Forward Scatter

My father, Wesley B. Harding, came to Antarctica for the 1963-1964 season.  Over a three-month period he supervised the construction of antennas and installed electronic and radio equipment he had designed and built, all to be used as part of the Antarctic Forward Scatter Radio Propagation Network. The network consisted of four transmission paths in an odd, zig-zag pattern across the Antarctic continent. One path led from McMurdo Station to the Russian base at Vostok. The American Byrd station was the origin for two paths, one to McMurdo and one to the South Pole Station. From the South Pole Station a path led to the British Station at Halley Bay.

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Map of the Antarctic Forward Scatter Radio Propagation Network.

At the origin and end point of each path was an antenna and a transmitter (at the origin) and a receiver (at the end point). Dad designed and built those transmitters and receivers. The receiver, in particular, was his original design.

Dad was rated as an Electronic Engineer at the Central Radio Propagation Lab (CRPL) of the National Bureau of Standards, at the Bureau’s laboratory at Boulder, Colorado, where we lived, but he had never graduated High School. Dad dropped out and joined the Marines before he could graduate, probably in 1930 when his father (my grandfather and namesake—I am the third Benjamin Lee Harding in the family line) died.

Dad got his GED when he volunteered for service during World War II, and was trained to be a radio operator, on B-25 light bombers, first doing anti-submarine patrols off the East Coast, and later flying missions with Claire Chennault’s 14th Air Force, the Flying Tigers, in Kunming, China. (I’ve heard stories from his friends of that time that led me to believe that he might have been involved in setting up the radio network that became the Jing Bao early warning network; Dad told me at one point that he was in the OSS, and he was not one to exaggerate or falsify.) In the Army Air Corps, Dad turned a hobby of building radios, something he had pursued from childhood, into a profession.  Following the War he worked first at the Naval Gun Factory, in Washington D.C. and then transferred to the Bureau of Standards, which is what brought us to Boulder.  At the Bureau, he earned the profound respect of his colleagues, all with college educations and many with advanced degrees, for his knowledge, creativity, technical skills and work ethic.

Forward scatter of radio waves occurs when the signal passes through a large number of small irregularities in the ionization of the atmosphere, much like how light is scattered by many small water droplets in a fog. Somehow, and that’s the limit of my understanding, one can make inferences and estimates about the number and energies of cosmic rays from the nature of the forward scatter. The four paths of the Antarctic Forward Scatter Network were designed to make estimates of the cosmic ray “flux.” The antennas of the network were designed to “focus” on an area of the atmosphere about 85 km above the earth at the midpoint of the path. This altitude was favorable for sensing the flux of cosmic rays originating from the Sun.

The International Years of the Quiet Sun (International Quite Sun Year, IGSY) followed on the success of the International Geophysical Year (IGY, “Iggy”) in 1957, an unprecedented international effort to study the Earth in all its aspects. IGY was timed to coincide with a “solar maxima,” a year of maximum solar activity, and in this respect it was a great success. The Sun cooperated, with the highest number of sunspots ever recorded over the two centuries since the procedure for counting sunspots had been standardized. Even as IGY was underway, some scientists came to the realization that certain observations would be valuable during a solar minima. This led to IQSY and the development of the Antarctic Forward Scatter Radio Propagation Network.

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Scientists at the CRPL, along with scientists from the Bartol Research Foundation, conducted the forward scatter cosmic ray research. Among the scientists was D. K. Bailey who first discovered the atmospheric forward scatter phenomenon. (At the time of IQSY, the Central Radio Propagation Laboratory was so well known that it would be referred to in technical publications only by its initials.)

The IQSY forward scatter network was located in Antarctica because the nature of the Earth’s magnetic field at the poles presents much less impediment to the entry of cosmic rays than at non-polar locations. This made the experiment more effective, but made logistics much, much more difficult. Dad and his co-worker, Milton “Woody” Woodward, left the U.S. on December 16. They left McMurdo for the South Pole on January 2, 1964, where they installed the first two systems in ten days. They began work at Vostok on January 12, left Vostok for Byrd Station on January 23 and left Byrd for McMurdo on February 2. They departed the Antarctic continent on February 21. (The British handled antenna construction and equipment installation and calibration at Halley Bay.)

It is remarkable what they were able to accomplish in about ten days at each station. At McMurdo, South Pole and Byrd they had to install two antennas, each on two steel towers, along with two electronic systems. At the South Pole, the transmitting antenna for the Halley Bay path was 177 feet tall, at the time (and perhaps still today) the tallest structure ever constructed in Antarctica. (The antenna design called for a height of 217 feet, but this was reduced because of concerns about safety. As the photo below shows, 177 feet is plenty tall.)

High on the transmitting antenna at Byrd or South Pole.  Climbing one of these, much less building it, took tremendous skill and nerve.  Dad greatly admired the Navy Seabees who built the antennas.

High on the transmitting antenna at Byrd or South Pole. Climbing one of these, much less building it, took tremendous skill and nerve. Dad greatly admired the Navy Seabees who built the antennas.

What else was remarkable about this program was the cooperation with the Russians at Vostok—keep in mind that this was only two years eight months since the failed Bay of Pigs Invasion, and only fourteen months after the Cuban Missile Crisis. Dad came back and told me “We don’t have a bitch with those people, they are the nicest people on earth.” This has remained to me testimony to the power of people-to-people contact. (I was fortunate enough to visit the Soviet Union in August, 1989, and had the same experience.)   Dad admired the Soviet over-the-snow equipment, but their pilots did not have adequate sunglasses, so he gave his Navy-issue Ray Ban Aviator sunglasses to one of the Soviet Pilots.

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Soviet over-the-show transport equipment at Vostok

Today, Christmas Day in the U.S. I called my sister Becky and my wife on a satellite telephone–the quality of the connection is superior to a normal cell phone call. Becky and I reminisced about talking to Dad over a shortwave radio, and once over a phone patch to a shortwave radio connection. Today I am posting this over the internet, and balloons with sophisticated solid state cosmic ray sensors are being launched from near McMurdo and flying circumpolar orbits at altitudes of more than 100,000 feet. Dad died in 1993; he would have loved seeing how far technology has progressed.

The Navy Seabees of U.S. Naval Construction Battalion MCB#8, Operation Deep Freeze, 1963-1964:

J.T. Burleigh, SWC, Chief-in-Charge; E. Grove,CE2; E.M. Knapp, SWCN; E. Lusher, SWCN; D. Harmon, BUL3; P.Whitty, SW2; P. Taylor, SW3; T. Hickman, BUCN; G. Davis, SW3; R. Hobbs, PH2, and Commander George Hoffman.  The Seabees were acknowledged by Dad and Woody in the technical report for “…their capable and efficient erection of all the antenna towers under the most difficult environmental conditions.”

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A Navy Seabee.

A Navy Seabee.

The Navy Seebee tower erection crew and the CRPL engineers.  Dad is third from the right in the bottom row, holding the corner of the flag.  Probably at South Pole.

The Navy Seabee tower erection crew and the CRPL engineers. Dad is third from the right in the bottom row, holding the corner of the flag. Probably at South Pole.  Woody Woodward is to Dad’s left.

Here are some more photos Dad and Woody Woodward took during their trip. After I return to McMurdo I will attempt to duplicate some of these photos and will post the results.

 

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