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Fort Monmouth’s Mobile Radar System Detected the Pearl Harbor Japanese Attack – But Nobody Believed It

On December 7, 1941, two members of the U.S. Army Signal Corps stationed at Oahu, Hawai’i, were utilizing the newest electronic long-range detection system when they observed what appeared to be a “large flight of planes” heading toward Pearl Harbor early in the morning.  They immediately reported their findings, but were told to “forget it” and the warning went unheeded.  Moments later, planes of the Imperial Japanese Navy attacked the U.S. naval base at Pearl Harbor, inflicting devastating losses and touching off America’s involvement in World War II.

In December 1939, the U.S. military established an Aircraft Warning Service (AWS) using a new technology system to defend American territory.  It employed the SCR-270B, the first United States long-range search apparatus created at the Signal Corps laboratories at Fort Monmouth, in 1937.   By 1941, the system was still so new it didn’t even have a name yet, and was so secret it had been given a standard Signal Corps Radio (SCR) number, the same as every other radio or other communications device developed by the Signal Corps.  It would eventually become known as “radar,” standing for “Radio Detection and Ranging.” 

The AWS established six mobile radar detector sites on Oahu, including Opana Point, a location 532 feet above sea level with an unobstructed view of the Pacific Ocean.  The SCR-270 set comprised four trucks carrying the transmitter, modulator, water cooler, receiver, oscilloscope, operator, generator, and antenna.   The antenna generated an electrical pulse into the sky.  If anything interrupted the electrical beams, the radar’s oscilloscope reflected the object as an echo.  Some echoes appeared constantly, such as from the nearby hills and cliffs, but others were temporary, and those were the ones the operators were focused on. These signals showed and tracked planes intersecting the radar transmitter’s beams.

On December 7, 1941, the Opana Point site was manned by Private Joseph L. Lockard, 19, and Private George Elliot, 22. 

Joe Lockard was born on October 30, 1922, in Williamsport, Pa. He enlisted in the U.S. Army in August 1940, and was sent to Schofield Barracks, Hawai’i, for basic training in December, 1940. After completing basic training and basic radio operator training, he was assigned to the Army Signal Corps and was then trained as a radar operator.  Opana Point was his first assignment as a radar operator.

George Elliot, a native of Chicago, joined the Army in 1940 and first attached to the Army Air Corps before transferring to the Signal Corps early warning system. He was an apprentice radio operator on the day of the Japanese surprise attack. 

Just after 7:00 a.m., Mr. Elliott saw ”something completely out of the ordinary” on the screen: a huge blip, due north, 137 miles out.  Their shift was to end at 7:00 a.m., but as the truck to take them to breakfast was late, the pair continued to practice with the radar equipment.  They kept tracking, and the blip grew so large that Mr. Lockard figured the radar set was broken.  The more experienced Lockard took over the dial controls, and Elliott went to the plotting board. They calculated a large flight of planes off Kahuku Point, approaching at three miles a minute. 

Lockard and Elliott notified the information center at Fort Shafter.  On duty was switchboard operator Pvt. Joseph McDonald and new Air Corps Lt. Kermit Tyler.  Lockard told Tyler that the radar blips suggested “an unusually large flight – in fact, the largest I have ever seen on the equipment.”

Tyler replied, in effect, “Forget it.” It was 7:20 a.m.  Tyler assumed the planes were B-17s from the West Coast, bombers from Hickam Field near Honolulu, or Navy patrol planes.

Lockard and Elliott continued to follow the temporary echo until 7:39 a.m., when it was lost in the permanent echo created by the surrounding mountains. A short time later, the truck came to take them to breakfast.  About 10 minutes later, the first bombs were falling on Pearl Harbor.

Lockard and Elliott could see the black, oily smoke down in the harbor on their way to camp; back at camp, they knew immediately what they’d seen on radar.

Joe Lockard, 19 years old at the time of the attack on Pearl Harbor, had been in the Army a little more than a year.  In the aftermath of the attack, he was given almost complete credit for spotting and reporting the approaching Japanese aircraft.  He was promoted and sent to Officer Candidate School and awarded the Distinguished Service Medal.  On July 12, 1942, he was commissioned a second lieutenant in the Signal Corps, one day ahead of the rest of his class of 855 new Signal Corps officers at Fort Monmouth.  Lockard left the Army in December 1945 and held a variety of jobs.  He started first as a trackman for Pennsylvania Railroad; when he left, he was a maintenance supervisor. He worked for Sylvania Electric and then AMP Incorporated, from which he retired in 1986.  He was an inventor for AMP and holds some 40 patents for switches and connectors. He has the original patent, for instance, on the switch inside your garage-door opener.

George Elliott was transferred to Fort Monmouth in 1942, like Lockard, to attend Officers’ Candidates School but he “just missed” getting a commission. But Elliott did meet the former Margaret Wright of North Long Branch, and they were married. George served in the Army stateside at a number of posts (other reports say he spent the rest of the war at Fort Monmouth) until his discharge as a sergeant in 1945; he was relegated to being a footnote to the Opana Point event until joint congressional hearings on the attack in 1946.  After lobbying from senators, the Army gave Elliott the Legion of Merit for his actions on that day, but he refused to accept the medal, saying he should not be given a lesser medal than Lockard.  Years later, he said that he refused the medal because they were just doing their jobs, just looking at screens, and that it might be different if lives had been saved. After the war, he decided to return to Long Branch, where he lived, and worked for New Jersey Bell Telephone for 33 years.

The timing of the detection of the incoming Japanese attack is such that had the planes departed 30 minutes earlier, the outcome might have been a little different.  The radar sites in Hawaii operated for only three hours, from 4:00 – 7:00 a.m., and in the peacetime Army in Hawaii, after 7 a.m. the sites were unmanned.   Had the planes been detected even just a brief time earlier, the army and navy might have been able to put up a more effective defense.

The actions of the radar operators have been depicted in the 1970 movie “Tora, Tora, Tora,” as well as on TV documentaries and in history books.

The Opana Radar Site is a National Historic Landmark that commemorates the first operational use of radar by the United States in wartime. It is located off the Kamehameha Highway just inland from the north shore of Oahu, Hawai’i, south of Kawela Bay.  Situated within a modern Navy telecommunications station, it is not open to the public.  Since the 1941 radar was a mobile unit, there is no physical evidence of the original radar equipment at the site. There is a commemorative plaque on the grounds of the Turtle Bay Resort at the foot of Opana Hill.


Pearl Harbor – PVT Joseph Lockard.  Notable Signaleers.   Office of the Chief of Signal, U.S. Army Signal School.  Available:

George Elliott, 85; Warning on Pearl Harbor Went Unheeded.  (2003).  The Los Angeles Times, December 26, 2003, Part A, P. 2. Available:

George Elliott Jr., radar operator, dead at 85.  (2003).  Associated Press, in the Honolulu Advertiser, December 24, 2003.  Available:

Klaus, Mary.  (2012).  Remembering: Joseph Lockard, was in the Army during Pearl Harbor attack.  The Patriot-News, December 7, 2012, updated January 5, 2019.  Available:

Price, Ed. (2003). George E. Elliott, Jr., Army radar operator who warned in vain of Pearl Harbor attack. Asbury Park Press, December 22, 2003, P. 15.

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