The official order that handed over the "special bomb" to General Carl Spaatz, who was in charge of Air Force operations in the Pacific, allowing him to execute it "as soon as the weather will permit visual bombing
after about 3 August 1945" was signed by Groves,(http://www.
In contrast to World War II high-altitude visual bombing
accuracy that averaged perhaps 2,000 feet in good weather and SAC high-level radar bombing in the early 1960s, that averaged around 1,300 feet, PGMs could get bombs within tens of feet of the target.
was the most accurate, but weather often interfered.