Abstract
NASA will be launching complex satellite remote-sensing platforms for monitoring the Earth's radiation budget, land use, and atmospheric physics for periods exceeding ten years. These Earth Observing Satellite (EOS) platforms will strive to detect man-made and natural variations in the Earth's climate. From 1993 to the present (1999), the National Renewable Energy Laboratory (NREL) and the King Abdulaziz City for Science and Technology (KACST) in Riyadh, Saudi Arabia, conducted a joint solar radiation resource assessment project to upgrade the solar resource assessment capability of the Kingdom of Saudi Arabia. KACST has deployed a high-quality 12-station network in Saudi Arabia for monitoring solar total horizontal, direct beam, and diffuse radiation. One- and five-minute network data is collected and assessed for quality. 80 percent or more of the network data fall within quality limits of +/-5 percent for correct partitioning between the three radiation components. This network will provide measured data for validating the NASA remote sensing systems. We describe the network, quality assessment procedures, and the results of estimating aerosol optical depth and precipitable water vapor. These are important for validating satellite estimates of radiation fluxes in and at the top of the Earth's atmosphere. (Author)