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Sun Glare at Audi Field

Earlier this year physics undergraduate Brandon Harper began working with ESPN to solve a sun glare problem occurring at the new Audi Field in Washington D.C. During the broadcast of a soccer game last fall, a distracting glare due to the October sunset greatly interfered with the viewing of the game. The goal of the project was to determine when and if the sun could cause more problems like this during future games for the cameras located on the east side of the stadium. From photo and video evidence, the glare last October 13 lasted from about 5:00pm to 6:10pm when the sun finally set below the stadium walls with respect to the cameras. The glare was at its worse at around 5:50pm. The azimuthal and altitudinal coordinates of the sun were determined for that time using Stellarium (Az: 252°16' and Alt: 8°48'), allowing reference to the problematic position when checking dates for the 2019 season. It soon became clear that the azimuthal coordinate may not have an effect on the likeliness of a glare, as the sun will set year-round behind the uniform wall of the stadium, and the camera must be allowed to pan across the entire field. This left an emphasis on investigating the altitudinal coordinate of the sun during its setting. A video of the sunset as viewed from the camera stand was recorded in early March this year, allowing conclusions to be drawn by comparing it to the glare event and using Stellarium to check the coordinates. The problematic altitude of the sun was found to occur consistently about one hour before sunset each day, where the glare could be an issue 1.5 to 0.5 hours before sunset, drawn from the duration of the glare. The conclusion reported to ESPN was that they should be concerned about glare in their broadcast when filming on a clear day anywhere between 90 to 30 minutes before sunset on a given day. The ESPN crew in Washington D.C. was able to take this general rule away from the project and they are applying it to the future of sports broadcast at Audi Field.

Tuesday, April 30, 2019  —  Kevin