236 



M. N. Berdichevskii 



where: Eq, is the tangential component of the field of the feed line A' B' 

 E^ is the tangential component of the field of the feed line AB. 

 Thus, 



E& 



Ee 



1 100%. 



(20) 



Eq' 



In agreement with the previously derived formulae we obtain 

 sin {0+ y) 



ABV , AB ^^ ^ 



2R +l + ^-s(0+y) 



f-3 

 2 



+ 



sm 







ABV ^ AB 



__ Ul+-^cos0 



t-z 



2 



+ 



ABV -, AB 



2R +i-ir^^^^ 



is 

 2 ^ 



sin 



ABV ^ AB „ 



t-3 f-3 • 



^ ^^ABY , AB 



(21) 



+ 



+ 1 — =^cos6> 



Mj +'-ll 



The results of the calculations for v, obtained from formulae (20) and 

 (21), are given in Table 3. As can be seen, with an angle 0, within the range 

 from 70 to 110°, and a length of feed line up to 0.6 R the angular errors 7, 

 reaching 2°, lead to errors in KS not exceeding 2%. 



THE PRACTICAL PROCEDURE FOR AZIMUTHAL PROBING 



The work of experimental parties of VNIIGeofizika made it possible to 

 develop with sufficient completeness a method for azimuthal probes and 

 showed the effectiveness of the described method for measurements under 

 conditions involving difficult transport. 



The azimuthal probes w-ere conducted with the ERS-23 electrical survey 

 station, which included two field laboratories, mounted on the GAZ-63 

 vehicle. The probing profiles were curved roads, not particularly suitable 

 for vehicles. Initially, the topographical surveyors marked out the curb of the 

 road into 100 m spacings. The plan of the markings was entered on to 

 a plane-table grid on a scale 1 : 25,000. The markings were fastened with 

 standard pegs carrying the number of the profile and the peg number. 

 Near the pegs there were high m.ounds which were easily recognizable in the 



