1
usual
bration showed real
means of a series
it was more a
results, mean errors
1 ... 2 urn.
measurements we found out that
instabil
than of
else.
of the tests
2 .. 1
The stability
was started in 1984 .. Since then seven test
sets of one to two weeks have been carried out with our Kern
DSR- .. In order to
the stabil
of
, the other five instruments were taken with
in 1986 Their
lasted one week each, that is
with different combinations of variables
the test set
should have been
in order
clearer conclusions of the results, but instruments in
can
be taken off
from their every
use
e
In order to
e
measured every
coordinates of several
are
with different
half an hour over a time of one
an affect to the
combinations of variables
was to observe the coerinstabil
The
dinates of each
and
interest over the test set
to follow how
of
we measured were
ates
since there was some doubt that the
the movement of
ates with four
al marks for
At
sion
fiducial
In order to have a good
was measured five
times
so that
automatical
and
moved away from
of
After these five
the coordinates and the mean errors
were
As a criterium for
and
the
mean of the five
the
deviation had to be
less than 1.5 urn.
The measurements were done both
and
order to see if direction of movement had any
results ..
One
test
in
the
set
consisted of individual tests 1
that is 8 hours, to two or even
minutes
coordinate measurements were done in every
the first two hours after
the power on and
thereafter in every
minutes ..
As in
work the
carriers are
most of the
time, it was decided to test if this had any influence on the
results.. So the
carriers were either not
at all
1
between two successive measurement times, or
tical
from a
to the fol
one,
there for two seconds and then
to the next
on in a
over the
minutes
The DSR-1 has an
with function buttons and a
just in front of the instrument.
The operof luminous material and
very hot
to
To
if it had any influence to the
some tests were done with both the P3 and the
switched off in HUT.
one week,
recorded .. Also
was
inside the Kern DSR-1
of nine different
were recorded with calibrated sensors ..
seen that
It was
the
but
inside the instrument varied in time
between different
the difference at the same time was
never more than 1 .. 5 oc
short, the variables used in
were
order of the
- duration of the test
movement of the
carriers and
on or off (
in DSR-1) ..
2.2 Instruments used in the tests
We used
instruments in the
Kern DSR- of the HUT,
another Kern DSR- in Hel
Finland
- Wild BC-2 in
, Finland,
- Kern DSR-llB in Karlsruhe,
- a
version Kern DSR-11(with linear
encoders and large
carriers) at the
Kern in Aarau, Switzerland, and
Pl
in
FRG ..
of
some of the test series were
because
of failures in the
or in the
, but even then
one could
an idea about the stabil
the instrument ..
Also, it is to be noted that in these tests
was not
the same person but the
situation was tried to
made as similar as
error of the five
less than
same size of
mark as also of
3
In every tested instrument some kind of instabil
was to be
found.
There were
coordinates
the first hour
as
as ater
are less
2 urn it can
as noise,
usual
were between
times and over the
to 5 urn and from 3 to 0 urn,
instrument was
di
and therefor it would
not be justified to compare the instruments
with each
other, and also
the
for each instrument
was so short
General
can be said that the behavior of the instrument in
four coordinate axes differ from each other.. E .. g.. in one
the maximum difference was about 3 urn over the whole
in the another one the difference was
to a difference of about 10 urn.
In the fol
the results are
factors found to effect
to the most
Time
It is
seen that in most cases
is
not stabilized in 15 . 30 minutes after
power on,
like manufacturers
The
usual
take
ace
the first
and
settle down a bit,
after six hours
can occur a
on and on ..
often on the fol
after power on in the
but
carriers not
coordinates are not usual
the
same as on the
can be of order of 3 ... 7
urn
In case
next
, one should
remeasure some
to see if the
in coordinates can be
difference if
carriers have been
if
have
one
The time
the coordinates is different to each
one should let the instrument
carriers move at least 1 ...... 1, 5 hours
on. And if the
carriers have not
, one
wait for about
5 ...... 2 hours before
measure the coordinates. (
1. )
In
repeated tests with movement of
carriers between
times, the behavior of the instrument was very similar
each axis and in different
of the
carrier..
But
when
those results to the ones when the
carriers
had been in one
(not
between the measurement times),
the behavior of the coordinates was very much different..
That
is most 1
due to the
effect of the movement to the
carriers or to the
(
2. and 3.
