DELINEATING URBAN AREAS FROM LANDSAT IMAGES USING
DIGITAL PROCESSING; A COMPARISON WITH GRID- BASED
PHOTO INTERPRETATION
Ir. C.A. de Bruijn
INTERNATIONAL INSTITUTE FOR AERTAL SURVEY AND EARTH
SCIENCES (ITC), ENSCHEDE, the Netherlands
Department of URBAN SURVEY
1. Introduction
During the past decades, urban areas all over the world have known
considerable physical changes, and planners and decision-makers are
becoming increasingly aware that they have no suitable monitoring
systems available to be timely informed on directions and volumes
of such changes. Not only in developing countries, but also in coun-
tries with a long administrative tradition, it is often extremely
difficult to get reliable up-to-date information on the growth and
extent of the urbanized area. (SMITH et al, 1977).
In most cases, such à situation may improve drastically by intro-
ducing aerial photography systematically as a complementary data
source, (DE BRUIJN et al, 1976), but the low price, the relatively
easy availability, the digital classification possibilities, and
the high temporal resolution of satellite imagery makes some
decision-makers wonder if satellite images could not be used instead.
With the actual spatial resolution, however, it is obvious that
satellite information may play only a minor, often accessory role.