Doppler, the thirteenth full-scale nuclear test in the summer 1957 Nevada series, was detonated at 5:30 a.m. today from a 1500-foot balloon in Yucca Flat. The experimental device was designed by Los Alamos Scientific Laboratory.

There were eight experiments on the sequence timer. Ten civil effects experiments and four military effects experiments were conducted

Four hundred and fifty military observers viewd the shot from trenches at approximately 3,000 yards from ground zero. Included in the group was a platoon ofCanadian troops here to participate in the Army exercise to be conducted in connection with the Smoky shot. Twenty-five military observers viewed the shot from an observer area. Forty-one aircraft participated.

The detonation was heard as a very sharp bang at the Control Point, followed by prolonged rumbling. It was heard as bangs and rumbles at Bishop and Inyoyern, and as rumbles at St. George and Tonopah.

The cloud rose to 36,000 feet, and soon broke away from the stem and began moving in a general norty-northwesterly direction. The stem is settling back to earth within the Test Site. It is anticipated that only traces of fallout will be recorded off the Bombing and Gunnery range.