Verslagen
materiaal dat andere disciplines kunnen verschaf
fen moet je iets opbouwen dat goed werkt, wat een
goede beschrijving oplevert, of waar een goed
ruimtelijk plan uitkomt. De werkwijze van een in
genieur is niet voorgebakken, hij zal hem zeif moe
ten vormen.
Of je je als geodeet nu richt op de beschrijving van
de wereld of op de verandering, veranderen doe je
altijd iets: door de beschrijving wordt het beeld wat
anderen van de wereld hebben anders en daarmee
hun handelen, door nieuwe werkwijzen te ontwik
kelen grijp je in het leven van je medewerkers in
(automatisering!), en door de grond anders in te
delen bij land- en stadsinrichting geef je een heel
andere richting aan allerlei sociale en economische
processen. Als ingenieur moetje leren deze gevoigen
van je handelen zo goed mogerijk te overzien.
Naschrift
Dit artikel is een bewerking van een college voor eerstejaars
studenten, in het kader van „Inleiding Geodesie". Het was
m'n bedoeling het pas te publiceren nadat ik het had voor
zien van schema's, voorbeelden en toepasselijke literatuur.
Helaas, het tijdschrift had weer eens kopijgebrek
INTERNATIONAL SYMPOSIUM ON
ELECTROMAGNETIC DISTANCE MEASUREMENT
AND THE INFLUENCE OF ATMOSPHERIC
REFRACTION
Wageningen, May 23-28, 1977
At the invitation of the Netherlands Geodetic Commission,
The International Association of Geodesy held a symposium
on the above mentioned subject at Wageningen (The Nether
lands), May 23-28, 1977.
The symposium was organised by the Department of Sur
veying and Photogranimetry of the Agricultural University
at Wageningen in cooperation with the International Agri
culture Centre, who also provided the accommodation.
Some 70 scientists from 18 different countries participated.
The symposium was structured around the following topics:
A. Electromagnetic Distance Measurement:
1. Wave propagation problems in EDM;
2. Instrumentation and Calibration;
3. Optimization, reconnaissance and observational pro
cedures in EDM networks;
4. Ranging to satellites;
B. Refraction:
1. Ionospheric and tropospheric refraction;
2. Multiple wave methods.
These topics were of special interest to members of the Special
Study Groups 1.42 and 1.26 of the IAG.
Twenty seven papers were presented. They will be published
in the Proceedings of the Symposium.
A workshop was conducted, and a special meeting of the
members of the SSG 1.42 took place. Finally some problems
on laser-safety were discussed. Some firms exhibited EDM
and positioning apparatus.
The resolution committee under the chairmanship of dr. K.
Poder issued the following resolutions, with the approval of
the participants.
1. This symposium supports and encourages investigation
into the use of the multiwavelength principle as applied
to the elimination of refractional influences on Geodesy.
It recognises the great need for instruments that are able
to give directly refractionfree angles and distances and
urges that all efforts should be made to develop such
instruments.
2. The symposium recognising that studies of wave propaga
tion in a turbulent medium become increasingly impor
tant, recommends that the scope of these studies should
be such as to include already available research results
from other branches of science.
3. The symposium recognising the need for further investiga
tions of the spectra of geodetic measurements in conjunc
tion with results from boundary layer meteorology,
encourages the search for quantitatively complementary
methods to determine the effects of electromagnetic wave
propagation in Geodesy.
4. The symposium noting with concern the form taken by
preliminary and developing user guidelines for lasers,
feeling that unnecessary restrictions are being imposed
while in some respects not providing adequate safety
recommends that the AIG establishes the appropriate
contacts to ensure the development of a safe and reason
able code of practice.
5. The symposium thanks the Netherlands Geodetic Com
mission, the International Agricultural Centre, Wage
ningen, and particularly the Department of Surveying and
Photogrammetry of the Agricultural University, Wage
ningen, for the excellent arrangements for this meeting.
A date for the next EDM/Refraction symposium has not
been decided upon.
The following papers were presented:
1. E. Tengström: Keynote address.
2. R. H. Bradsell: Longterm stability of an NPL III wave
length standard.
3. R. H. Bradsell: A simple calibrator for the mekometer
EDM instrument.
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