CoastWatch WCRN Dataset Summary

		Dataset Summary
West Coast Regional Node

Diffuse Attenuation Coefficient at 490nm Wavelength (K490)

Program: NASA Earth Observing System
Spacecraft: Aqua
Sensor: Moderate Resolution Imaging Spectroradiometer (MODIS)
Data Stream: Direct Broadcast
Primary Geophysical Parameter: Diffuse Attenuation Coefficient
Nominal Accuracy: unknown
Spatial grid: 0.0125 degrees longitude by 0.0125 degrees latitude, geographic
Spatial coverage: West Coast of North America
Temporal Coverage: February, 2006 - ongoing
FGDC Metadata

Short Description:
CoastWatch provides diffuse attenuation coefficient data at 490nm wavelength from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. These data are received and processed by the College of Oceanic and Atmospheric Sciences (COAS) at Oregon State University. The diffuse attenuation coefficient is a good measure of water clarity. This is an EXPERIMENTAL dataset and is distributed for scientific evaluation.

Technical Summary:
CoastWatch offers diffuse attenuation coefficient data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on NASA's Aqua satellite. Additional information on the Aqua satellite, the MODIS sensor, and NASA's Ocean Color projects can be found on NASA's OceanColor Web.

This data is downloaded via direct broadcast to a receiving station at Oregon State University (4-6 satellite passes per day). Oregon State University's College of Oceanic and Atmospheric Sciences (COAS) handles the receiving and processing of MODIS data. Data are processed with NASA software using methods developed by the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS). Raw satellite data are processed to diffuse attenuation coefficient according to Mueller, 2000.

Data is made available at 1.47 km resolution for the West Coast region. The data are mapped to an equal angle grid of 0.0125 degrees latitude by 0.0125 degrees longitude for the West Coast of North America. The mapping uses simple arithmetic means to produce single-pass and composite images of various duration (1,3,8, and 14-days).

Disclaimer:
Despite our best efforts, incorrect data may often appear within near real time data sets. NOAA CoastWatch accepts no liability for use of these data products. It is recommended that these products NOT be used for navigation.

Acknowledgement:
If this data is used for presentation or publication, please acknowledge the NOAA CoastWatch Program, NASA, and Oregon State University's College of Oceanic and Atmospheric Sciences.

References:
Mueller, J.L. 2000: SeaWiFS algorithm for the diffuse attenuation coefficient, K(490), using water-leaving radiances at 490 and 555 nm. In O'Reilly, J.E. and co-authors: SeaWiFS Postlaunch Calibration and Validation Analyses, Part 3. S.B. Hooker and E.R. Firestone, Eds., NASA/TM-2000-206892, Vol. 11, NASA Goddard Space Flight Center, Greenbelt, Maryland, 24-27.

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