Abstract
Radar signatures of sea surface films of different origin are investigated, which have been acquired by airborne and spaceborne multi-frequency/multi-polarisation microwave sensors during the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR), missions in 1994, as well as by the ERS SAR in 1996–98. During SIR-C/XSAR, controlled surface film experiments were performed in the German Bight by deploying various quasi-biogenic substances and mineral oil on the sea surface, in order to study the radar signatures caused by surface films of different visco-elastic properties. In general, our results show that multi-frequency capabilities, rather than multi-polarisation capabilities, are needed for a radar-based system for the discrimination of marine surface films. We show that, under high wind conditions (> 10 m s−1), a discrimination between the different kinds of surface films is very difficult, whereas at low to moderate wind speeds (≤ 5 m s−1) a discrimination seems to be possible. This finding is supported analytically by means of a new model for the wave number-dependent radar contrast at high wind speeds (> 10 m s−1) and statistically through the analyses of more than 700 ERS SAR images. In addition, results of laboratory experiments are presented that were carried out in the wind-wave tank of the University of Hamburg. At certain wind-speed ranges a different damping of bound and freely propagating surface waves by monomolecular surface films is observed, which may explain the high radar contrasts measured by the microwave sensors.
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7 References
Alpers W and Hühnerfuss H (1988) Radar signatures of oil films floating on the sea and the Marangoni effect. J Geophys Res 93: 3642–3648
Donelan MA and Pierson WJ (1987) Radar scattering and equilibrium ranges in wind-generated waves with application to scatterometry. J Geophys Res 92:4971–5029
Gade M (1996) Untersuchungen zur Abbildung biogener und anthropogener Oberflächenfilme auf dem Meer mit Hilfe von Radarsensoren. Dissertation, Univ. of Hamburg; Shaker, Aachen, 176 pp
Gade M and Redondo JM (1999) Marine pollution in European coastal waters monitored by the ERS-2 SAR: a comprehensive statistical analysis, Proceed Intern Geosci Remote Sens Sympos (IGARSS)’ 99, IEEE, Piscataway, NJ, USA, 1375–1377
Gade M, Alpers W, Hühnerfuss H, Masuko H and Kobayashi T (1998a) The imaging of biogenic and anthropogenic surface films by a multi-frequency multi-polarization synthetic aperture radar measured during the SIR-C/X-SAR missions. J Geophys Res 103: 18851–18866
Gade M, Alpers W, Ermakov SA, Hühnerfuss H and Lange PA (1998b) Wind-wave tank measurements of bound and freely propagating gravity-capillary waves. J Geophys Res 103: 21997–22010
Gade M, Alpers W, Hühnerfuss H, Wismann VR, and Lange PA (1998c) On the reduction of the radar backscatter by oceanic surface films: scatterometer measurements and their theoretical interpretation. Remote Sens Environ 66:52–70
Gade M, Scholz J and v.Viebahn C (2000) On the detectability of marine oil pollution in European marginal waters by means of ERS SAR imagery. Proceed Intern Geosci Remote Sens Sympos (IGARSS)’ 00, IEEE, Piscataway, NJ, USA, 2510–2512
Hasselmann K (1960) Grundgleichungen der Seegangsvoraussage. Schiffstechn 7:191–195
Hühnerfuss H (1986) The molecular structure of the system water/monomolecular surface film and its influence on water wave damping. Habilitationsschrift, Univ. Hamburg, Dept. of Chemistry, Hamburg, Germany, 245 pp
Phillips OM (1985) Spectral and statistical properties of the equilibrium range in wind-generated gravity waves. J Fluid Mech 156: 505–531
Plant WJ (1982) A relationship between wind stress and wave slope. J Geophys Res 87: 1961–1967
Valenzuela G (1978) Theories for the interaction of electromagnetic and oceanic waves-a review. Bound Layer Meteorol 13: 61–85
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© 2006 Springer-Verlag Berlin Heidelberg
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Gade, M. (2006). On the imaging of biogenic and anthropogenic surface films on the sea by radar sensors. In: Gade, M., Hühnerfuss, H., Korenowski, G.M. (eds) Marine Surface Films. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-33271-5_18
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DOI: https://doi.org/10.1007/3-540-33271-5_18
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-33270-1
Online ISBN: 978-3-540-33271-8
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