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AER. TRIANG. WITH AUXILIARY DATA, AUTHOR’S PRESENTATION 101 
ZUSAMMENFASSUNG. 
Dieser Bericht gibt Aufschluss über Fortschritte, die auf dem Gebiete der Luft- 
triangulation mit Hilfsdaten (Statoskop, etc.) seit dem VIII. Internationalen Kongress 
für Photogrammetrie in Stockholm (1956) gemacht wurden. Um diesen Bericht möglichst 
umfassend zu gestalten wurde ein Fragebogen an 21 photogrammetrische Organisationen 
in verschiedenen Ländern verschickt. Von 14 Berichterstattern wurden Antworten er- 
halten. Aus den einzelnen Landesberichten ergibt sich, dass die Lufttriangulation mit 
Hilfsdaten seit 1956 wesentlich an Bedeutung gewonnen hat. Der Gebrauch von neu- 
artigen Hilfsdaten wird zur Zeit studiert, wobei vorallem elektronische Messverfahren 
in Betracht gezogen werden. 
Author's Presentation of the Paper 
Prof A. BRANDENBERGER: From the various 
national reports, it follows that at present a 
great variety of auxiliary data are used in carry- 
ing out aerial triangulation. The variety is so 
great that the following comprehensive summary 
of the various systems or methods of producing 
or using auxiliary data is given. 
a. Aerial triangulation with statoscope and 
altimeters. Statoscopes, radar profile recorders 
and other meters yield air station altitudes or 
air station altitude differences. If these data 
are used in performing a strip triangulation 
they can be converted into bz-values which 
can be used as fixed bz-values in a first 
order stereo plotting instrument — aero-levelling 
method — or as additional information for 
the adjustment of a strip triangulation per- 
formed by the aeropolygon method. When sta- 
toscope or altimeter data are used one has to 
keep in mind that the accuracy of such infor- 
mation depends on the inherent accuracy of the 
instruments being used and the anomalies of the 
isobaric surfaces. The instrumental accuracy of 
statoscopes and altimeters can be determined by 
appropriate tests, while the anomalies of the 
isobaric surfaces and their influences upon air 
station altitudes can be determined only from 
additional meteorological information. If such 
additional information is to be used, a sufficient- 
ly dense network of meteorological stations must 
be available. This requirement might be consid- 
ered as an inconvenience since in many areas on 
the earth there are no meteorological stations 
available, or there is no possibility of obtaining 
meteorological data to correct for anomalies of 
the isobaric surfaces. 
The anomalies of the isobaric surfaces depend 
on the local atmospheric conditions which are 
more or less different from country to country. 
This means that in various areas or countries air 
station altitudes determined from statoscopes 
or altimeters are of different reliability. It has to 
be pointed out, however, that under normal con- 
ditions a remarkably high accuracy for the air 
Archives 5 
station altitudes can be obtained from statoscope 
data. According to experiences in Finland and 
Switzerland, the standard errors for statoscope 
air station altitudes amount to one to two metres. 
Altimeters normally yield a lower accuracy be- 
cause most of these instruments are less sensitive 
than statoscopes. 
b. Another method is the bz = 0 method. Al- 
though this method of strip triangulation does 
not use auxiliary data in a strip sense, the proce- 
dure is very similar to the strip triangulation pro- 
cedure with statoscope data, that is the aerolevel- 
ling procedure. For this reason, it is felt necessary 
to include this method in this subject. When a 
strip triangulation, according to the bz = 0 me- 
thod in a first order stereo plotting instrument is 
performed, it is assumed that all stations have the 
same altitude, that is both bz in the instrument 
are left on zero or are kept constant, and the 
relative orientation is carried out by means of y 
instead of bz. Since the above mentioned as- 
sumption is not normally fulfilled considerable 
lp of the “fixed” camera occur. The real air 
station altitudes are then computed from these 
Ag rotations in a similar way as the statoscope 
errors are determined. With regard to the attain- 
able accuracy for the air station altitudes deter- 
mined in this way, the same considerations hold 
as indicated for the statoscope method. 
c. The third method we have to consider is 
the radar profile method. Experience has shown 
that by means of this method a high accuracy can 
be obtained from relative heights from the air 
stations to ground points on the profile path. This 
accuracy seems to be higher than that which is 
obtained for the relative heights from an aeropo- 
lygon strip triangulation performed in a first 
order stereo plotting instrument. There is no 
doubt that sufficiently accurate distances from 
air stations to profile points which are measured 
by the radar profile recorder represent very 
valuable auxiliary data which can greatly con- 
tribute to stabilise strip triangulations and to 
reduce the excessive error propagation of the