16TH CONGRESS OF INTERNATIONAL SOCIETY OF PHOTOGRAMMETRY
AND REMOTE SENSING
GALILEO DIGICART 40:
AN ANALYTICAL INSTRUMENT BASED ON A PERSONAL COMPUTER
by:
Capanni
rlo,
GALILEO SISCAM S.P.A.
Franco
N
ITALY
COMMISSION II
ABSTRACT
A software has been
that allows us to cont
instrument DIGICART 40
th a personal computer.
The software was written in C
and FORTRAN 77 under
the XENIX
ng
in order to have a
of
compatibili
the
of
approach are presented.
The system allows an
for the real
of
an inexpensive "'supe
!.N.I.R.O.P..VG..I.lO.N. . . .
DIGICART 40
a p
f
and easy to use fu l
analytical
photogrammet
instrument.
Its
hardware
and
software
tions make
to the user all those
ope
ng facili
that
essential for any
stereorestitution job.
Operations for model set-up are drastically simplified in the
DIGICART 40, at the same time a set of
lities for automatic
numerical or graphic mapping are implemented in order to
increase the system
and productivi
The use of a personal computer for the management of the
instrument, the
of XENIX ope
ng
and the C
language
to the instrument a great flexibility and
guarantees us ha
re and software compatibility
th future
informatic products.
Other main features that had been
in account during the
design of the DIGICART are the following:
. Planimetric explo
of the stereomodel
freehand
guiding
with the possibili
of selection of different
speeds and fast
ng on the indicated point .
for altimet
. Handwheel and/or
. Footswitch for
reco
. Modular and inte
to gu
operator in the
use of the instrument.
. High rel
li
of harware and
tware.
All this make the DIGICART 40 an ext
requirements of
rammetr
answer to the
. The ste
the photograms
The computer
parameters and
updating the
The
control
inte
and d
Software for
Peripherical
flat bed
parts can be
r
allows the
and the
that
real
observation of
measurements.
orientation
model coo
nates for
manages
the
data
part and the computer
r on-line and
rs and g
In fig. 1
a
the parts above
line plotting like
screens ..
the connection of
shown in fig. 2.
TROI'IIC
CON TI?OL Vf-117
PARALLEL I/O
TERFACE
PERSONAL
VIEWER
C0/'1PU
RS 2 2
IC
DEVICE
.
1
ram of the DIGICART 40
1
F
m
2 - The DIGICART 40 system
II
THE STEREOVIEWER
optical
unit
basical
a high precision
stereocomparator.
res are mounted in a main carriage
movable on
gu
that materialize the
reference
for instrument coo
The right optical channel can be moved along the above
mentioned axis, allowing the horizontal and vertical parallaxes
elimination.
Main carriage and optical carriage are moved by four computer
controlled servomotors.
During model
movements can be manually controlled using
a special free(pantograph) and thumbwheels;
software
are
After inte
and absolute orientation, motors are
cant
led
computer.
It reads model coordinates,
transforms
in
coo
nates using
linearity
equations and sends the up-dating positions to servomotors
th
elect
control u t.
THE OPTICAL SYSTEM
The
fig.
3 shows the collimation optics . Observed field is
by a first lens that form an image on the focusing
plane of the measu ng
by a second lens
ng a part of the
to transport the
image on
Changing eye-pieces we can have
~
I
a
3
ram of the
ax and 12x ..
THE CONTROL ELECTRONIC UN
Main
data
plus control of the four
car
The interface
the latest up-to-date
digital
roprocessors
and
a
modular
structure in
and easy
ntenance.
We can
parts in the elect
inte
. The
CPU, the EPROM
the
of pa
ports
for
roprocessor
. Four cant
are
containing the counters of transducers
r
and the servomotor d
rs ..
. The power
p
ng the val . . a,~q;;;;.:;:::)
transducers and servomotors .
. The parallel
interface
board,
be
on the bus
the personal computer in
ng data from
The following block
of control interface.
g. 4
ram (f
. 4)
u
ts
MODERN PERSONAL COMPUTER: THEIR CHARACTERISTICS
ng a computer
ste
When
r one
must have well present in
facts:
a)
real
fu
necessary in a ste
r control
require a very
compu
power
b)
the operator's
must be as easy as
In other words one must never fo
the operator f
iness
of the machine .
have made
A very
roprocessors
wo
ng
in a short pe
of
the personal
ts and 20 MHz clock. At the
to carry out
ng
in several
a fundamental role in
computers also for hobby
a personal computer
purpose, so
ng more and more numerous.
