ 



'10 



1- 



A., 



+ 



^10 



A 



10 



for the case ZIjq </> < 2 A 



10 



2^4 



r,2 _S£^ 



J-'m n An 



'10 



'10 



P 





3p^ 



Ji 



A 



10 



(30) 



(31) 



In all the formulae, a is given in fractions of Iq. 



The formulae (29) and (30) or (31) are the most general. They establish 

 the dependence between the seven variable values: the elements of the 

 field (g'o, Zo), the parameters of the survey (o, a,p) and the indices of the 

 relative accuracy of the map (£'^ , D^^). Knomng any five of them, it is possible 

 to find the other two. The most typical in practice can be the following 

 cases. 



1. The elements of the field {gQ, Iq) and all the parameters of the survey 

 (a, a, p) are given. It is required to find the indices of accuracy {E^ and D^ 

 of the survey. 



2. The elements of the field {g^, Iq), the indices of accuracy of the work 

 (E^, D^) and the value a are given. It is required to find the network 

 density a and the cross-section of the isoanomalies p of the planned survey. 



3. The values gQ, Iq, E^, D^ and/> are given. It is required to determine 

 the network density a of the planned investigation and the accuracy of the 

 values of gravity at the consecutive points of observation a. 



