We demonstrate the use of a high‐precision ground‐rotation sensor to subtract wind‐induced tilt noise in a horizontal broadband seismometer at frequencies above 10 mHz. The measurement was carried out at the LIGO Hanford Observatory using a low‐frequency flexure‐beam‐balance with an autocollimator readout and a T240 seismometer, located in close proximity to each other. Along their common horizontal axis, the two instruments show significant coherence below 100 mHz, which increases as a function of wind speed due to floor tilt induced by wind pressure on the walls of the building and the ground outside. Under wind speeds of 1015  m/s, correcting the seismometer for measured ground rotation lowered the signal by a factor of 10, between 10 and 100 mHz. This article describes the instruments used, shows representative data for low and high wind speeds, and discusses the tilt subtraction and possible limitations.

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