Thread by @TrentTelenko

This thread is going to be about explaining Radar & Photo Intelligence in the Pacific War

Some of what follows was in previous threads (link), but need further narrative to explain the context of GHQ SWPA Section 22 in the WW2 intelligence community.

https://twitter.com/TrentTelenko/status/1362812609192370178

There was a whole lot of strange in how the US Military did what we call ELINT type intelligence today, during WW2. There was no Washington DC or Pacific Theater equivalent of R.V. Jones Air Ministry "Scientific Intelligence'" or today's DIA doing the ELINT function.

Section 22 was utterly unique as an ELINT intelligence agency in the US Military in WW2.

Quite literally the only people in the USA who really *understood* Section 22 reports were the MIT Rad Lab guys in the liaison office that became...

https://twitter.com/TrentTelenko/status/1362812630889504777

...the "Joint Electronic Intelligence Agency" (JEIA), the "ORSD Division 15" Harvard Laboratory radar boffins plus similar USAAF people at Eglin Field in Florida.

The key thing to know about Radar intelligence in Nimitz's theater is that in the Joint Intelligence Center, Pacific Ocean Area (JICPOA). The Radar Intelligence function was handled by its photo intelligence section. This was an
en.wikipedia.org/wiki/Joint_Int…

...outgrowth of the invention of the radar planning device by the US Navy and radar experts from the MIT Radiation Laboratory.

A "Radar Planning Device" was a 3D model of the terrain with a spinning light and time lapse camera to create a black & white

https://twitter.com/TrentTelenko/status/1363129557843288071

...PPI type photo simulation of radar returns. It was a terrain model model and film camera that served the purpose of modern computer mission planning software used to plot warplanes courses through the radar coverage of an integrated air defense.

These are three quick links to documentation on the RPD.

RPD Patent
patentimages.storage.googleapis.com/pdfs/US2940072…

US Navy CIC magazine with RPD article
maritime.org/doc/cic/cic-45…

A May 1946 Coast Artillery branch magazine with a "How to do RPD photos w/o an RPD" article
sill-www.army.mil/ada-online/coa…

The Joint Intelligence Center Pacific Ocean Area -- like Naval intelligence in Washington D.C. -- had been pigeonholed Radar Intelligence or what is now known as "electronic intelligence" (ELINT) inside photo intelligence as an "other duty as assigned."

In the ETO/MTO, R.V. Jones'" Scientific intelligence" branch of the UK Air Ministry was so competent that the US Military simply used their product rather than reinvent the wheel.

Nor did the War Department's Military Intelligence Division bother with creating Radar intelligence until after it created a Pacific intelligence section in September 1944.

And it didn't add Ultra codebreaking to scientific intelligence until June 1945.

It was the need for 8th and 15th Air Force to use active radio countermeasures (RCM) versus German radar's while executing the Pointblank Directive that saw "Radar Intelligence" evolve as a separate intelligence specialty in the USAAF, unlike the US Navy.

I suspect there was also an element of organizational imperative to stand up a separate USAAF intelligence specialty, vice the rest of the War Department, as an element of the Air Force's future independence.

The "Section 22" radar hunters (AKA ELINT) in MacArthur's SWPA theater evolved out of the Central Bureau's low level signals intelligence (SIGINT) of IJAAF & IJNAF message traffic, plus the D/F and traffic analysis of higher level radio codes in the Buna and Rabaul campaigns.

The British referred to such lower level signals intelligence as "Y-Service."

The Central Bureau located all the radio equipped Japanese aircraft early warning ground observers around Rabaul and then spotted the arrival of...

...Japanese radar supplementing this air defense warning network from early 1943 to early 1944.

https://twitter.com/TrentTelenko/status/1362812639974354947

The precursor of Section 22 stood up in June 1943 as a RCM section of GHQ SWPA and the identity of "Section 22" happened in November 1943 when this RCM section was given
1) Its own "Ferret" Radar-hunting aircraft assets to control directly,

https://twitter.com/TrentTelenko/status/1363129530760630277

2) The mission to train Australian-American radar crews in anti-jamming tactics,
3) The additional mission of listening to Allied communications w/Australians when the General Akin could not get Signal/Staff Information and Monitoring (SIAM) platoons and companies,

4) The role of calibrating Allied radars, &
5) The mission of radio deception aimed at the Japanese military.

