- 27 
e basis of available 
:curacy to be achieved 
nd to perform aerial 
ope data and APR data 
le surveys and mapping, 
control of up to 60 to 
lS far as the accuracy 
, or which is inherent 
~y data the following 
ghts determined by 
000 ft which is theair- 
, 000 sq. miles in Aden 
a RC 6 A spotting ca - 
\.PR lines beginning at 
ormula corrections 
and Protectorate and 
e horizon on the hori- 
s Surveys : An area of 
• strip) and 3 tie strips 
;rval 20 ft). The maxi- 
linst control heights 
ice is made to " Char- 
e area of 40, 000 sq.mi. 
orth-South strips (75 
d statoscope control- 
•ol extended across 
itervals. The adjust - 
mputer. The maximum 
were less than 20 m. 
sal surveys were per- 
it 1 /4 mile apart with 
Lentation yielded apla- 
are being performed 
statoscope and a Wild 
4 mm focal length. It 
lospheric conditions 
regard to required 
i is available. Hun - 
/4 hours (exclusive 
hese times are about 
dliary data is not 
il triangulation with 
ings Surveys (see 
ue to a dense natio- 
vt intervals of appr. 
der traverse net - 
he required accura 
cy of aerial triangulation in Japan is determined by a standard error of less than t 2 mit is felt 
that the additional use of auxiliary data is ineffective. 
South Africa : 
Presently the statoscope is used to perform aerial triangulation with auxiliary data in 
connection with ground control determination for mapping in medium scales (1: 36,000, 1:50,000) 
and small scales (1 : 75, 000 and 1 : 250, 000). In principle, aerial triangulation with statoscope 
data is only used in remote and partially developed areas. For 1 : 50, 000 mapping the statos - 
cope data are directly introduced as pre-determined bz-values into the Wild Autograph A7 or 
A9. For the 1 : 250, 000 mapping experiments have been conducted in hanging the strip triangu 
lation on the statoscope data using Wild RC 9 superwide angle photography in the Wild Autograph 
A9. - It is felt that in parts of the country which are well served with Geodetic Control, auxi 
liary data will not be used, but in the more remote areas where Geodetic Control is very spar 
se or non-existant, assistance of the use of auxiliary data is necessary. The statoscope data is 
used at present because it is easily operated and economic to obtain. Other auxiliary data equip 
ment which may be considered for future use are the A. P. R., Horizon Camera and Aerodist. 
Particularly the Horizon Camera is favored being less expensive and less delicate than the A. 
P. R. and as heights are required for mapping it is doubtful whether the Aerodist would be used. 
Rather Tellurometer traverses might be used to determine ground control. - For the perfor - 
mance of aerial triangulation with statoscope data (strip triangulation) the well-known conven 
tional aeroleveling method is used at the Wild Autographs A5, A7, and A9. No analytical pro - 
cedures are in use. - For the performance of strip triangulation with auxiliary data sufficient 
ground control is given in the first model and every 12 th model of the strip. Strip adjustment 
is performed semi-graphically, but the adjustment using electronic computation is being deve 
loped. For the strip adjustment the statoscope data is inserted as a mean curve into the hig - 
hest adjustment curve. The application of this procedure to an electronic computer adjustment 
procedure has still to be developed. No block adjustment procedure is used. - To determine 
the accuracy attainable with strip triangulation with statoscope data two tests were performed ; 
Test 1 : 38 models, photo scale 1 : 36, 000 (h = 5 400 m), Wild RC 5a camera, given ground 
control at both ends and in the middle of the strip, standard residual horizontal error Mp =t 9 ft 
= t 2.7 m, standard residual vertical error M = 1 5. 5 ft = t 1. 65 m. Test 2 : 33 models, pho 
to scale 1 : 75, 000, (h = 6 600 m), Wild RC 9 Camera, given ground control at both ends and in 
the middle of the strip, M = * 20 ft = t 6 m, = + 7 ft = + 2. 1 m. - As an average 5 models 
per day are triangulated at the instrument and 9 models per day are adjusted. It is anticipated 
that the adjustment time will be reduced when electronic computer adjustment will be used. - 
No reliable information is available on required costs for aerial triangulation performed using 
auxiliary data and no comparison is possible with ground surveying methods since these me 
thods were stopped in 1936. 
Spain : 
In general no auxiliary data is used in this country with exception of a flight mission 
performed in the Sahara by the Instituto Geografico y Cadastral using the Wild RC 9 camera and 
Doppler for control of parallelity of flight lines and sidelap. 
Sweden : 
In general aerial triangulation with auxiliary data is not used in this country. However 
tests have been made at the Institute for Photogrammetry of the Royal Institute of Technology 
(Prof. B. Hallert) to determine the accuracy of tilt determination from horizon pictures taken 
with the Wild HC 1 horizon camera in connection with a Wild f = 15 3 mm Aviogon film camera 
in Northern Finnland (three strips). The test was performed by taking the difference between 
(o and 9 values obtained from the horizon camera and the corresponding values obtained from 
setting up the models in a well-adjusted Wild Stereoplotter A8 by means of a sufficient number 
of given ground control points. Under proper consideration of the inherent accuracy of the tes 
ting procedure the standard errors of the lateral and longitudinal tilts o and 9 respectively we 
re determined and found to have a value of appr. 2 C . In this test which was performed by Dr. A. 
Leijinhufvud attention had to be paid to the real location of the horizon with respect to the flight