Modern airborne and spaceborne imaging radars, known as synthetic
aperture radars (SARs), are capable of producing high-quality pictures
of the earth's surface while avoiding some of the shortcomings of
certain other forms of remote imaging systems. Primarily, radar
overcomes the nighttime limitations of optical cameras, and the cloud-
cover limitations of both optical and infrared imagers. In addition,
because imaging radars use a form of coherent illumination, they can
be used in certain special modes such as interferometry, to produce
some unique derivative image products that incoherent systems cannot.
One such product is a highly accurate digital terrain elevation map
(DTEM). The most recent (ca. 1980) version of imaging radar, known as
spotlight-mode SAR, can produce imagery with spatial resolution that
begins to approach that of remote optical imagers. For all of these
reasons, synthetic aperture radar imaging is rapidly becoming a key
technology in the world of modern remote sensing.
Much of the basic `workings' of synthetic aperture radars is rooted in
the concepts of signal processing. Starting with that premise, this
book explores in depth the fundamental principles upon which the
spotlight mode of SAR imaging is constructed, using almost exclusively
the language, concepts, and major building blocks of signal
processing.
Spotlight-Mode Synthetic Aperture Radar: A Signal Processing Approach
is intended for a variety of audiences. Engineers and scientists working
in the field of remote sensing but who do not have experience with SAR
imaging will find an easy entrance into what can seem at times a very
complicated subject. Experienced radar engineers will find that the book
describes several modern areas of SAR processing that they might not
have explored previously, e.g. interferometric SAR for change detection
and terrain elevation mapping, or modern non-parametric approaches to
SAR autofocus. Senior undergraduates (primarily in electrical
engineering) who have had courses in digital signal and image
processing, but who have had no exposure to SAR could find the book
useful in a one-semester course as a reference.