Exploration and exploitation of natural
resources is a very important activity for
the continued economic growth of the
society. Many devices at different stages
of human civilisation were introduced for
the exploration of natural resources. In
the modern age Remote Sensing Technique
is one of the best tools for surveying natural
resources particularly in the inaccessible
areas. Modern remote sensing system from
space is the result of the development
process which began in the U. S. A. in the
mid sixties. This led to the Earth Resources
Technology Satellite ( ERTS) project
of NASA in 1970, now called LANDSAT.