David C. Mason received the B.Sc. and Ph.D. degrees in physics from the University of London in 1963 and 1968, respectively.He has worked as a Staff Scientist for the U.K. Medical Research Council automating human chromosome kayotyping (1969-1978), and then on military image processing for Plessey Electronic Systems Research (1978-1983). Since 1984 he has been Deputy Director of the NERC Unit for Thematic Information Systems, carrying out spatial data handling techniques research for the environmental sciences. His research interests include the automated extraction of information from remotely sensed images, the design of databases for very large images and maps, hierarchical spatial data structures, and higher-dimensional geographic information systems.