4 
zontal nets are built up from the photos of the main strips, photogrammetric and radio- 
geodetic coordinates being adjusted simultaneously. 
It should be clear that the same lines may be followed in executing larger scale 
mapping; but if simultaneous adjustment is carried out the weights assigned to values 
obtained by direct methods are to be correspondingly lowered, since as the altitude of 
flying decreases the accuracy of photogrammetric measurements is improved.