JN Ue eL gl TR, t EM NER TE
z i Ar uae M CLA
puces à ts
da
a
dat Caii niii
aid ia d
,
FERE An
ead d ai
16
f) Poivilliers Stéréotopographe Type B.
The exit pupil E.P. of the projecting camera has to be considered ag centre of nm;
tion. As the projecting lens can be moved to allow for introducing different m
principal distances (range 4,8 mm), the Dotty
instrument has a variable projection cen-
tre, i.e. —2,4 =< e, = +2,4 mm, depending ER
on the plotting principal distance which
has been inserted. Rotation axis
As long as the bundles of rays leaving of telescope o
the projection lens are parallel, the projec-
tion errors are
0X=0x=0
X sd
óY -óy-e;tg-—e,-—
= (11)
V Y24-Z2
If a 9- or better 25-point measurement (10
results in graph 7 it might be due to es. as ii
However, the same, or similar, asymmetry 0
can be due to imperfectly adjusted relais
or Z, oh Z
Since e, is variable, it should be expected that the bundles of rays leaving the m.
jection lens are not always parallel. Hence e, and e, become of importance and Can y
longer be neglected as could be done in equations (11).
Fig. 22.
)
9) Nistri Fotostereografo Mod. Beta/2.
The situation is that of fig. 1 for both the gimbal axis in the projection centre and fy
the gimbal axis in the model point. However, the point B in the projection centre ms
be defined:
Point B is the intersection point of the xy-plane of the gimbal axis system with fl
line connecting
a) the gimbal centre of the model point and
b) the intersection point of the axis of the bar with the support of the bar in the pu
jection centre.
It is obvious that, due to the bending of the horizontal bar, also deviations of the ill
minated floating mark affect the projection errors. That can be treated in a similar wy
as was done above for the Stereoplanigraph. However, the conclusions will be different,
since no comparable part to the cross on the mirror of the Stereoplanigraph is availall
and, furthermore, the illuminated floating mark has no fixed position. We refer to li
literature [2], [3].
The total projection error óX and óY is, if the indices c and b denote errors in t
gimbal axis in the projection centre and in the model point respectively and 0x, 9
stand for the computed displacement of the illuminated mark in the system of the p
jection centre
0X = oxe - 0X + oxb ) (1)
àY = ôye + Sy + öyp |
with öxc, öyc, öxb and öyb from equations (1).
Conclusions:
Besides the errors 0x, and ôyy, à 9- or better 25-point measurement can result in i
graphs 7, 8 or 9. The diagnosis will be errors e;, e; or e, respectively in either one of üt
gimbal axes or in both.
j The Thom)
The exit pt
indicated by 1
and 6, As lont
ie projection
errors are
i-es tg.
jr=dy=0
If a 9- or 2
fig. T (rotatec
, However, 0
symmetry.
As soon as
mjection len
this can be ex
je moved for
md cannot be
References:
[I] 4.J. v. d. V
Photogram
[2] Luigi Ronc
graph, mox
3] Carlo Tron
menti Rest
lisammenfasst
Nachdem r
hat, ergibt sich
fonsfehler seir
im muss, Geg
von Fehlern in
In den Fig.
strahles durch «
märe bzw. sekı
(anebene, wenn
Drehachse para
thene eines Ins
Daraus folgt, d
Gerätes erwarte
Fig. 7 gibt
Drehachse, Fig,
gerufen dadurel
schneidet,
Im folgend
in Effekt von
it Wild A7, Be
Fehler im Spies
