Dual polarized RCS grazing angle characteristics of internal gravity waves

• Published in: IGARSS '98. Sensing and Managing the Environment. 1998 IEEE International Geoscience and Remote Sensing. Symposium Proceedings. (Cat. No.98CH36174) Vol. 4; pp. 2213 - 2215 vol.4
• Main Author: Trizna, D.B.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1998
• Subjects: Acoustic scattering; Gravity; Light scattering; Optical polarization; Predictive models; Radar antennas; Radar cross section; Radar imaging; Radar measurements; Radar scattering
• DOI: 10.1109/IGARSS.1998.703790
• ISBN: 9780780344037; 0780344030

Grazing angle dependencies of radar cross section (RCS) are shown to differ for horizontally (HH) and vertically (VV) polarized X-band marine radar sea scatter from internal gravity wave (IGW) spatial modulations. For these internal gravity waves, observed off the coast of North Carolina, an IGW crest-to-trough modulation of 30-dB is observed at HH at 1/spl deg/, but only 10 dB at VV. The HH RCS decreases with increasing grazing angle, roughly to the minus one power, whereas VV RCS increases as for the composite model, but only to the first power. The HH/VV RCS ratio is 10 dB at 1/spl deg/, again opposite that expected from the two scale model, and decreases to -10 dB at 10/spl deg/ grazing. The two scale model with wave-current modulation of short waves by wave-current interaction predicts a decrease in modulation as grazing is approached, opposite the results presented. The authors suggest an influence of wave breaking radar scatter sources to explain these internal wave results, similar to arguments made for breaking wave scatter occurring near fronts.