The Echo

The story of electromagnetic spectrum operations (EMSO) continues with the birth of radar. With wireless communications paving the way, these technologies led to the early use of electromagnetic warfare from World War I through the US entering World War II, following the attack on Pearl Harbor. In this episode, Mr. Ray Chase from the Information Age Learning Center and Mr. Mike Simmons from the National Electronics Museum share the story about early radar development and electromagnetic warfare in the early 20th Century. Since the dawn of the Electronic Age and the years following World War I, new advances came from Marconi’s invention of wireless communications. Radio jamming, direction-finding stations and air-to-ground communications displayed major advantages for reconnaissance. But as we find out in today’s story, these advances would come to serve an even greater purpose in the Second World War.

Speaker 1 (00:02):
This episode is sponsored by BAE Systems, the global leader in next generation, electronic warfare systems. With more than 60 years of experience and 33,000 people as part of its global defense, aerospace and security business, BAE Systems' electronic warfare systems are found on the most advanced military platforms in the US and around the world. Learn more at baesystems.com/ew/

Speaker 2 (00:37):
Welcome to The History of Crows, a podcast on the evolution of electromagnetic spectrum operations or EMSO, and the men and women, the crows, who changed the way we conduct military operations and the way we live around the world. History of Crows will help you navigate the intersection of military history, technology, and scientific discovery through insights and stories from the people and war fighters who know how to fight in the electromagnetic spectrum.

Speaker 2 (01:06):
We take you through the important discoveries, inventions, battles, and developments that make the crow motto true, to be the first in and the last out in any military operation today. The History of Crows is brought to you by the Association of Old Crows, or the AOC, an international professional association comprised of people who are experts in electromagnetic warfare and signals intelligence. To learn more about the AOC, please visit www.crows.org.

Speaker 2 (01:53):
It was the morning of December 7th, 1941. Out in the Pacific, the sun had just risen over Hawaii. On the top of a hill north of Honolulu, there set a building that overlooked the vast expansive ocean and sky before it. It was the Opana radar site. On this particular morning, some operators had come up to the site to practice using radar equipment. At about 7:02 AM, just before they turned off the machines, they heard an echo ping throughout the room. Operators realized that several aircraft were approaching from the north. They were suspicious of it and reported it, but no one was quite sure what this echo was implying and had they understood what they were hearing and seeing, they may have realized much sooner that this sound indicated that Japanese forces were approaching, and an attack was imminent.

Speaker 2 (02:57):
Today, in the echo, we continue the story of electromagnetic spectrum operations and how wireless communications paved the way for the birth of radar. These technologies led to the early use of electromagnetic warfare from World War I through the United States entering World War II following the attack on Pearl Harbor. To tell the story about early radar and electromagnetic warfare in the early 20th century, we hear from Mr. Ray Chase.

Ray Chase (03:23):
This was the start of the army's experimentation with radar.

Speaker 2 (03:29):
Mr. Ray Chase is from the Information Age Learning Center, a non-profit organization located at the historic site of the American Marconi Belmore wireless station, which ultimately became the US Army Camp Evans signal laboratory. We'll also hear again from Mr. Mike Simons from the National Electronics Museum in Linthicum, Maryland.

Mike Simons (03:49):
Now one of the things about those early radars is there weren't very many people who knew how to operate a radar.

Speaker 2 (03:55):
By the time the 20th century had begun, Guglielmo Marconi, and the Marconi Company had globally interconnected the world through wireless communications. The dawn of the electronic age had begun. People were dreaming of all the potential and sharing information across great distances, but tensions were running high. The First World War had begun, wireless communications and radio jamming quickly became critical for military operations. Early in 1914, when the British cruisers Indomitable and Indefatigable encountered German naval ships, the British were able to use jamming and pass without any shots fired. Soon after came the development of direction finding stations, stations that would propel the first large scale use of air power in the great war. Alfred Price, author of the three volumes series, The History of US Electronic Warfare writes.

Alfred Price (04:48):
Early in 1915, the Royal Navy began erecting a chain of direction finding stations along the east coast of England, whose bearings could establish the position of any ship or aircraft using radio in the North Sea area. The stations employed the well known Bellini-Tosi system of direction finding antennas, but their performance was greatly enhanced by a sensitive new type of amplifier using vacuum tubes developed by the Marconi company.

Speaker 2 (05:15):
With each passing year of World War I, new advances came from Marconi's invention of wireless communications, radio jamming, direction finding stations and air to ground communications displayed major advantages for reconnaissance. But these advances would serve an even bigger purpose in the Second World War like Simons explains.

