Why did Japan not use RADAR?

I can see you!


1 Like

They did


To preempt the answer Indy will probably give, the Japanese did have RADAR.

In general, their models just weren’t all that good, even when they worked.

Meanwhile, the Americans (once they started trusting it) integrated RADAR into their operations everywhere they could. And their RADAR was pretty damn good and reliable.


It’s not that their models weren’t as good for no reason, the Imperial Japsnese Navy did some early experiments with Radar. Radar transmissions can be detected by an enemy’s radio receiver at twice the distance that you, the transmitter, can detect the enemy. Therefore it was thought to be useless as it gave away a ship a advantage of surprise. The IJN placed a primary emphasis on nightfighting, stealth and surprise.

This is a very ‘ship to ship’ view of Radar, but Japanese thinking was not unreasonable.


Well the US and British models were just a lot better thanks to the invention of the microwave. With the microwave the radar could be smaller and have the same range (/ power) or the just same size but with higher frequencies (/ is also more powerful). If your radar is more powerful, you can detect ships further away and thus give you an edge in the waters. Or you can have a smaller wave length of your radar and have a higher spatial resolution and can thus detect smaller objects. If you have higher frequencies, you can also run into the strategic advantage of you been able to detect the enemy but your enemy not being able to detect you.

And I have read (somewhere but I don’t know where anymore) that the Japanese electronics (i.e. transmitters, receivers, and computers) were not of the same quality as their American or British counterparts given the same specs.


The Japanese use of radar was just mentioned in Indys last episode about the Solomons, and their use seemed pretty intelligent to me.


The Japanese experimented early witn radar, but found it could be detected by the eneny at twice the range at which it was usesble in combat. They initially concluded it was useless and absndoned ut for a while.

The British likewise were wary of radar at sea, only using it when necessary to maintain surprise.

Eventually the benefits of warning outweighed the risk of detection but tgat didn’t set in until 1943.


Valid points about the inferior quality of the technology - I also read one more contributing factor. Supposedly (and I am not sure about how much credence to give this claim; I’ve only seen it once a long time ago and I forgot the source) the Japanese military didn’t consider sitting in front of a radar screen an “honorable” contribution to the war effort. It was not directly killing the enemy. Something about the Samurai code, etc. I don’t see how the Samurai code would have much bearing at that day and age, but take it for what it’s worth.


In my research on my local Signal Corps training camp, I found that the US Army had pretty steep requirements for radar training. They recruited people with a radio background (professional or amateur) or electronics background, which wasn’t common circa 1940. Prospective recruits had to pass a course in radio before being trained in radar itself. Radar maintenance was yet another training course depend on passing the first two courses. The failure rate was really high.

I assume the US Navy had comparable standards for radar students.

I suspect the Japanese simply had a much smaller pool (total and per capita) of potential radar instructors and students to draw from. Also less industrial capability of manufacturing radar sets and replacement parts.

Radar maintenance in the South Pacific was surely very difficult because of the climate. Logistically too, especially for the Japanese.


Good points lots of private planes, radio and early TV sets makes for lots of people with basic knowledge. And learning these skills takes time. Not to mention the ability to distribute spare pats to places in the middle of nowhere. Like Kiribati (oops spoiler alert :rotating_light:. Nothing to see there.

1 Like

The USN initially looked askance at surface radar, but quickly after WWII began, they started putting it on ships in hopes of being able to fight the Japanese at night. This took about a year to train operators and get captains to believe it worked. At the same time, they embraced radar to detect aircraft, having ample examples - from the Brits, for instance.

The Japanese, on the other hand, had gone to great lengths to come up with an optical solution that allowed them to dominate night-actions all through the Guadalcanal campaign.

The Japanese, having a solution that worked, were unwilling to change, refusing to believe their superior techniques from early in the war weren’t superior any more.

Japanese development in radar was hampered by the rivalry of the IJA and IJN, which didn’t pool research and manufacturing techniques for basically the entire war. (The IJA actually deployed its own shipborne radar - for its own transports.)

Since the IJA and IJN were both the source of radar research funding, there was much duplication. Even then, high-echelon commanders simply didn’t believe radar was of any value.

PS - My dad was a radioman on a destroyer in WWII (the “Newman K. Perry”). Radiomen were sort of a level below radarmen, but both counted as ‘specialists’.


This makes perfect sense-good stuff!

1 Like