Introduction - Hyperspectral Image Fusion - page 1

Chapter 1
Introduction
The earth is full of different resources such as minerals, land, water, and vegetation.
As majority of these vast resources have been proved to be a boon towards the
progress of mankind, the identification of such resources has always been one of the
primary goals. Earlier methods of discovery and identification of resources required a
visit to the actual field followed by the collection of samples needed for the analysis
of resources in the pure or mixed form. However, advances in technology have
revolutionized the ways of collection, analysis, and management of data. Remote
sensing has proved to be one of the highly effective technologies to observe our
planet through a huge collection of data.
Remote sensing may involve acquisition of pictorial information about a partic-
ular scene or region on the earth without any kind of physical contact. Along with
the natural resources, it also provides information about the man-made resources,
e.g., urban land usage. The extensive information gathered is provided in a map-like
format whichmakes remote sensing images a highly useful and a viable source. Addi-
tionally, it also facilitates a repetitive coverage of the same region on the earth, quite
useful for understanding the temporal behavior. This vast information has served a
large number of applications as well as research areas including resource exploration,
geological surveying, mineral detection, environment monitoring, weather analysis,
land cover, and vegetation analysis. Today, remote sensing has become an indispens-
able tool for the earth observation. The success of remote sensing can be attributed
to many reasons. Firstly, it does not require a physical presence of the operator or the
instrument at the site location. The images are captured by the sensors that are several
thousand meters above the site. The satellites can easily collect the data from areas
practically inaccessible to the man. Secondly, remote sensing technology has proved
to be very economical. It covers large areas at a very low per unit cost. Also, the
process of data collection is very fast. Lastly, with recent advancement in the remote
sensing imagery, one is able to obtain more and more accurate and robust data.
One may regard the process of remote sensing as something that reads the data by
means of various sensors. The sensors can obtain these data from different sources,
where the most common sources include acoustic or electromagnetic waves. This