Stellwagen Bank National Marine Sanctuary - Synthetic Aperture Radar (SAR) Imagery

This geodatabase contains Synthetic Aperture Radar images (SAR), which consist of a fine resolution (12.5-50m), two-dimensional radar backscatter map of the roughness of the ocean surface. The interaction between the SAR pulse of microwave energy---X-band (3cm), C-band (6cm) and L-band (24 cm) ---and the ocean surface is complex, as it is dependent on wavelength, polarization, geometry, environmental conditions and the electrical properties of the oceans surface. Ocean features commonly seen on SAR imagery include surface waves, mesocscale ocean circulation structures such as eddies and currents, oily slicks and surface manifestations of ocean dynamics present below the surface, including internal waves and currents passing over shallow shoals. NAMING CONVENTION: The naming convention of the imagery is as follows: SAR_Year_JulianDay_Month_Day_Time(in GMT)_Scene#So for example, SAR_1997_134_5_14_T223315 would read as SAR imagery taken on May 14 (JulianDay 134), 1997 at 22:33:15 GMT time.

These SAR images were obtained from NOAA/NESDIS to support the biogeographic assessment of Stellwagen Bank National Marine Sanctuary. More specifically, the images were used to map the temporal and spatial variability of internal waves in Stellwagen Bank National Marine Sanctuary. Internal waves occur in regions where relatively strong currents flow over bottom topography that protrudes up into the pycnocline. Internal waves appear as packets or groups of waves characterized by: 1) Alternating bands of bright and dark bands; 2) Curvilinear wave crests (bent by refraction); 3) Decreasing wavelengths from front to back of each packet (indicating that nonlinear wave dispersion is in effect and also indicating propagation direction); 4) Decreasing wave amplitudes from front to back of each packet; 5) Wave packets propagate parallel to significant isobaths

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Jackson, C.R. and J.R. Apel. 2004. Synthetic Aperture Radar Marine User's Manual. NOAA NESDIS: Washington, D.C. pp. 464. Available from: http://www.orbit.nesdis.noaa.gov/sod/mecb/sar/sarmanual.html

These data were prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data have been used by NOAA, no warranty, expressed or implied, is made by NOAA as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by NOAA in the use of these data or related materials. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA can not assume liability for and damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

Please contact the Stellwagen Banks NMS Research Coordinator for additional information on data access (david.wiley@noaa.gov);

Contact NOAA Satellite and Information Service, National Environmental Satellite, Data, and Information Service (NESDIS) for imagery acquisition.

Contact NOAA Satellite and Information Service, National Environmental Satellite, Data, and Information Service (NESDIS) for use constraints.

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