- 23 
¡.angulation with au - 
>r orientation ele - 
ent time nearly ex - 
is made between the 
method yields only 
auxiliary data can 
aerial triangulation 
-altitude photogra - 
h principal strips (tie 
ary data. In the first 
uch strip triangula - 
’iangulation and ae - 
rst order stereoins - 
ype B, Santoni Ste - 
i Autograph A9, 
nstruments (Wild 
of analytical aerial 
, Hilger and Watts 
Mod. ТАЗ, SOM 
arator, Zeiss Aero- 
;ed computers. Basi- 
jment stage and on - 
Iready put in prac - 
ngulation is under 
terial triangulation 
ical plotters auxilia- 
lation is to deter - 
)se of reducing the 
this endeavour is 
3 by airborne me - 
le tedious, time and 
clearly demonstra- 
togrammetric map - 
luce ground surve - 
ble ground control 
1 percent of the 
•it. 
used for the perfor- 
osure stations of 
an or in the near fu- 
lotography used for 
used for aerial tri- 
4 Recorded swing x (bearing) of aerial photography used for aerial triangulation by various 
systems presently under development. 
It is obvious that the determination of most of these orientation elements would be un 
necessary if completely vertical photography could be provided for and if automatic navigation 
systems would keep the survey airplane with sufficient accuracy on the prescribed flight lines 
horizontally as well as vertically. It appears that the most recent development programs of the 
U. S. Air Force point toward this trend. 
PROGRESS REPORT ON AERIAL TRIANGULATION WITH AUXILIARY DATA 
IN VARIOUS COUNTRIES 
Au stria : 
No auxiliary data are used to perform aerial triangulation. 
Burma : 
No auxiliary data are used or are considered to be used to perform aerial triangulation. 
Canada : 
The Topographic Survey of the Canadian Department of Mines and Technical Surveys 
is successfully employing the aerodist to establish control in areas where traditional methods 
are not practical. Basic control is being extended by trilateration using the line crossing tech 
nique. Aerodist controlled photography is being used to control blocks of 1 : 50, 000 scale map 
ping. The survey aircraft is fixed at the instant of exposure by ranges measured to three ground 
stations at distances up to 100 miles. A similar photo fixing technique is being used to provide 
a block coverage over water where shoals and offshore islands exist. No accuracy information 
is available. Canadian Aero Service, Ltd., has used a Wild horizon camera to extend control 
over some 4, 000 square miles in the Athabasca area. This project consisted of eight flight li 
nes approximately 100 miles long comprising 40 stereo models on each line (Wild RC-9 photo 
graphy, photo scale 1 : 50, 000). The strip triangulations were performed at the Wild B8 Plot 
ter, and the strip adjustment was done using control only at both ends of the strip. Closure er 
rors before strip adjustment of only 7 to 67 feet were obtained. The subsequent block adjust 
ment yielded an accuracy sufficient for 50 foot contour lines. Auxiliary data were also used in 
a 37, 000 square mile mapping project in Nigeria (1 : 50, 000 scale mapping with 50 foot contour 
interval). To control the Wild RC 9 aerial photography (photo scale 1 : 40, 000) the Radan Dop 
pler navigation system, and the Wild horizon camera and statoscope were used. The accuracy 
of the tilts co and 9 obtained from horizon photography was tested by establishing the absolute 
orientation of models at the B8 using given ground control, and the following standard errors 
were found : m ^ = + 6 C , m<p = 1 4 C (35 and 30 comparisons, respectively). In a similar way the 
accuracy of the statoscope data was tested by determining the error of the longitudinal tilt 0 
obtained from the statoscope exposure station altitude differences in various models, and the 
following standard error was found : m^ = + 7 C (19 comparisons). Each strip was adjusted se 
parately utilizing vertical control at the beiginning and at the end (at 15 model intervals). The 
residual vertical errors after block adjustment based on 97 vertical test points spread through 
out the test area are as follows : 
87 per cent within + 10' (1/5 of the contour interval) 
92 per cent within + 12. 5’ (1 /4 of the contour interval) 
98 per cent within t 16. 5’ (1 /3 of the contour interval) 
For more information of this aerial triangulation project reference is made to : J. M. 
Zarzycki : " New Aerial Triangulation Techniques Employed on a Mapping Project in Nigeria ", 
Photogrammetric Engineering, July, 1963 [9]. 
It is conceivable that research on aerial triangulation with auxiliary data was also per