Mike Simons (05:36):
But as the idea of radio progressed into the Second World War, radios became vital to the ability to command and control the aircraft, to coordinate with what was going on, on the ground. So radio had become an essential part of all aircraft, not just aircraft that maybe were being used to spot artillery like in the First World War. And then of course, radio was used for controlling aircraft, flying to airports. So pilots could land when the weather wasn't necessarily perfect. Radio was used to direct fighters to targets after they had been tracked by radio. So the difference between radio from World War I or World War II is vastly significant.

Speaker 2 (06:20):
This difference in how radio technology was used in the two World Wars can partly be attributed to Marconi. In 1922, Marconi received the prestigious Institute of Radio Engineers Award. As he gave his acceptance speech, he said something that caught people's attention. Marconi told them that there was a likelihood and possibility of a technology that could detect ships in the fog. What we now know today as radar. Marconi wasn't the only person thinking in this direction. Others had for many years, especially coming out of World War I, but when Marconi spoke, people listened, and a particular radio engineer decided to move this idea forward.

Ray Chase (07:02):
The year 1922 is important because at the Naval Research Lab in Virginia, Dr. Hoyt Taylor and his assistant, Leo Young were working on a five meter communication systems when they noted that passing ships on a river between the transmitter and receiver were creating disruptions in the radio signals. At this point, Dr. Hoyt Taylor decided that this should be followed up on. And however, he was somewhat constrained by inadequate funding, but he followed up on it and decided that a continuous wave signal was not going to be of much use because it did not give any ... It gave an indication that something was happening off in the distance, but it did not give any direction indication or any range indication.

Speaker 2 (08:08):
Still this marked an important step. Dr. Taylor now knew that not only could radio waves carry information, but the reflection of radio waves could also detect both seen and unseen objects. At first people didn't see this discovery as immediately practical, but they were interested in further study and experimentation of it. After a few years, Dr. Taylor finally made progress.

Ray Chase (08:32):
So by 1925, he had scrounged up sufficient funding to make a pulse transmitter where he could send out a short burst of energy and then wait for a reflected signal to come back, which is really the basis of radar operation. By operating short pulses and waiting during a time period for the echo to return and measuring the distance between the transmitter and the received pulse, received signal.

Speaker 2 (09:09):
Other work using pulse transmitters was taking place at the Carnegie Institute. There, researchers were measuring the altitude of the ionosphere around the world. The ionosphere is the layer of the Earth's atmosphere that contains a high concentration of ions and free electrons. Because of this, it's able to reflect radio waves. These measurements were fundamental in determining the range of an object that would make radar a game changing technology.

Ray Chase (09:35):
So the period from 1922 to the latter part of that decade is really one of the important starting points for the true investigation of radar.

Speaker 2 (09:52):
At this point in the early development of the radar, radio signals moved at relatively low frequencies, but to properly detect and receive a reflected signal from an object, radio signals needed to move higher at frequency. Unfortunately, this meant that the transmitter and receiver had to be a mile apart from each other. This limited the US Navy. So the Navy Research Lab approached the army.

Ray Chase (10:14):
They did show it to a Major William Blair from the army in Fort Monmouth, who had just become interested in creating a detection device, such as that for the army. He understood that he needed to have much higher frequencies to make a radar detection device effective. However, and this was the start of the army's experimentation with radar at Fort Monmouth, New Jersey.

Speaker 2 (10:51):
The US Navy and Army kept working together. Although they didn't always see eye to eye, they both saw potential for the radar detection device, but they had different views on how this new technology could impact their respective missions. Radio detection and ranging became shrouded in secrecy, and eventually led to the acronym radar, which for a while was a classified term. But in 1934, the army committed to moving radar forward to become a formal program.

Ray Chase (11:17):
The army also had a radar program and in 1934, the Signal Corps Chief proposed that a radio echo system should be developed and the army continued work on it. And because of the problems of developing any power level at the super high frequencies, they also investigated the use of infrared detection to detect the heat of an approaching aircraft. This was all aimed at trying to find a way of directing searchlights to be able to illuminate an aircraft target at night.

Speaker 6 (12:11):
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Speaker 2 (12:57):
After researching and developing radar for years, the army began establishing its first radar program. The SCR-268 under Colonel Roger Colton at Fort Monmouth in 1936.

Ray Chase (13:10):
He built a prototype of this equipment and scheduled a test of it at Fort Monroe. Now, keep in mind that this first radar's purpose was to provide guidance for searchlights. In other words, the radar would be the initial detector of the attacking aircraft and would then provide information so the searchlight could locate them in the sky and shine a light on them.

Speaker 2 (13:47):
This early radar was groundbreaking, but it had its limitations. While using a searchlight could target an aircraft upon detection, it didn't give a lot of time for pilots to respond. Aviation pioneer, Army and later Air Force general, Hap Arnold recognized this limitation. He then justified why the next leap in radar technology needed to be developed.

