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4. In addition to relative simplicity and high accuracy, the method has important ıl 
a 
  
    
First, the elevations were adjusted in the way described. The lon 
adjusted linearly since the poor quality of infrared oblique PEORES i: Bit y, 
of horizon measurements. "a alloy 
In the bridging, about 200 vertical control points were include 
centrated mostly in the central portion of the strip. The closure error in 
was approximately 4-60 m. The mean square error in elev 
on the use of the radar profile is: 
d. 
There Wee y. 
^ 
4 before adj 
: stes 
ation after an à djustme Mai 
nt has 
m, = t2. m. 
The distribution of errors is shown in Fig. 4. 
It is evident that the accuracy of elevation points situated far away from the y 
line is smaller than the accuracy of axial points. Taking into account only oe 
situated up to 1 km on both sides from the nadir line, the accuracy wil he FR 
m, = *1.8 m. 
The construction of the straight line was very difficult because of the exceptions] 
poor quality of the oblique photographs. After adjustment for the transverse] C 
the strip the machine coordinates were transformed to the geodetic system using one 
at the beginning and one point at the end of the strip. Only linear scale adjustment v; 
applied. The coordinates were corrected for the map projection used, in our ed 
yt 
  
Transversal Mercator Projection. There were spread along the Strip 47 available gun 
control points for the computation of mean square errors in x and y eoordinates, e 
amounted to: 
m= +6.4m, 
MM, = =80m. 
Fig. 5 shows errors in z, x and y after adjustment. 
, J 
Conclusions and remarks. 
1. The distances bridged and accuracies achieved in experiments with airborne contri 
aerial triangulation method are unprecedented. 
2. General efficiency of the method will be increased by the use of especially desig 
straight line plotter for the construction of a control line throughout the infu 
oblique photographs and by the analytical treatment of the method. The adaptatin 
the bridging procedure to analytical treatment is under way. 
9. At present time, the construction and computation of a “straight line” from oblige 
photographs is an operation which requires about one week of work for one pet 
bridge about 90 models. This is assuming that the oblique photographs are of an avg 
quality. 
vantages: 
All required auxiliary elements are secured from the plane during the usual plo} 
graphic flights. 
The method does not require establishment of any field station. : 
The method is not very sensitive to the usual mistakes or local errors oi tt 
triangulation which can affect over-all accuracy. 
The high accuracy of the radar profile elevations is limited to certain points mj. t 
the contrary the elevation accuracy produced by aerial triangulation does not dt 
upon the type of points used. Therefore even in reference to the elevation ponts d 
the aerial triangulation cannot be simply replaced at present time by the stg: 
APR data. 
  
  
    
   
   
   
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