On the Statistics of Sea Clutter
Abstract
A model for the statistics of sea clutter has been developed from scattering theory and the composite surface-scattering model. The model postulates that sea clutter is exponentially (Rayleigh envelope) distributed for glassy seas and should tend toward the lognormal distribution (in particular for horizontal polarization) with increasing roughness. The lognormality of sea clutter arises from the tilting of the slightly rough patches by the large-scale roughness (undulating surface). An empirical identification of the statistics of sea clutter taken with the Four-Frequency Radar system shows that in general the distribution of sea clutter is intermediate between the exponential (Rayleigh envelope) and the lognormal distribution. However, for calm seas and small sample sizes (less than about 200 independent samples) the distribution of sea clutter may be approximated by either the exponential or the lognormal distribution. The first five central moments of sea clutter (in decibels) have been calculated for moderate and rough sea conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 1971
- Accession Number
- AD0737200
Entities
People
- G. R. Valenzuela
- M. B. Laing
Organizations
- United States Naval Research Laboratory