A new calibration facility at the National Institute of Standards and Technology will boost the accuracy of remote sensing instruments used in global warming and climate research.
The new Facility for Advanced Radiometric Calibration (FARCAL), established by the Optical Technology Division of NIST's Physics Laboratory, will improve the accuracy of data that will shape future environmental policy. It also will boost the accuracy of remote sensing for defense and industrial applications and resource management.
``Research in global warming is ultimately aimed at formulating new government policy and regulation that will impact the U.S. economy through many industries, such as chemical, recreational and building. Accurate estimates of the uncertainties will be critical to the decision-making process,'' says NIST physicist Carol Johnson.
NIST developed the facility in response to NASA's request for assistance in assessing the reliability and comparability of measurements made on a number of different radiometers. ``As the nation's standards laboratory and a non-regulatory agency, NIST is the only institution in the United States that can fulfill basic requirements for these applications,'' Johnson says.
NASA places radiometers on board Earth-orbiting satellites to gather data for climate and environmental studies. Radiometers are able to measure subtle changes in the amount of light at different wavelengths. Most are designed to measure the wavelengths of infrared and visible light, and can determine temperature based on radiated light.
From radiometric measurements, scientists can determine the presence of different elements or chemical reactions. Such data can indicate physical or chemical trends in the atmosphere, within oceans and on land.
In addition to assessments of Earth from space, radiometers are used in high- altitude aircraft by the Department of Defense and in examinations of the ocean and coastal regions by ships or undersea buoys. They also are used in deserts and polar regions to study environmental conditions. A national radiometric standard enables users to trace the accuracy of their data to a single source, NIST. This allows researchers to compare more reliably data collected with different instruments in different parts of the world.