Coherent Multilook Radar Detection for Targets in KK-Distributed Clutter

This Chapter examines the problem of coherent multilook radar detection of targets in the sea from an airborne maritime surveillance platform. The radar of interest operates at high resolution, and at a high grazing angle, with frequency in X-Band, and is fully polarised. Typically, such surveillance radars are searching for small targets, such as fishing boats or submarine periscopes. When a radar transmits signals toward a potential target, the returned signal is distorted by a number of sources. The signal will be affected by thermal noise in the radar. Atmospheric conditions will also distort the signal. In a maritime surveillance context, backscatter from the rough sea surface will result in what is known as clutter returns Levanon (1988). In most cases, the first two sources of interference can be modelled by Gaussian processes Gini et al (1998). However, the sea clutter distribution is much more complex to model. Much research has consequently been dedicated to modelling sea clutter returns. Once a suitable clutter model has been proposed and validated, detection schemes can be designed using statistical methodology. This Chapter will construct radar detection schemes for a modern clutter model used for the scenario of interest. Before introducing this, a synopsis of clutter models is provided. Useful references on radar include Levanon (1988); Mahafza (1998); Peebles (1998); Stimson (1998). For statistical hypothesis testing, consult Beaumont (1980). For a detailed description of statistical and probability methods employed here, consult Durrett (1996). A useful reference on statistical distributions is Evans et al (2000).