eee FSH. i qaaantan" ws NATIONAL MILITARY ESTABLISHMENT ARMED FORCES SPECIAL WEAPONS PROJECT P.O. BOX 2610 WASHINGTON, D.C. ADDRESS REPLY To: ALC) 4p a ed THE CHIEF, ARMED FORCES SPECIAL WEAPONS PROJECT SPRD/5/380.01.1 7 November 1949 Mr. Charles L. Marshall Division of Public and Technical Information U. S&S. Atomic Energy Commission 1901 Constitution Avenue Washington 25, D.C. Dear Mr. Marshell: Reference is made to your telephone conversation of this date with Major John Gulley, AFSWP, concerning the classification of the Scientific Meteorological Report on the Visible Atomic Clouds = — Operation SANDSTONE. This report has been classified Secret - Restricted Data by Mr. Herbert Miller, Los Alamos Classification Officer for Operation SANDSTONE. By application of the Joint NME-AFC Classification Guide, it is the opinion of thi: headquarters that the report may be disseminated as Type "B" Restricted Data. Your attention is invited to Sections 4b, 4c, and 4f of the Guide. We believe these sections are applicable to all the phenomenology information contained in the re- port and normally such information is classifiable as Confidential However, the report discloses the exact times of the detonations which require a classification of Secret = Not Type "B" Restricted Data. Restricted Data in accordance with Section 2c of the Guide. With your concurrence, this headquarters proposes to disseminate the report with a classification of Secret = Type "B" Restricted Data. A copy of the report will be forwarded to you under separate cover. Your comments and concurrence will be appreciated. Declassified by DNA, Chief, ISTS ate Sincerely yours, je ff%¢ ff#4 ccs Mire He I. Miller Sites! wae rhate eae ahh oy ay CA G GSAACEO aa pi he f