John P. Snyder 1997

JOHN P. SNYDER, FORMER WASHINGTON MAP SOCIETY SECRETARY

John P Snyder, Secretary of the Washington Map Society from 1988 to 1992, died April 28, 1997 at the age of 71. He made cartographic history by developing a set of mathematical equations to convert images of the Earth taken from space into accurate maps. Mr. Snyder 's series of 82 equations solved a problem that had vexed experts. Because of the double motion of orbiting spacecraft and the rotation of the earth, images transmitted by Landsat satellites were subject to distortion. A mathematical formula by which cartographers could account for the distortion and transfer a particular point on a satellite image to its accurate longitude and latitude on a map had long been sought. Mr. Snyder came up with the equations using a programmable pocket calculator.

John Snyder was a chemical engineer who transformed a teenage mapping avocation into a full-time career with the U.S. Geological Survey. For this work on the mathematical equations, he received the USGS John Wesley Powell Award in 1978, leading to full time employment with the agency from 1980-1988. President of the American Cartographic Association for 1990-1991, he was also from 1986 to 1991 a lecturer in map projections at George Mason University.. After his pioneer work on the elusive satellite mapping equations, Mr. Snyder became a respected expert, specializing in map projections. He was the author of seven books on map projections, including "Flattening the Earth: Two Thousand Years of Map Projections," published in 1993 by the University of Chicago Press. (Sources: The New York Times; The Washington Post)

This remembrance appeared in issue 38 (Spring 1997) of The Portolan).