In this chapter, sea clutter is described in terms of its observed characteristics. These observations will provide the foundations upon which the themes of subsequent chapters are developed. Radars operating in a maritime environment inevitably encounter backscattered radar signals from the sea surface, usually referred to as sea clutter. For some applications, such as remote sensing systems, the reception of this backscattered signal may be the main purpose of the radar. Space-borne synthetic aperture radars, with spatial resolutions of a few metres, are used for oceanographic studies, gathering data on waves and currents, sea ice and so on. Scatterometers measure average backscatter over hundreds of square kilometres to measure wind speed and direction over the sea surface.

Chapter Contents:

• 2.1 Overview
• 2.2 The sea surface
• 2.3 Sea clutter reflectivity
• 2.4 Amplitude statistics
• 2.4.1 The compound nature of sea clutter amplitude statistics
• 2.5 Frequency agility and sea clutter
• 2.6 Observations of amplitude distributions
• 2.7 Polarisation characteristics
• 2.8 Clutter spikes and modulations
• 2.9 Coherent properties of radar sea clutter
• 2.10 Spatial characteristics
• 2.10.1 Range Autocorrelation Function (ACF)
• 2.10.2 Power spectrum analysis of range-time intensity plots
• 2.11 Bistatic clutter
• 2.11.1 Bistatic scattering geometry
• 2.11.2 Bistatic reflectivity NBRCS
• 2.11.3 Bistatic amplitude statistics
• 2.11.4 Bistatic Doppler spectra
• References

Inspec keywords: airborne radar; synthetic aperture radar; marine radar; radar clutter

Other keywords: wind speed; Scatterometers; backscattered radar signals; sea surface; radar sea clutter; space-borne synthetic aperture radars; spatial resolutions; oceanographic studies; remote sensing systems

Subjects: Radar equipment, systems and applications