Ocean microwave backscatter from the LOGAN experiment

High resolution, X-band (9.75 GHz) sea-clutter data were collected at grazing angles of 1/spl deg/ and 2/spl deg/ under a variety of sea states as part of the LOGAN experiment. Backscatter from sea spike events in the vicinity of wave crests allowed the dispersive properties of the ocean surface waves to be estimated from measurements of the radar cross section (RCS) as a function of range and time. Modulations of the RCS are shown to be consistent with the presence of two types of sea-spike scattering phenomena. Variations in Doppler shift and RCS in response to the passage of wave crests through single range cells reveals an asymmetry between upwave and downwave sea spikes.<>