EOS Validation Program

Institution: National Renewable Energy Laboratory
                    Center for Renewable Energy Resources
                    1617 Cole Blvd, MS 3411
                    Golden, CO 80401-3305
Phone: (303) 384-6768
FAX: (303) 384-6790
E-mail: daryl_myers@nrel.gov

Naif Al-Abbadi, Assistant Director, Energy Research Institute, Kingdown of Saudi Arabia

June 2001
Final Report, February 2003

The National Aeronautics and Space Administration (NASA) needs measurements of radiation fluxes and atmospheric aerosol optical depth at the Earth's surface to supplement and enhance data product validation activities for their Mission to Planet Earth (MTPE) satellite data. Data for desert regions around the world are needed by the Clouds and Earth Radiant Energy System (CERES), Multi-angle Imaging Spectrometer (MISR), and the Moderate Resolution Imaging Spectrometer (MODIS) Atmosphere and Land MTPE validation teams. The National Renewable Energy Laboratory (NREL) and King Abdulaziz City for Science and Technology (KACST), located in Riyadh, Kingdom of Saudi Arabia, will provide quality assessed surface radiation data from an existing twelve station network in the Kingdom of Saudi Arabia to these teams. Using Saudi funds to purchase and install instrumentation, one Saudi monitoring station will be upgraded to meet World Meteorological Organization (WMO) Baseline Surface Radiation Network (BSRN) specifications in instrumentation, data acquisition, and reporting. Since 1993, NREL has assisted KACST to purchase, characterize, calibrate, install, and operate state-of-the-art solar radiometric sensors for direct beam, total hemispheric, and diffuse solar radiation calibrations and measurements. NREL has developed solar radiation measurement quality assessment software to quantify data quality and quickly diagnose instrumentation problems. NREL has been actively participating in the U.S. Department of Energy Atmospheric Radiation Monitoring (ARM) program and the WMO BSRN program, and is aware of the need for high quality radiometric and aerosol optical depth data of known accuracy. Aerosol optical depth and total column water vapor instrumentation and retrieval algorithms have also been developed at NREL. KACST and NREL are investigating ways to correlate and derive surface radiation flux from satellite data, and account for the impact of aerosol optical depth and water vapor on atmospheric transmission. Comparison of independently derived NASA and NREL/KACST surface radiation fluxes will assist project participants in evaluating the uncertainty in and improving the accuracy of satellite derived products.