In the early 1980s, a young Ph.D. student prepared a dissertation on the use of computer algorithms to process raster data in land conservation applications. His groundbreaking research became known as Map Algebra, a vocabulary and conceptual framework for classifying ways to combine map data to produce new maps. While primarily applied to raster data sets (GRID and image data), the same concepts can be applied to many types of cartographic information, and Map Algebra has since been extended to 3D, time and other domains. Map Algebra is used for a broad array of GIS applications including: suitability modeling, surface analysis, density analysis, statistics, hydrology, landscape ecology, real estate, and geographic prioritization. While there are different flavors of Map Algebra, the overall concept is still used today in every GIS application that supports raster calculations.
For his immense contributions to the field of GIS through the development and implementation of Map Algebra, Dr. C. Dana Tomlin has been nominated for induction in the URISA GIS Hall of Fame.
Dr. Tomlin has held various teaching and lecturing positions with Harvard University, Ohio State University, Yale University and the University of Pennsylvania since 1975. His coursework in Landscape Architecture during that timeframe has extensively included GIS and cartographic modeling applications. Dr. Tomlin has also provided private GIS consultation services to public and private organizations since 1975 (http://www.cml.upenn.edu/cv/danaCV.pdf).
In addition to his roles as teacher and lecturer, Dr. Tomlin has been involved in a number of high-level ecological research projects during the same time period. He has served as Principal Investigator or in other leadership capacities on projects for the National Science Foundation, Pew Charitable Trusts, the William Penn Foundation, NASA, IBM, AT&T, and Apple Computers, as well as many others. GIS has figured prominently in all of these projects. Dr. Tomlin has also been widely published in GIS journals and conference proceedings in the United States and abroad.
Dr. Tomlin’s singular contributions to GIS extend across a number of years and a wide variety of applications. As a student at Harvard University in the mid-1970s, Dr. Tomlin developed the Tomlin Subsystem of IMGRID as a master’s thesis. A number of analytical functions in IMGRID were later integrated into Imagine, the world’s leading satellite image processing application developed by ERDAS.
As a doctoral student at Yale University in the late 1970s, and as a junior faculty member at Harvard in the early 80s, Dr. Tomlin developed MAP (the Map Analysis Package), which would come to be recognized as one of the most widely used programs of its kind, with several thousand installations worldwide. Before the term “open source” became widely used, Tomlin donated his source code, documentation and other materials to anyone who asked. While probably not the best financial decision, his generosity and collegiality led to the incorporation of Map Algebra vocabulary, concepts and MAP algorithms being embedded in virtually every raster geographic information systems on the market. His work on this original MAP software has been directly inherited by a long list of subsequent software packages including, OSUMAP, MAP II, MapFactory, MFWorks, MacGIS, IDRISI, MapBox, pMap, MGE, IMGRID and GRASS. A couple of these are described in more detail below.
Throughout the late 1980s, the U.S. Army Corps of Engineers and other federal agencies widely used the open source GRASS application, which derives many of its raster analytical capabilities directly from MAP. Dr. Tomlin served as Principal Investigator for the review portion of this project.
Dr. Tomlin’s landmark book, Geographic Information Systems and Cartographic Modeling, was published in 1990 to expand on his earlier dissertation work. In 1995, AutoDesk acquired a South African company whose raster-analysis product was promoted as the truest implementation of the concepts presented in Tomlin’s book. The result is AutoCAD Map, a geographic information system that couples these capabilities with AutoCAD, the world’s most widely used computer-assisted design (CAD) program.
ESRI’s Spatial Analyst application, as well as its predecessor, the GRID module of ArcInfo, was heavily influenced by Dr. Tomlin’s Map Algebra. ArcGIS is generally recognized as the world’s most widely used GIS software product. Dr. Tomlin has provided private consulting services to ESRI since 1990’s related to the ongoing development of these applications.
Since 1978, Dr. Tomlin’s knowledge and reputation have made him a highly sought-after speaker at colleges, universities, and cartographic organizations across the United States and Canada. He has also been invited to speak at universities as far afield as Madrid, Spain and Sydney Australia. Dr. Tomlin has provided consulting services for a broad array of distinguished organizations such as ERDAS, ESRI, USGS, and the National Ministry of Urban Planning and Ecology in Mexico City, to name just a few. Since 1989, he has also provided editorial and proposal review services to a number of cartographic and environmental journals, including those issued by the Association of American Geographers, American Congress on Surveying and Mapping, Sustainable Forestry, United Nations Environmental Programme, and the United States Department of Agriculture.
With funding provided by a corporate donor in 1990, Dr. Tomlin led an informal group of City and Regional Planning doctoral students at the University of Pennsylvania in founding the Cartographic Modeling Laboratory. The Cartographic Modeling Lab conducts academic research and urban and social policy analysis using GIS and spatial research applications. Dr. Tomlin has been co-director of the lab since 1995.
While Dr. Tomlin’s contributions to the field and the advancement of geographic information science have been substantial, his greatest impact has likely been through the students he has taught and mentored over several decades. He is a masterful teacher and has received teaching awards from both colleagues and students over his career, including the Lindback Award for Distinguished Teaching (2002) and the Perkins Award for Excellence in Teaching (1997).
Dr. Tomlin’s decision to advance the technology and benefit others without thought to personal remuneration speaks more eloquently of the man’s character than any testimonial ever could. He has continued to freely share his ideas and insight with students, educators, software developers and others in the GIS industry throughout the course of his career.
For his many distinguished and ongoing contributions to the field of GIS, Dr. Tomlin is truly deserving of a place in the URISA GIS Hall of Fame.