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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