condition.
Seweral standard relations for Py a?yr Ry and iw tuve been >
lished; the TM Probles wT for theoretical blast-vave calculations, as smarized by Broyles!® has been used here as a cocvenient reference stantard
out to 9000 feet frea a l-xiloton free-air burst.
overpressure is 0.37 psi.
At this ranze, incizest
Beyond this range, it is assumed Chat overpressure
decays in proportion to range, pts?
This nonacoustic decay exponent uzs
found by experizent at Sandia with l-pound high explosives in June 166] ani
verified by prelisioary analysis of Project Banshee data.
The latter experi-
ment was with 500-pound pentolite spheres, exploded near 60,000 feer MSL over
White Sands Missile Range, New Mexico, in the sumer of 1561.
Reports and
references for these test results are not yet published.
Ambient atmospheric conditions at various altitudes observed by the JIF-7
weather service radiosonde balloons are shown in Tables 6.5 and 6.6.
Early
ealculations were made with an upper atmosphere model suggested by analysis
of sounds refracted back to ground from the ozonusphere from several atomic
test operations. 9 ‘This model now seems to be inaccurate and is no longer used
However, differences between the atmospheric model and standards presented by
the Rocket Pane1!* or by the apoc, 19 as shown in Table 6.7 and used bere, do
mot greatly influence the calculations in this report.
The ground-reflected overpressure recorded on Johnston Island from Tesk
and Orange would be observed from a l-mt surface burst at ranges shown by the
sealed curve in Fig. 6.1.
Since Johnston Island air pressure was 1013 =b,
(pofe)'/3 z= 1 ws (1 st)(R/R,)3; for Teak, R = 250,230 feet, and for Orange,
R = 197,713 feet.
Three significant overpressure values from each sbot hive
been used to infer the apparent yields shown in Table 6.8.
Calculated arrival tines at Johnston Islaod in Table 6.8 were obtained by
wodified Sachs scaling to pressures and shock speeds at approximate 10,000-fou
intervals along the line from burst to recorder.
Calculated tines are close t
observed values shown previously in Tables 6.1] and 6.3.
Tize of arrival at Te
GZ is 190.14 seconds, - 0.02 second, nearly the same as at the recorder.
Ora:
however, was at an appreciable horizontal range, and CZ tise of arrival sax bw
estizated froma the 166.71 seconds observed at zase CH-1, to give the deat esti
mate as 103.1] seconds.
In view of the many accimnrinne ade in whie ralentaes
this GZ tise of arrival may easily be in error by seconds.
Ey