The direction of
the axis does not seem to make any
difference ..
clockwise and anticlockwise does not have
any remarkable influence on the coordinates in any instrument
4
and 5.. )
" (
i
f
the
stabil
of
To
an
, the first results of
the Kern DSR-1 at HUT in 1
showed
as 12 urn differences
in one of the coordinates between
successive measurement
times and very often there were
crescent
in
the coordi ates dur
the
e
ing peri
n the
insulation was made more efficient new ventilators
were installed and electrical wires were
, one could see
a
in the stabil
The effect of
is also to be found in the results of
the tests with the P3
The
are more
axes when the P3 is off than with the P3 on.
Further, when
one could see
cases the room
that
in one
the
Test results show that the
coordinates with time
non-linear and of
upon the
the measured
ass
ate ..
effect should
like a scale factor but
that is not to be seen in the results, at least not
(
6 .. )
with linear encoders the
in coordinates
seem to be less or more
in instruments with
When we started
these tests with the DSR-1 in 19
sometimes there
jumps',
10 to
urn in one of the coordinates between two
measurement
times (
difference of
minutes). That is very difficult to
otherwise than as
hardware or in
of
In the Kern DSR-1 tests
to see if there are
ses 'lost' when
carriers
However, the results did not
show it to
. When
the Zeiss Pl
there also
similar kind of effect without any
in the test
situation
4
We
were
to see that the stabilities of
are not what one could
results
of calibrations or to the statements of the manufacturers and
users
work when
coordinates
of new
the stabil
if
the
It is
micrometers
accuracy.
The results
above are
the first results and
will
ished later Also, it
be
that the
and the numbers are
material of more than 100 tests. What should be
that based on these tests, it is still not easy to draw
conclusions of the reasons of the found
lities
several
are taken into account, it is difficult to
all the
influences from each other. Much more
difficult, if not
it is to find a linear model to
correct these
lities.
More tests also with new kind of
factors should be taken into the
before one
could
define the model of the stabil
of an
5.
thanks to Mr
Jan
The authors want to express their
Heikkila for all his
work in the course of the
ect ..
/1/ Jaksic,
z.
Makarovic
B ..
uc-r-r''l::l",
L .. H..
Evaluation of Functional
Characteristics of
and Structural
Plotters. ISPRS
for Evaluation of
Commission II WG 1
Procedures
ters .. ISPRS
for
, Rio de Janeiro, 1984.
the differences in the four
the
d
of the
drawn in
picture.. Also the maximum
differences in each axis are
MAXIMUM DIFFERENCES
1
2
6.0
4.0
dx left:
5.0
3.0
dx left:
right:
dx right:
dx
10.0
9.0
9.0
5.0
5
DX 1 ~fjt
DY ltft
MEAN DIFFERENCES
2
3
1
3.0
1.7
-2.2
3
6.0
5.0
10.0
4.0
1)
2)
3)
COORDINATE
DIFFERENCES (UM)
are
ate is
and mean
.9
1.7
1.3
-2.7
-5.0
-7.1
-.8
.0
-2.5
after time 0
between 2 successive measurements
after 1/2 hour
--
nx rin hi- -·- ·-·
DY rig h : -
-
4
3
2
1
0
-1
~···!1' ~
-2 \ 1\
I
-3
......
r
!
-5
:--...._
;_......-
"""-><:
,...,.....-:.-----
............ ~
I
T'
\
;_......- ~
;_......:-._
~
!
-4
\I ~ I
\I ~ \ --.:--.... :-._
i
I
I
.....
...
~.
\
"/
......
:-·-·
-·-
;....
:-._
,__
:-·- ><"
--
.
~
~
;....-
\
~
_.,..
~
------\
;....--
'"~'I
::ms
(
/
2
3
1.
4
5
6
7
8
\
..
f\ i
V.
\
\=
v1
:~
\
...
i5A
HOU RS >
i
1
~\
~
-~ ...
tf\
'IME OF
-lOO
...
\.
I
__....__....~
~;....-
-9
.. -· :-·-
.. -·
\ I ~\
I \
I
\IV l -
-8
"""- :--....
.~:·
~
-7
~
~ ......
