procedures aboard the ships by D~2 days, helped project personnel install the film badges by
D-1 day, and helped project personnel recover and process the film badges after shot parti-
cipation.
The GITR’s were started either manually at H-3 hours or by receipt of radio timing signals
at H~5 minutes. The majority of the GITR recording units operated for 12 hours, but three
GITR recording units per ship operated for 60 hours. As soon afterward as was feasible, the
record tapes were recovered and processed for data reduction.
2.4
DATA REQUIREMENTS
As pointed out in Section 1.2, the doses and dose rates presented in this report, in units of
randr,hr, are defined in terms of air ionization and not in terms of biological effects.
2.4.1 Data Obtained by Project 2.1. The data obtained by this project consisted of GITR
records from the various stations indicated in Figure 2.3 and of film badges exposed in locations indicated in Figures C.1 through C.19. The measured GITR data consisted of pulses
(representing predetermined quantities of air ionization) recorded on magnetic tapes running
at constant speed. The observed film-badge data consisted of the optical densities of the developed film areas originally under the lead strips.
2.4.2 Data Reduction. The pulses recorded on the GITR magnetic tapes were initially converted to uncorrected dose or dose-rate data by means of an analog data-reduction apparatus
supplied and operated by Project 2.3 (Reference 7); however, the I3M-704 computer at the EPG
was eventually utilized for more accurate read-out. In both cases, the conversion to uncorrected dose and dose rates was based upon the biased field-calibration dose increments of 0.243 mr
per pulse for the low-range GITR detectors and of 0.243 r per pulse for the high-range GITR
detectors.
.
For the IBM read-out, the pulses from the GITR records (entered via an auxiliary specialpurpoSe magnetic-tape unit and gate chassis connected to the computer) interrupted accumula-
tion of constant-frequency timing signals in a register of the IBM-704.
These times between
GITR pulses were stored in the computer memory and a Simplified computer program was used
to convert the stored period information into records of uncorrected doSe, uncorrected doserate, and time after start of computation. Corrections for GITR recorder speeds, determined
by checking the record’s timing channel, were applied as part of the IBM computer program.
Corrections for GITR calibration shifts and bias, discussed in Appendix B, were applied to the
read-out data.
Conversion of time scales from time-after-start-of-computation to time-after-shot was
straightforward for data from the radio-started GITR’s, because the starting pulse on the record also served to start the IBM computation. That was not the case for the manuallystarted
GITR records; therefore, the dose-rate data from these records (plotted on a relative time
scale) had to be time-correlated with data from the radio-started GITR’s. This was accomplished by lining up times of those prominent curve features (such as maxima, and the like)
that should have occurred at the same time for al) stations aboard one ship.
Corrected dose and dose-rate data for individual GITR stations were tabulated. The data
from the washed weather-deck GITR stations were averaged and tabulated. For the periods
during which-saturated GITR’s created gaps in the data, estimates of average radiation data
for the weather-deck areas were approximated by normalizing appropriate data from several
unsaturated interior GITR’s to fit the actual weather-deck data on both sides of the gap. The
averaged weather-deck dose rates were also corrected for decay to serve as a guidein estiMating the relative importance of remote-source radiation (Section 3.2). Ratios of dose and
dose rate in compartment to average dose and dose rate on washed weather decks were calcuated as functions of time. Ratios of the dose rate in the adjacent water to average dose rate
18