This book is concerned with remote sensing based on the technology of
imaging radar. It assumes no prior knowledge of radar on the part of the
reader, commencing with a treatment of the essential concepts of
microwave imaging and progressing through to the development of
multipolarisation and interferometric radar, modes which underpin
contemporary applications of the technology. The use of radar for
imaging the earth's surface and its resources is not recent.
Aircraft-based microwave systems were operating in the 1960s, ahead of
optical systems that image in the visible and infrared regions of the
spectrum. Optical remote sensing was given a strong impetus with the
launch of the first of the Landsat series of satellites in the mid
1970s. Although the Seasat satellite launched in the same era (1978)
carried an imaging radar, it operated only for about 12 months and there
were not nearly so many microwave systems as optical platforms in
service during the 1980s. As a result, the remote sensing community
globally tended to develop strongly around optical imaging until Shuttle
missions in the early to mid 1980s and free-flying imaging radar
satellites in the early to mid 1990s became available, along with
several sophisticated aircraft platforms. Since then, and particularly
with the unique capabilities and flexibility of imaging radar, there has
been an enormous surge of interest in microwave imaging technology.
Unlike optical imaging, understanding the theoretical underpinnings of
imaging radar can be challenging, particularly when new to the field.