/
\;
j
-6
.-
\
~
~
I
I
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
MAXIMUM DIFFERENCES
left:
left:
dx right:
dx right:
dx
dx
1)
2)
3)
1
2
8. 0
4.0
4. 0
4.0
4. 0
4.0
3.0
3. 0
MAXIMUM DIFFERENCES
MEAN DIFFERENCES
2
3
6.4
1.1
2.5
1.1
-1.9
1.4
.1
-2.9
•8
1.9
•8
3.1
4. 0
4.0
3. 0
4. 0
1
dx
dx
dx
dx
left:
left:
right:
right:
3.0
3.0
3.0
2.0
2
2. 0
2.0
1.0
2.0
MEAN DIFFERENCES
2
3
1
. 9
1.4
1.5
.4
1.1
.5
•8
. 5
-.6
3. 0
3.0
3.0
2.0
.8
.7
.7
1) after time 0
2) between 2 successive measurements
3) after 1/2 hour
after time 0
between 2 successive measurements
after 1/2 hour
COORDINATE DIFFE:RENCES (UM)
COORDINATE DIFFERENCES {UM)
lO,-·-·:D~X.:···l:·e--f~-~t·:························:·················:··························:····················:····················::
10
DX left
DY left
!'lY
~; nh~
1
--
•
•
•
DY right
3
I
\/
~I
l II
::w 1\
·-\ I ___y
2:-
v
~
J
-1
-2
············-·····:······
n ....•.
·n··········
.•
_·:: --
DY righ
--
•
/"
(\
/
I
~!
•
/
\ I
\I
~I
/
/
"""'/
""/~\\'..
//'···,., )'
\
-3
/
'·.
··,.,_
~
v
,/.//
/
\
\
\/1'
v
3
4
•
5
5
6
6
7
7
8
8
9
9
OF OBSERVATIONS (
HOUR~
TIME OF OBSERV'ATI.ONS .( HOURS )
)
-1 0 0
-1 0 0
Figure 2.
Example of results when the photo carriers had been
moving between measuring times. BC-2, measuring
anticlockwise.
;
l
Figure 3.
2
3
4
Example of results when the photo carriers had not
been moving between measuring times. BC-2.
MAXIMUM DIFFERENCES
1
8.4
3.6
left:
dx left:
dx right:
dx right:
dx
1)
MEAN DIFFERENCES
2
3
6. 7
1.6
.2
-1.3
1.3
-1.8
-1.1
.8
.6
-. 3
1.2
3.8
2
4. 3
3.5
3.3
2.2
5.1
3. 0
1.5
3.1
2. 3
5.1
after time 0
4.3
3. 0
3.3
5.2
MEAN DIFFERENCES
1
2
3
5.4
1.2
2.9
-1.7
1.3
1.2
.5
1 .1
-1.3
-.1
1.2
3.0
after time 0
2) between 2 successive measurements
3) after l/2 hour
COORDINATE DIFFERENCES (UM)
10~------------------------... ---·-----------------------------------,----------------··---------·------ --------------·-----·-·······----------------------------·-------·------·--- ...
DX left
DY
left
fll(
ri
DY
right
.~
DY
left
--
mr ,.;""+DY
/
•
/
\I
s--------7
4
lO·,·------·D·X···l··.,··f--t··---~-,_----·······----·-------------,--------------------,--------------------,-------------------------------,---- ... --.................. --- ...... .
-·-·-
-
/
/
j
3
1)
dx
2) between 2 successive measurements
3) after l/2 hour
COORDINATE DIFFERENCES (UM)
......
......
dx
dx
dx
MAXIMUM DIFFERENCES
1
2
left:
7.3
2.8
left:
3.0
3.4
right:
3. 3
2.4
right:
5.2
4.6
7"-V
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ,_ _ _ _ _ _ _ _ _ _ _ ,_ _ _ _ -;- - - - - - - - - - - - - - - - '- - - - - - - - - - - - - -·- ·"- - - ·- ·- - - - - - - - - - -·'- -·- - - - - - - - - - - - - - '
2--------~
/.....,.-·-·-··
)"· ~
"
3
/~
'j
1
1/
/
/
n __
~
·~------_v--""Y.~
:-l~=~··,----.-:::::·
. . ._1
. .~· ._. ·-·-·/ -~- - -. . .-.;-. - - ·-/ - - - - ·-'·- _~._-_._-__·__-._ _-_,_ _· _~ - - L! ~
------_;_,/
v
............................
"'
··................
.............
_____j ____ _______ ..........L.....___·-__._ -__·__•_____________ __
4~----s;~-------
.......... ; ....
