The GIS History Project
The TIN Case Study
TINs. The TIN, or Triangulated Irregular Network, represents a topographic
elevation surface by a tesselation of non-overlapping triangles, with elevations
at their corners. TIN has been selected an a high-priority case study in
the history of GIS for a number of reasons. For one, the TIN model was
apparently discovered or invented independently in several different places
and research groups at about the same time; thus it makes a good example
for the study of ideas whose "time has come." The best known TIN project,
which coined the term, was led by Thomas Poiker, and was funded at a Canadian
university (Simon Fraser University, or SFU) by an agency of the US Defense
Department (Office of Naval research, or ONR). One early application of
the TIN within that project was supposed to be matching a radar altimetry
profile against a terrain model on an aircraft--this almost certainly a
slightly disguised version of the cruise missile guidance problem. However,
there apparently was no actual work on profile match, with all of the work
on more general aspects of the representation and algorithms for data input
and display. In any event, at least some aspects of the intended applications
were of direct military interest, in retrospect probably weapons-related,
yet the project was "unclassified" and at a foreign institution. A key
question will be "who knew the true context of the project?" Another interesting
aspect of TIN is that the approach diffused into a major commercial software
package (ARC/INFO) through the hiring of a student who had studied with
one of the researchers from the SFU/ONR TIN project. We will also study
the apparently-independent developments of the TIN model at a consulting
firm in Ohio (W. E. Gates and Associates), in an academic geological context
by Christpher Gold (then at the University of Alberta, Canada), and in
industry in Germany. Sources of 'insiration' for the invention of TIN will
be sought in each case, to see if there was a common 'spark' or whether
this is a true case of independent invention and re-invention. This case
study may also pursue some other academic, non-classified efforts to develop
profile matching algorithms.
David
Mark's GIS/LIS'97 paper on the history of TIN
World Wide Web Resources for people researching the history of TIN:
Last updated on August 29, 1997.
since 28-Aug-97
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