The scurcos which aay obecure background seam rement. for correction are skyshine and sea activity. The proper application of shielding et the survey instrument could eliminate substantially lars neee Semmensn t measurements. all radiation originating in andi on the aircraft. REFERMICES 6. Automatic fisstor product dust measuring instruments should be perfected and utilised at atations within three hundred niles of the teat area. Radioactive Debris From Operation ivf, 3%0-u522, April, 1952. Te A contiming effort should be made to correlate fallout density 2. Radi. .ctive Debris Prom Qperation CASTLE: sorliwida Pallcst. Sto be released) per unit ares of grount with radiation intensity. Saspling by gumed film or equivelert should be done at monitoring stations. The succeasful measurement +f fallout over the open sea from air- craft hes been demorstrsted.) Perfaction of this: technique holds great promise for accurete evaluation ¢f fallout patterns up to two to three tundred ailes downeind from megaton range bursts. Although the aertal survey program described herein was not desiged for that particular service, the programs could be coordinated for mitual & nefits 3, Atoll radiation data would supplement the sea surface data, broadening the scope of the study. C. Under suitable circumatarces, the atoll data would provide. a direct relation between ses masurments and ground activity. D, Immediate exact kiowladge of the fallout path direction, derived from sea mirfaae measurements, wuld be useful in anticipatingappropriate atoll surveyrequirements. Se The Effects of Atoric Weapzas (Page 255). } 9. The conversion of radiation measurement fro the air to ground intensity should be more sccuretely derined. Phenomencn necessary to be . pete x ete rhe eee ae studied are inatrumental energy depermdense, effects of fisaion product age and caomesition, ani the relationship of ground intensities as deternined by air measurement. to ground intensity mexsuracent dy conventional portable survey instrumonts. 10. Recommendations concerning instrumentation are included in Sect fon VW. ’ J - “1 , | I xs a1 ‘ = could be avoided in this asnnor.e Survey Instrument Characteristics Measured by EadL, Instraconts Branch staff, - survey functionge Wasteful overlapping of survey miselona be o Survey sircraft enroute between two atolls can meaqure sea radiation az a corollary xission. Toward this end, survey patterns could bse modified within certain limits to examine areas of particular interest without impairing the atoll Radioactive Detris Fro~ Operation CASTLEs aerial Survey of O7-n Sea Following YiebelSciaAag, ULOW618. itgenscanica A. 3. 3 8. -