Work at the observatory was classified during WWII because of its value in predicting radio disturbances from the study of the corona. "The wartime work of the observatory was done under the auspices of the Navy, although overall direction remained in the hands of Harvard.” Post WWII, The National Bureau of Standards contracted the observatory for reports on solar activity. In 1946, CU Boulder became a joint sponsor with Harvard of the observatory, while the Central Radio Propagation Laboratory (CRPL) of the NSB funded HAO's operational costs. The headquarters of HAO was moved to Boulder in 1947.