/ummnated
e//oobing mark.
ors With respet i
mark, which hag,
Oy obtained vla
ro|
ee.
— sin 50
jute a table of t
The final projets
13
Cimbal axis in projection centre (auxiliary system).
y, Gi
The situation is given in fig. 14, if the cross K is replaced by the excit pupil of the
diary system. The derivation of a formula for the projection errors dx¢ and öyc gives
al
tions (1). d
pe total projection error is then (the errors in the projection centre are not (n+ 1)
enlarged into the projection plane in instruments with optical projection, as the
4 of rays leaving the projection lens are parallel):
dX = ôxe + Xp i
dY = dye + ôy, i (8)
time
pond]
Note: Errors in the gimbal axis of the Stereoplanigraph have been determined by
à Weele [1]. Nowadays, the factory adjusts the eccentricities in both gimbal axes with
v d.
mean Square error my; = — 4 u.
Conclusions:
Due to the relation between the cross and the illuminated floating mark, it is pos-
sile to separate in the Stereoplanigraph errors in the gimbal axes in thc auxiliary system
tom the ones in the mirror. Any error in the mirror-gimbal axis causes a 0z-displacement
i the cross with respect to the illuminated floating mark, as can be seen from equation
(ie) (this 0z appears in the observation system, of course, as an x-displacement). Further-
pie an error e, causes a dy-displacement of the cross. The gimbal axis of the mirror is
free of errors if careful
check shows no displa-
cement of the cross with
respect to the illumin-
ated floating mark,
provided that the illu-
minated floating mark
has been centered onto
the cross in the position
a=f=0.
If a 9- or better a 25-
point measurement re-
sults in fig. 7, 8 or 9,
the diagnosis will be er.
rors e., €, Or e, respec-
tively of the gimbal
axis in the projection
centre.
AES
|
d) Santonis
| [d
; P | Stereocartografo IV
/ | , | F
and Stereosimplex.
A ball and socket joint
is used above the pro-
jection centre. The principle is given in
Projectson bor. | The ball joint is determined by the
| | points A, C and D. Requirement is that
| | both the big ball with radius r, — r, as
i | | well as the small ball (cam) with radius
Fig. 19 | r, have M as common centre and that
rer
=
4
3
3
j
ES
ES