High-Resolution Radar Sea Scatter, Experimental Observations and Discriminants
Abstract
An experimental study was made of the characteristics of high- resolution, low-incidence-angle, radar sea scatter. The experiment utilized measurement made with several radar systems with varying pulsewidth, frequency, and polarization while the radar-illuminated sea surface was observed optically. Measurements were performed at both shallow-water and deep-water sites, and they revealed that all high-resolution, X-band radar, sea return is heavily amplitude modulated pulse-to-pulse, with modulation frequencies significantly higher than those expected from rigid targets. Moreover, under many conditions of wind and sea the backscatter in individual range-resolution cells was found to be characterized by significant periods of extremely low level return interspaced between relatively high level spikes. High-level returns were often associated with turbulent breaking water, as indicated by whitecaps. Some marked distinguishing features were also noted in the spatial and time-varying characteristics of the high-resolution sea scatter as a function of radar polarization. For upwind conditions and vertical polarization, it was observed that backscatter was consistently evident from many portions of the nonshadowed sea surface, while horizontal polarization produced sporadic returns, often with a 'burstlike' character. The distribution and level of the data taken with vertical polarization generally agreed with those taken at lower resolution by other researchers, while the data taken with horizontal polarization tended to be more nonexponential in character.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 05, 1982
- Accession Number
- ADA113394
Entities
People
- James P. Hansen
- Vincent F. Cavaleri
Organizations
- United States Naval Research Laboratory