POST-CASTLE SECURITY ZONE Lf Sa™~ AREA GREEN ' t 159 | oO TAONGI | 1 AREA EVELYN , ENEWETAK CQ Lo a SS BIKA R a | RONGELAP | |BiKINI | 1g? | | PRE-CASTLE SECURITY ZONE or >" AILUK TRonGerRIK ° i og Nee UJELANG ® / LIKIEP SQ\ewauscenn Q L 100 | 300 | ; NAUTICAL wr 185 , 5° F 3 556 KILOMETERS L TSSPE 160° Figure 16. 165° i 170° 1759 Pacific Proving Ground search areas and secur]yty zones for Operation CASTLE. Fallout predictions were based on weather observations andfon the results of previous operations, primarily those in Nevada, for witich the most data were available. Two types of analyses of weather-wigd data were used in preparing the fallout predictions: hodographs and trajectory fore- casts of the paths that would be assumed by particles falling grom a given height through the various wind layers. HODOGRAPHS. A hodograph is a plot of wind speeds and direqtions. presents a vector diagram representing the horizontal projectidn of the Path of a wind-sounding balloon rising in the atmosphere at a rate. gonstant The hodograph may also be considered to represent the hdrizontal 109 It