Ray Chase (14:08):
General Hap Arnold, who was responsible for a pursuit type aircraft, and his comment was well, that's a wonderful system, but I need more warning. If you can give me a give me detection of them at a greater range, I can then get my pursuit aircraft up after them. So this released a major amount of funding and the army shifted to developing a long range, radar quality SCR 270 or 271 models, which went into production. And the SCR 268 was worked on as a searchlight directing radar, which later on, turned out to be useful for direct gun fire control and eliminated the need for having a searchlight.

Speaker 2 (15:06):
The SCR 270 radar was ready to use. It was sent to the O'Connor Radar Site in Hawaii, specifically to track Japanese planes. This radar would come to play an important and unfortunate role in the World War that would come to the United States through the attack of Pearl Harbor.

Mike Simons (15:23):
So the Army signal Corps had developed a relatively mobile tracking radar called the SCR 270 and those were deployed in the Hawaiian islands in 1941. The idea being that the Hawaiian islands would have been susceptible to attack from the Japanese Navy and those radar antennas were deployed in various parts of the island.

Speaker 2 (15:51):
But radar technology was relatively new and this created one major problem.

Mike Simons (15:55):
Now, one of the things about those early radars is there weren't very many people who knew how to operate radar. There was also in that point in America, even very few people that understood electricity and the concepts of electronics. So one of the keys to being able to operate those radars effectively and efficiently was practice, you had to practice on them. The interface between the operator and the radar, wasn't as intuitive as you see on modern radars where there's a sweep, and it makes a beep on the screen when they come across a target. So the operators had to practice and they practiced as much and as often as they could. Now, the military had an idea of when an attack might occur on the islands. And the idea was if the Japanese were to attack unannounced, they were going to attack early in the morning. So the radars were operated from just before Dawn to about seven o'clock in the morning.

Mike Simons (16:57):
And at that point, the radars were turned off and the operators were picked up and taken back. But in the particular radar site at Opana Point, the operators wanted to get a little more practice. So they kept their radar on a few minutes after seven, when at that point they picked up a large formation of aircraft coming in from the north, which is not the typical approach an aircraft in 1941 would have made to the Hawaiian islands from mainland US. However, the other part of the, of the equation here is even if the operators knew how to operate the radar and they knew what they saw, there was still the idea that the entire chain of command would have to understand how radar works.

Mike Simons (17:43):
So when they contacted the main base at Pearl Harbor, the lieutenant who was in charge had no conception of how radar worked and he sort of just, and to use a modern term, kind of blew it off, and told the guys, yeah, that's probably bombers coming in for Pearl Harbor. So the opportunity was lost to maybe get a slight jump on the Japanese. I think ultimately even had that lieutenant understood what information he was being given, there wouldn't have been enough time to make a significant difference.

Speaker 2 (18:37):
A war that America was trying to stay out of came to its doorstep on the morning of December 7th, 1941. The cost of the surprise attack on Pearl Harbor lasted only about 11 minutes, but the cost was devastating. 2,390 military and civilian lives were lost as well as the USS Oklahoma, USS Arizona, and most of the US airplanes lined up on the airfield. The success of the attack and resulting tragedy can't be pinned on a few individuals who lacked training on a new SCR 270 radar. Far from it. There was a lesson to be learned.

Mike Simons (19:13):
The lesson learned was that the radar was effective to locate the Japanese. And so radar became an even more important part of our defense network and what the US military did is they brought in experts from the UK who had been using radar for over two years at that point to help train the American operators on how the command and control from the radar set to the fighter could be done in a more effective way.

Speaker 2 (19:47):
Detecting enemy forces wasn't enough. There was a need for an established procedure of what to do when the radar echoed. The British had long been working on radar and were ahead of the US especially in command and control.

Mike Simons (20:01):
The British, unlike the Americans, had thought out the system completely from tracking incoming German bombers to how to notify the fighters, to how to distribute the fighters. And that system was in place before the Battle of Britain started, whereas we had the radar and it was an effective radar, but the whole chain of command was not as streamlined, as well thought out as what the British had perfected already. So even though they tracked the Japanese aircraft coming in, it really took that whole system of tracking communication all the way down to the aircraft for it to work effectively.

Speaker 2 (20:57):
The truth is new technology like early radar can be a game changer and provide important advantages. But its value comes down to the people behind it. Command and control, training and the decision making process of war fighters.

Speaker 2 (21:15):
In our next episode of the History of Crows, we go back across the Atlantic to learn about the first large scale use of radar in combat during the Battle of Britain. This podcast is brought to you by the Association of Old Crows. Thank you to our episode sponsor BAE Systems. Learn more at crows.org/podcast. Thanks for listening.

The Echo
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