photopanel also gave a direct indication of dose in the cloud. It re- quired only that the mter be observed in the film frames where the marker light occurred. The NBC film packs gave an indirect measure of the dose in the cloud, This was computed by subtracting the return flight dose which was calculated from the T1B decay-rate masurements from the total dose indicated by the film packs, 2.3.4 Dose on Return Flight. The radiation dose on the return flight was measured directly by the PeMeter, Bioscel, and Sigmatron. In each instance all that was necessary was to subtract the dose in the cloud from the total dose. The difference was the dose received on the return flight. TABLE 2,1 SUMMARY OF SOURCES OF REQUIRED DATA Data directly available is indicated by x; dodirectly available is indicated by 0. Infornstion Desired on Each Flight bk . on 218 2 £ g Ssi 4 sf a ii Salis i 4 2/43/8332] 8 Total Radiation Dose x x Zz Time in Cloud x x Dose in Cloud x x x Dose on Return Plight x z x Maximum Dose Rate in x x Average Dose Rate in z zx Dose Rate at Cloud Exit x z Decay Rate on Return x Contamination Factor x Cloud Cloud Flight x x Zz 2 6 0 0 0 0 0 An indirect method of obtaining that portion of the radiation dose received after exit from the cloud and during the return flight was by extrapolation of the decay-rate curve measured by the 715 after the aircraft was on the ground back to cloud-exit tim and integration of the area under the curve from cloud-exit time to tims of landing. 2.3.5 Maxim Dose Rate in Cloud. The maximum dose rate in the 20306 Average Dose Rate in Cloud. The average dose rate in the cloud was taken directly from the P-Meter and Bioscel curves, The pilot also observed the maximm dose rate indicated by the Bioscel meter in the cockpit. cloud was calculated by dividing the dose received in the cloud by the tims in the cloud. Both of these were provided directly by the P-Meter,