8 
The remaining parameters are obtained by means of identic systems, where 
Cy, b and c come in substitution of Cx, a and d. 
The calculation of the corrections for each point is then effectuated by means 
of the general expressions and the respective Xp and Yp are previonsly cal 
culated. After affecting the coordinates by these corrections the transformation 
into ground coordinates is made, which is inverse of that effectuated with the 
initial Helmert. 
2.2.3 — STRIPS WITH AN INTERMEDIARY CONTROL, ADJUSTED BY 
MEANS OF A 3 d DEGREE EXPRESSION 
It was still programmed, for the case of one single intermediary control, the 
adjustment by means of a 3 d degree expression. In this case the coeficients of 
the X and Y corrections expressions result from the integration of the 2 d degree 
terms of the correction expressions of the error of scale and azimuth (respectively 
c2 d2 x 
and — 
3 
3 
In the actual form of the programme, considered as experimental, this procedure 
is effectuated simultaneously as it is shown in 2.2.2 making the out-put of the two 
results. 
Various adjusted sets were already analised. The absolute errors of each strip 
were calculated by the method indicated by Dr. Brandenberger in his publication 
«Practise of aerial triangulation». 
The mean square errors obtained from four profiles with a total of 56 analised 
strips were: 
2 d degree — X= +21,1 m 
Y= + 14,4 m 
3 d degree — X= + 18,8 m 
Y= ± 9,0 m 
The analised strips had about 110km of length and the flying height over the 
ground was 6000 m. The performed profiles were situated at the mean distance 
between the controls. 
In this case the expressions used for the adjustment are. 
Cx — 
3 
Xp 3 + e2 Xp 2 + e\ Xp+ {d2 Xp 2 + d\ Xp). Yp