Radio age research, manufacturing, communications, broadcasting, television (1941)

TOWERS SIMILAR TO THE ONE ABOVE SUPPORTED TELEVISION CAMERAS AND TRANSMITTERS ON BIKINI. AT right: "drone" plane carrying a television CAMERA, COMES IN FOR A LANDING. OPERATOR IN FORE- GROUND HAS TAKEN OVER CONTROL FROM THE "MOTHER" PLANE IN THE DISTANCE. planes and boats at a distance, ob- servation and recording of the ex- plosions, and their after-effects by television and associated cameras. Time signals were sent out by a radio transmitter and picked up by receivers correlated with the de- vices to be controlled. In this way, camera shutters and numerous measuring devices were activated at certain instants. For example, in order to make a study of the ex- tremely rapid rise in air- and water- pressures during the two tests, it was necessary to run a recording film at the high rate of 800 feet per second. This demanded precise timing which was possible only through the use of radio time sig- nals. Another important project was the observation by radar of the cloud column which followed the blast. This was carried out by in- stalling radar units at various dis- tances from three miles to 200 miles from the blast. Other radar oper- ators trained their beams on the target area in order to check on the anchored ships before, during and after the explosion. Despite the ob- scuring cloud that hid the majority of the vessels for many minutes, it was possible, through radar, to note the displacement of the ships and whether they were badly damaged and in a sinking condition. As the world well knows by this time, it is not possible for humans to live safely within a critical range of intense atomic activity. But radio apparatus could be and was devised to replace human personnel in the danger areas. Scores of high- ly accurate automatic measuring devices were installed on the target ships, on the ocean surface and be- neath the surface. A radio trans- mitter associated with each meter- ing instrument transmitted the readings automatically to labora- tory ships in the observation fleet, where they were received and re- corded automatically. This is called telemetering. Buoys Carried Microphones One of the most interesting uses of telemetering was the installa- tion of a string of sonobuoys a few hundred feet apart, extending out- ward in a straight line from the explosion point. Each buoy carried one microphone above water and another under water. Each sono- buoy transmitter worked on a dif- ferent frequency and the various signals were picked up and re- corded on an oscillograph in one of the instrument ships. There were many other applications of tele- metering but those just cited illus- trate the importance of this tech- nique to the successful conclusion of the bomb tests. To that section of the public which is not technically minded, the uses of television at Bikini un- doubtedly are of major interest. The Pacific tests involved a situ- ation in which television was ideal- ly suited. It was highly desirable to have a close-up view of what hap- pened in the target area while it was happening, but no human eye could be closer than eight or ten miles with safety, and photographic cameras could reveal nothing until their films were developed. How- ever the television camera could be close to the scene—and was. On Bikini Island, two RCA cam- eras were placed on 75-foot towers spaced about a half mile apart and only three miles from the explosion point. In that position, operating unattended, they picked up and broadcast the views that human eyes would have seen had they been on the tropical atoll. Television receivers were in- stalled on seven ships, two were carried in airplanes and one was placed on Bikini. The viewing screen of the latter was focused on a film camera which was started up by radio control signals just before the explosion. The receivers in the planes and some of those aboard the observation ships were also combined with photographic cameras. On one ship, the camera was a special, highly complex in- strument developed by the Naval [10 RADIO ^GE]