6

BASICS OF RADAR IMAGING

In this chapter, Section 6.1 surveys several popular imaging radars and possible applications. Section 6.2 covers the geometry of stripmap SAR, which consists of broadside SAR and squint SAR. Section 6.3 describes the relationship between Doppler frequency and radar image processing, where both broadside SAR and squint SAR are covered. A key problem of radar image processing is range migration, which is described in Section 6.4. Radar image distortion and resolution are covered in Sections 6.5 and 6.6. Most hand drawings in this chapter are for illustration purposes and are not to scale.

6.1 BACKGROUND

Imaging radar has been used to measure the motion of the earth's surface to help us better understand earthquakes and volcanoes. It can be used to study the movements and changing size of glaciers and ice floes to understand long-term climate variability. The development of highly detailed and accurate elevation maps is based on imaging radar. Imaging radar is also used to find oil or other natural resources, to study land cover and land use change, to assess the health of crops and forests, and to plan for urban development.

In early 1950, scientist Carl Wiley found that the use of Doppler frequency analysis could improve radar image resolution of side-looking radar. This new finding led to the development of the SAR (synthetic aperture radar) technique. The SAR technique derives from the along-track (or azimuth) processing of the signal data by synthesizing ...

Get Digital Signal Processing Techniques and Applications in Radar Image Processing now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.