-10- 
a reasonable intersection of the two or more distances measured. 
r 
Shoran, which can be used for measuring distances of up to 600 Kms, has an 
attainable accuracy of +_ 4 ni. 
Aerodist results in a higher accuracy (+1 m); it can however only be used 
for distances of up to 200 Km« 
Shiran is also a part of the ANQ-28 system, allowing in combination with 
"the inertial platform, the direct determination of the plane co-ordinates 
of isolated ground points from the air«, 
The main field of application of this equipment will however be in airborne 
trilateration by line crossing methods«, 
Doppler 
Doppler equipment, based on the principle of continuous integration of the 
incremental movements of the aircraft (determined by the application of the 
radar principle), has also been applied as auxiliary data to aerial triangu- 
lation. In this case, the distance between consecutive exposure stations is 
registered and used to control the scale of individual models. 
As, however, the standard deviation of these data has been evaluated as 
about 0.25*}° of the time/distance, the application of this equipment should 
be restricted to special projects with very low accuracy requirements, or 
merely used as a flight navigation aid«, 
III. General application of auxiliary data 
The possible applications of auxiliary data to photogrammetric projects are 
illustrated in the following scheme. 
The first two types of application are actually beyond the scope of this 
paper, but will be treated briefly in order to improve the general under 
standing of the subject«,