i83
An instrument resembling the one just mentioned is the Auto-
Trol Corporation model 3700.
It should be noted that most electronic drawing tables and co-
ordinatographs also possess the ability to record the co-ordinates
of set points. However, the operations needed for this are often
rather cumbersome.
c. Photo-electric area scanners
As a representative of this type of instrument I mention the
Integromat made by the German firm of PEK-Electronic. The map
on which the area is to be measured is stretched on a drum, which
is available in several diameters between 30 and 80 cm. The drum
rotates at a speed of 2-3 revolutions per second. Photo-electric
scanners moving along the drum in the direction of the axis with
a constant speed deliver 10,000 pulses per revolution to a pulse
counter. The result appears on punched paper tape or on magnetic
tape. Scanning occurs in successive tracks, each 0.2 mm wide;
three tracks are scanned simultaneously. Pulses are only issued
when a black coloured area passes the scanner. Although the area
measurement itself is quick, the preparations seem rather cumber
some. First of all, the map has to be drawn (or reproduced) in red;
secondly, the parts whose area have to be measured should either
be blacked in by using a felt pen or be stripped from a stripping
copy. If, and this is a normal case, the area of all the plots on the
map has to be measured the preparative manipulations grow more
complex. These activities should be weighed against tracing plot
outlines with the magnifying glass of an electro-planimeter, or
against pointing to boundary points by means of a co-ordinate
reader.
From the above it appears that also in the field of automatic
(mostly semi-automatic) area measurement, there are various
possibilities for the surveyor. He only has to decide what type of
instrument in general and what instrument in particular is most
suitable for his needs.
SUMMARY
The report is a continuation of the report issued by the author in behalf of
the Congress of Rome in 1965. It is attempted to give an insight into the
actual state of automation in geodesy.
In 1 the general aspects regarding automation in geodesy are reviewed.
Attention is drawn to the miniaturisation of electronic circuits and the
increased, speed of the peripheral equipment, which are of special importance.
2 reviews the automation of field activities. The author does not consider
mark-sensing or other grid-marking systems satisfactory and emphasizes the
advantages of direct registration systems, simply by operating a push
button. Miniaturisation of electronics, thus reducing size, makes this develop
ment more practical for field use. Code theodolites and pulse counters are
brought up for discussion. Little progress of automatic pointing is mentioned.
A few new instruments are noted.
3 the author first indicates the inefficiency of the increasing number
of Service Centres for computer activities. A sketch is provided for an in-
