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Boulder

NIST USNO 2024 Archive

UTC (USNO) - UTC (NIST) The United States Naval Observatory (USNO) and the National Institute of Standards and Technology (NIST) make...

NIST UTC 2024 Archive

UTC - UTC (NIST) The deviation of UTC(NIST) from UTC has been less than +/-100 ns since July 6, 1994. The table below shows values of UTC -...

FireLiDAR

Light Detection and Ranging (LiDAR) is a powerful tool to precisely measure and track the surface geometry of solid objects. However, in...

Management Resources Leadership

Del Brockett Del Brockett is the Associate Director for Management Resources for the U.S. Department of Commerce's National Institute of...

About Us

Management Resources is committed to providing comprehensive institutional support services that enable NIST and its organizational units to...

ACMD Seminar: Calibration and Verification of Expensive Chaotic Models; Short Runs, Ensembles, and Approximate Gradients

Expensive chaotic models, like those used in weather simulation, present a unique set of challenges for tasks like validation and calibration. Often, they are computationally expensive, highly sensitive to parameters, and are written in languages that don't support approaches like automatic differentiation. This talk will provide an overview of approaches that employ ultra-short runs and ensembles to address these challenges with a specific focus on methods to detect unwanted changes in large model codes.