P 
t 
P 
M 
a). Dg = Co-ordinate differences between Py and Puy 
áo 
M 
z Ol 
o 
~U 
we 
b) Aq = Co-ordinate differences between P; and Py 
Ficure 2 
Clarifications regarding the r.m.s. errors according to 
o o o 
the additional computations 
a) relative error derived from the deviations of all the restitutions of a 
flight with respect to the means of the coordinates (R*) 
b) systematic error derived from the means of the coordinates of all the 
restitutions of a flight (S*) 
Explanations: 
P; terrestrially determined point 
Pui, Pu2, ... Pun centres of gravity after figure 1 from various restitutions of a flight 
Py centre of gravity of Py1, Pu2 ... Pun. 
5. Results of the Computing Programme 
The original publication [2] contains, for each restitution, the errors found in accordance with the 
computing programme, presented separately for measurements with analogue instruments and with 
stereocomparators, as well as a summary of the errors pertaining to the individual flights. As far 
as relevant, the errors were moreover grouped in accordance with the point groups (interior, exterior 
and edge points). At the Lisbon congress, provisional values for the absolute and relative errors were 
published (see [1]). 
16