Document Details


Title:
OPERATION REDWING - PROJECT 6.4, AIRBORNE ANTENNAS AND PHOTOTUBES FOR DETERMINATION OF NUCLEAR - WEAPON YIELD (DELETED)
Author(s):
Subject Terms:
REDWING PROJECT; FISSION YIELD; THERMAL RADIATION; RADIATION DETECTION; ELECTROMAGNETIC RADIATION; EQUIPMENT; MEASURING INSTRUMENTS; PHOTOTUBES; DAMAGE; RECOMMENDATIONS; FIREBALLS; IONOSPHERE
Document Location:
Location - NNSA/NSO Nuclear Testing Archive Address - P.O. Box 98521 City - Las Vegas State - NV Zip - 89193-8521 Phone - (702)794-5106 Fax - (702)862-4240 Email - CIC@NV.DOE.GOV
Document Type:
REPORT
Publication Date:
1959 Aug 07
Declassification Status:
Sanitized
Document Pages:
0142
Accession Number:
NV0051365
Document Number(s):
WT1352EX
OpenNet Entry Date:
1994 Aug 26
Description/Abstract:
A NUCLEAR DETONATION GENERATES THREE CATEGORIES OF CHARACTERISTIC PHEN OMENA WHICH CAN BE MEASURED FROM A HIGH-SPEED AIRCRAFT: (1) LOW FREQUE NCY ELECTROMAGNETIC RADIATION WHICH CAN BE RECEIVED BY AN ELECTRIC OR MAGNETIC ANTENNA; (2) THERMAL RADIATION DETECTABLE BY PHOTOTUBES; AND (3) PICTORIAL CHARACTERISTICS WHICH CAN BE PHOTOGRAPHED. AIRBORNE EQUI PMENT HAS BEEN DESIGNED FOR DETERMINING THE LOCATION AND YIELD OF A NU CLEAR DETONATION. THIS EQUIPMENT FOR INDIRECT BOMB DAMAGE ASSESSMENT ( IBDA) DETERMINES YIELD FROM A MEASUREMENT OF THE INTERVAL BETWEEN THE TIME OF THE BURST AND THE TIME OF THE SECOND PEAK IN THE THERMAL RADIA TION INTENSITY CURVE. FLUSH-MOUNTED FERRITE-CORE MAGNETIC LOOP ANTENNA A, FOR USE IN DETECTING THE ELECTROMAGNETIC SIGNAL AND THUS FIXING THE TIME OF BURST, PERFORMED SUCCESSFULLY DURING OPERATION REDWING. TWO K INDS OF PHOTOTUBES FOR DETECTING THE SECOND THERMAL PEAK WERE TESTED A ND WERE FOUND ABOUT EQUALLY SATISFACTORY. THE METHOD SELECTED FOR YIEL D DETERMINATION GAVE RESULTS ACCUATE TO 16 PERCENT FOR FIVE SHOTS WITH YIELDS IN THE RANGE TO 5.0 MT. A DETAILED STUDY OF THE COLLECTED DATA SHOWED THAT THE ELECTROMAGNETIC SIGNAL, CONSISTING OF A DIRECT PULSE FOLLOWED BY A SERIES OF IONOSPHERE-REFLECTED SKY WAVES, COULD BE USED IN MANY WAYS TO GIVE INFORMATION CONCERNING THE DETONATION AND THE ION OSPHERE. FROM THE TIME INTERVALS BETWEEN THE GROUND WAVE AND SKY WAVES IT WAS FOUND POSSIBLE TO COMPUTE BOTH THE DISTANCE BETWEEN BURST AND RECEIVER AND THE HEIGHT OF THE REFLECTING IONOSPHERE LAYER. FROM THE O SCILLATORY PERIOD OF THE INDIVIDUAL SKY WAVES OR GROUND WAVE THE YIELD COULD BE ESTIMATED. THE WAVE FORM OF A SKY WAVE COULD BE USED FOR AN ESTIMATE OF THE HEIGHT OF THE RECEIVING EQUIPMENT. THE AMPLITUDES IN A SEQUENCE OF SKY WAVES COULD BE USED TO GIVE THE RADIAN FREQUENCY CHAR ACTERIZING THE IONOSPHERE, AND TO EXTRAPOLATE TO THE AMPLITUDES OF OTH ER SKY WAVES OR THE GROUND WAVE. FOR A NUMBER OF TEST SHOTS, THE THERM AL RADIATION INTENSITY DATA WAS COMPARED WITH THE EXPECTED IRRADIANCE TO GIVE ESTIMATES OF ATMOSPHERIC ATTENUATION DUE TO CLOUDS AND HAZE. M EASUREMENTS OF AMBIENT LIGHT INTENSITY AND OF THE VARIABILITY OF AMBIE NT LIGHT WERE ALSO MADE, TO AID IN THE EVALUATION OF THE IBDA SYSTEM. ON THE SEQUENCE PHOTOGRAPHS THE POSITION OF THE BURST COULD BE DETERMI NED FROM: (1) THE INTERSECTION OF BRIGHT RADIAL LINES; (2) THE CENTER OF SYMMETRY OF THE CONDENSATION DOME (SEE BELOW); (3) THE FIREBALL ITS ELF; OR (4) THE STEM OF THE NUCLEAR CLOUD. WHEN THE FIREBALL WAS VISIB LE, ITS RADIUS COULD BE USED AS A MEASURE OF YIELD, PROVIDED THAT THE TIMING OF THE PICTURE AND THE RANGE BETWEEN BURST AND CAMERA WERE KNOW N. THE CONDENSATION DOME, PRODUCED IN HUMID AIR BY THE RAREFACTION PHA SE OF THE SHOCK WAVE, APPEARED IN ALL BURST SEQUENCES AND WAS FOUND US EFUL IN DETERMINING A ROUGH VALUE OF THE RANGE AND OF THE TIME OF THE BURST RELATIVE TO THE TIMING OF THE PHOTOGRAPHS.


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