WEINSTEIN: EXPLOSIVE SOUND-SOURCE STANDARDS 



in source -level estimates is as high as 7.7 dB. The three data sets 

 also have different spectral shapes. 



The first data set consists of the detailed computation of 

 Gaspin and Shuler (1971) . Although based on experimental data, it 

 does involve the extrapolation of the shock-wave impulse from 

 measurements at deeper detonation depths. These extrapolated values 

 are a good bit higher than those previously used. 



The second data set is provided by Busch (1973) and corresponds 

 to experimental measurements using MILS hydrophones. The system 

 sensitivity is computed, and not measured. Additionally, correc- 

 tions for surface reflections are made during processing, since 

 the reflected signals arrive before the direct signal of shock wave 

 and bubble pulses has died down. 



The third data set is computed using the simplistic forms 

 published by Weston (1960) , which were based on the earlier experi- 

 mental work of Arons and Yennie (1948) . 



Although the uncertainty in source level represented by the 

 spread in these data sets is many times larger than our goal of 

 ± 1 dB, the problem is recognized and it is reasonable to assume 

 that the uncertainty in source level can be significantly reduced 

 by performing carefully controlled experiments. 



SOURCE-LEVEL FLUCTUATIONS 



When measured data are compared to model computations, we 

 would like the data to be free from random variations. To help 

 satisfy this need, the source conditions should be identical from 

 shot to shot. Fluctuation artifacts can arise from variations in 

 shot depth which alter the spectral shape, principally by changing 



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