General Akin also got rid of Section 22's founder, Lt. Cmdr. Joel Henry Mace, RANVR.

Mace had stepped on more toes than the Central Bureau's. They stepped back.

https://twitter.com/TrentTelenko/status/1362812621829726208

In early 1944 Lt. Cmdr. Mace was sent on a long overseas liaison/business trip to the USA, the UK & the Mediterranean...

...without a return ticket.

It was not all downside for Mace.

He got to hang out with Commander Douglas Fairbanks and his US Navy Beachjumper radio and visual deception unit in Italy & Southern France.

historynet.com/douglas-fairba…

Returning to mission #3

SIAM units were the U.S. equivalent of General Montgomery's "J-Service" in North Africa that listened to his own message traffic so he would know what was going on during battles faster than then arthritic British Army radio communications could provide.

Giving Section 22 the ELINT and J-Service missions in the SWPA vastly simplified Gen. Akin's security clearance personnel problems since neither required ULTRA level security vetting like the Central Bureau required of it's Y-Service signals intercept personnel.

The US Navy in the Central Pacific did not perceive land based Japanese radar as a real threat until early 1944 and by then the ultimate priority of US Navy RCM was aimed at the German radio guided missile threat and the Normandy invasion.

This put the Navy in the Central Pacific a year behind compared to the capabilities of Section 22 in the summer of 1944, with the wrong intelligence structure to deal with ELINT compared to MacArthur's theater.

Then the US Navy and the Office of Scientific Research and Development (OSRD) invented the Radar Planning Device (RPD) that simplified location hidden radars by simplifying the siting the best radar coverage positions on the ground.

Top notch USN photo intelligence people could use the RPD and ELINT D/F cuts to steer photo intelligence missions to the most likely radar locations.

By January 1945 they were very good...and then Nimitz moved his theater HQ to Guam.

Jeffrey M. Moore's 2004 book "Spies for Nimitz: Joint Military Intelligence in the Pacific War" makes clear that photographic intelligence, Ultra decoding and document translation were the keystones of JICPOA intelligence support in the Central Pacific drive...

...drive and for reasons bureaucratic and technical I laid out above, radar intelligence became a sub-set of photo intelligence.

Also according to Moore, the Navy bureaucracy in Jan 1945 considered Hawaii a rear area with the departure of Nimtz's theater HQ, and it wanted

...to rotate long time rear area folks to combat billets. This absolutely scattered all of JICPOA's best photo interpreters to Nimitz's Advanced Intelligence Center in Guam, the various carrier group intelligence units, and a small photo processing facility at Ulithi anchorage.

This same bureaucratic action also had the effect of scrambling the remaining yeoman in JICPOA. The 80/20 model applies here. About 20% of the JICPOA yeoman did 80% of the distribution work because they knew the file system at JICPOA best because of having years of experience.

So, in Jan 1945 about 10% of the best male yeoman went to AIC, and the remaining 10% of the "Effective 20%" were scattered to the four-winds by the same bureaucratic action that hit the photo interpreters.

NB: In terms of both photo and Radar Intelligence, The US Navy lobotomized it's main intelligence arm -- JICPOA -- in the middle of moving it's theater HQ for the first time in the war, it had inexperienced 2nd raters doing photo interpretation at Hawaii, and

...inexperienced 2nd raters distributing what they produced, during its two biggest amphibious operations (Iwo Jima and Okinawa) in WW2!

That wasn't the only intelligence failure across theaters in the Pacific.

Coordinating radar intelligence flights at Okinawa simply didn't happen.

https://twitter.com/TrentTelenko/status/1363849093995401216

What all of this meant was that the American Joint Chiefs had a huge problem in the summer of 1945.

The relative intelligence success of Section 22 compared to their efforts -- in light of the coming Congressional Pearl Harbor hearings -- was a threat to their budgets.

They had to make Section 22 go away.

A systematic Post War Historical Defenestration of both Section 22 and the effectiveness of Imperial Japanese radar in WW2 was conducted.

https://twitter.com/TrentTelenko/status/1364239699422765058

So out the window all of that inconvenient military intelligence history went.

Now the end of thread kicker.

If the Joint Chiefs did this for Section 22...

...exactly where else did they apply the historical squeegee?

@threadreaderapp unroll