ERS SAR observations of long internal waves with positive backscatter signatures

• Type: Article in International Conference Proceedings Book
• Date: 1999

Authors

da Silva, JCB (Author) Other; Ermakov, SA (Author) Other; Robinson, IS (Author) Other; Potter, RCH (Author) Other

Conference proceedings International

Title: International Geoscience and Remote Sensing Symposium (IGARSS)

Pages: 1481-1483

Proceedings of the 1999 IEEE International Geoscience and Remote Sensing Symposium (IGARSS'99) 'Remote Sensing of the Systems Earth - A Challenge for the 21st Century'

Hamburg, Ger, 28 June 1999 through 2 July 1999

Indexing

ISI Web of Knowledge

Scopus - 4 Citations

Other information

Authenticus ID: P-007-8R1

Abstract (EN): A recent classification scheme for synthetic aperture radar (SAR) signatures of internal waves (IWs) has been proposed based on the analysis of ERS-1 SAR images of the Iberian shelf zone. According to this classification IWs which propagate with relatively low phase velocities (Cp approx. 0.5 m/s) display three different signatures depending on the parameters of surface-active films and wind speed. In particular, it is found that at very low wind speeds IWs display single positive backscatter signatures as a result of the image background falling to the noise floor at such low wind conditions. However, in different oceanic regions, we have observed predominant single positive signatures even when the background backscatter is well above the noise level. In this paper we report observations of IW signatures which mainly display positive backscatter variations on a background above the noise level. We seek for a common factor in the variety of observations from different oceanic regions, (such as the Strait of Gibraltar, Andaman Sea, Sulu Sea, Sea of Bali, Gulf of California, etc.) that may lead to an explanation of the phenomenon. One common factor associated with these SAR observations seems to be that they correspond to comparatively long IWs (their wavelength can be up to several kilometres) which are known to propagate with high phase velocities (Cp>1 m/s).

Language: English

Type (Professor's evaluation): Scientific