--
.......... :•
--·--------'--------------------
-6~-------------·---·-·c•----·------------
------
.;.....................; ......................... ; .................;....................... ,
- --- ----- -------;------------· ------- .. ,............................. , ......................, ........................ .
···-·'•---
-----------"-----···---------'·--····----·----------·--·•···
-7'~-----·---·----------------i·--·-------··-----·--·--·-····-----------
-
--·-----·----+·---------------<
-~--------------------··----···-------------·------i----------····--·--------·----i----------··----------------'
-8~----------·----------··--"·--·--·---········----·--···---------------------'---------------·--·-----··--·---------··--·----------------'·---------------------------------'-------------------------------~
.................. ; ..................... ; ................. ;..
5;~-----·--------·---------''--------------------·-··'-·····--·--------------~--------------------'
------
-----·-----•-- ·----
.. ;
'---·----------------------•-------------------------'
6~-----------------------------··<·----·--·---·-----------·-··-- ----------------; ............................... ,................ , ......................; ......................... ,
-1'~-----------------------------'-------------····-----------•----------------·--······
........................: ............................ :...............................; ........................... .
-8~--------------------------·----'··---------------------------·•------------·---------------~-----------------·--·····----'--·-------------·------·-------i ............................: ....................... ;
-9~-------------- ...............,................................. ;...................... ; .........................;....................... ;............................... ;.............................. .
•
TIME
OF OBSERV'.ATl:ONS ( : HOURS )
TIME OF Ol'!SERV'A!"l.CJNS (. HOURS )
1~--------~------~~------~------~~------~--------~------~
Figure 4.
4~---------·-------------------·----------- ............... ;
Example of results when the
moving clockwise. Planicomp
carriers had been
1~--------~------~2------~;~------~;------~--------~----~
Figure 5.
Example of results when the photo carriers had been
moving anticlockwise. Planicomp Cl30.
In the following figure~ the changes in the coordinates of four
points in the plate are presented in the xy-plane. The big black
spot shows the location of the first measurement of the day and
the smaller black dot of the last.
~Y
Left stage
i
i
II
li
i!
i
!'
l
!
i
!
i
.
!
!
,.
i
ll
i
I
i
l
I
i
l
i
l
=t=r==r]::=r[~t=x=ll::=~--:l~:r=-r=-~:r:.~~r:~tl~cr=r::
I
I
i
i
I
I
i
'
I
'
I
!
1
I
l
!
I
'
I
i
!
I
1
i
i
i
i
!
i
I
!
'
:
I
:
'
•
•••~•,..••loooooo-UO!U-OoOOo•l••••oUhoo.f.•n-oo•-f••-uooooJooouooooooiooooooOoooo~ooonooo•oo•~.-••••o-oo!.,_.ooo-oooloouooo•ohJOU••oo•oooioHHoooooo!ooouoo•ooo~ooonoHoOoloouuooooJoooOoo-•••!o•ooooooOoo!•o-ooooo••ioo.oooo•ooo
.
.
I
I
I
I
Right stage
. . ~--}. . . .l. . . ~. . . . !.-.! . . . t. . . . .l . . . . .l. . . . ~. . . .~. . . . }. . . .,. . . . !------l
. . . . .l. --.t----+----l----.1
l
I
I
~----I .
1
1
. . . . . .1. . . . . .t. . . . . r. . . . .~'"___. t. . . . . l. . . . . I. . . . . l . . . . . !. . . . . .t. . . . . .t. . . . . 1. . . . . t"-..-r·----i. . . . . .t. ·-···r·--.. ,. . ---~,----,-!---- 1----..
i
!
!
i
i
I
!
I
I
I
..........t........... ~ ..........~...........+........... ~ ..........~ ...........t...........~..........~...........~. -.....+..........~. . . . . . f...........!. . . . . .~ . . . . . .~--. --.J..__..,t . . . . . .t ..·---·+·"'""''
!
!
I
!
i
l
i
i
j
i
I
l
I
I
I
I
1
l
l
l
!
1
1
l
~
i
!
I
I
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I
!
1\)
Q)
(()
L--5-.~---~--~--~--~~--~--~--~~----------~--------------------~~--~~
I'""
Figure 6.
I
i
!
Example how the coordinates changed on the left and
on the right stage during one test day. DSR-11,
measuring clockwise, photo carriers moving between
measuring times.
I
I
i
I
!
1
l