1 a "personal computer··
a machine
th
coprocessor, 640 Kb of
t processor, floating
g
options
20 or 40 Mbytes hard
personal in a
tors) that t
at a very
p
ng a personal as a ste
r control
valued and found
appeared
of pe
one
are not
one to
to a class
a simple process.
Modula
as al
a personal computer can be
allowing display and
transformed into a graphic work
g
processing of data.
to operate ..
THE OPERATING SYSTEM
Talking about personal computers
ng
in
up to now
r its power
the
between the
When the PC AT computers,
appeared on
market, a new ope
appeared.
XENIX can be regarded as
hardware characte
the same commands format
r.
ng to choose the ope
it was
r that some
remembe
ng the MS-DOS
more frequently
; it put itself in
UNIX ..
I80286
rap rocesso r ,
XENIX
to
fit
it
ng and
for our DIGICART software
be put from the MS-DOS,
the
the
1
memory access and the
li
of a
of the modern
, we can
in account
MS-DOS was
rn for
roprocessors so, it uses the more powerful 80286/386
ng all
, we decided on
ng
XENIX operating
for software development.
choice had been val
and
advantages we found are detailed below:
ng
tools
are
very
efficient
and
powerful;
ng and mul
reen mode offer to the programmer a
ronment for software
no 1
ts
of memory and
created under
any problem. In
operating
ng the
systems
computer ..
The
th UN IX allows us to look at
future
of the
wo
or
Ste
ng instrument.
The last thing we want to say is that the XENIX software
more
, but it is limited at the drivers
for external devices and in any case at the sta
ng
of
the programming work. User interface can be very simple and
friendliness can be reach by a good user.
SOFTWARE ORGANIZATION
rs can be
the DIGICART 40
Two fu
software; it
software structure.
first one
the picture-carriages
the
rithm to
after the
ng
input coordinates from the
phisical devices.
second
layer
the software
that performs model
interp
of commands, printout of results
tware:
used to
the opportu
to use ce
n
in the p
instruments, the C
ronment ..
of XENIX
nary phases
benchmark carried out during the prel
gave the fol
ng resu
C
faster than
ng; FORTRAN is
and drivers bui
faster in
nt calcu
ferent languages are
in order to
Subrou
the
ng
management ..
MAPPING OPERATIONS
Several
software
are one of the most
of DIGICART 40. The following
n
can be
red:
.. Stereomadel
.. G
and
.. Close-range
.. Aerotr
tware are summa
Pri .................. ""....
rtant
rammet
in
the
pa
te a
supported
g
screen;
rmats
used
in
data
selected
the user. Data can be collected
rent modali
nt
nt or stream
intervals
the prafi
allows the
i
ng
gr
and
very
the
nts) by a
project
obse
and
DIGICART 40
to the user a powe
A g
support
purposes:
.. To
in the work of
.. To make
lable a powe
inte
an line
occur ng at
Data stored on the disk can be subdiv
elements: si
nts, open and closed
During data collection
information is recorded
cal
tu
file",
file
ns
r
PHOTOGRAMMETRIC DATA BASE AND GRAPHIC FUNCTIONS
in a file
cades and
coo
rep
to
some
creates an
au
extra info
called
fi
ns i
about
code
to an element, number of
nts for each element,
to the coo
nate file, color
selected when the
displayed on the screen.
files, built at the
nning of the work,
general instructions to the system like
normal
used, defi
of
, color-pen
to
as
in
are
We would like
the g
are available:
rep
screen or
r
. Numerical and g
ng
. Tests for consistency of data and codes
ng from surveying or map
. Data
integration with
digi
ing.
Graphic functions
li
to zoom, to work
to output
levels (display
elements)
numerical map on the plotter.
The g
ting
for first cor
it includes
tu
errors;
or t
like total or pa
squa ng. All the
li
line ..
to
are
n
out.
li ty we want to
k about
data base
integration
th data coming from map digi
ing, survey
instruments and of course using the computer keyboard.
I
ned from digitizing
supported by a
time
alga thm
that
allows
the
real
ground
of
tizing
coordinates
in
nts can be pro1cessea
like
elements of data base.
on a pe
few
years
features.
the instrument
not last of the
work
computer
in the world
ty of al
a
means
inte
computer, an
ago,
offers
to have a
the computer.
Talking about
ng it could be very inte
nt out an
, at the moment under
in
our 1
ratory, that will make
lable a very
and
functional superimposition device.
Cards, fully
th pe
computer data bus, can
for displaying on high resolution
photography and,
superimposed, the photogrammetr
us scaling
This
.................. ., ng, could be
ng" of
used also for
ng and
ntenance.