Thread by @TrentTelenko

This thread is another visitation to the post VJ-Day Joint Chiefs of Staff historical squeegee, Japanese electronic warfare edition. 1/

Back in December 2019 I got and Air Force Historical Research Association microfilm reel with the FEAF's Air Technical Intelligence Group (ATIG) No. 153 Japanese Radar Countermeaures report in it. 2/

This is an immediate post-war report on the Japanese ECM decoys and jammers plus the radar intelligence supporting same.

I'll break my review of this up into several messages. 3/

First, Radar intelligence.

Confirmed:

- The Japanese learned much from captured in the Philippines SCR-270 and SCR-268 radars. (Std Narrative)

- The Japanese were given intelligence from the Germans as to all Allied radar frequencies in 1942. (Std Narrative) 4/

- The Japanese at Rabaul had Allied IFF equipment and frequencies cold by April 1943 (Mk II IFF) and by May 1943 had all IFF codes (Mk III) identified. (New)
5/

- The Japanese appear to have tortured Allied POWs and captured tech manuals on planes on all allied airborne radars used in/near Rabaul including those with 10CM radar sets.(New) 6/

- In April 1944 German intelligence on UK H2S radars arrived. (Std Narrative regards happening, not when)

- In August 1944 the Japanese captured an AN/APQ-13 3cm radar and PPI scope from a ditched China based B-29 in Amura Bay, Kyushu. (New) 7/

- USN & USMC Night fighters had poor light discipline approaching Japanese night bombers and the Japanese indeed had a tail warning radar. (New -- but I have some troubles with both reports) 8/

- The Japanese night bombers had 25 cm window at Okinawa. (New)

- The Japanese were reusing B-29 dropped "Rope" decoys over Okinawa. (New) 9/

- The Japanese had deep knowledge of all the radar, radio beacons & check points plus associated communication procedures for the B-29 campaign over Japan. (New, see also POW abuse above) 10/

- The Japanese had reconstructed four AN/APQ-13 three centimeter radar sets from various and sundry crashed B-29's by the end of WW2 and lost them in another B-29 raid (Std Narrative) 11/

- The Japanese Army had developed a complete suite of jammers for all of the B-29 equipment above set for deployment in Oct 1945, (not only New, but paradigm busting) 12/

Disappointments:

- No mention of captured British radar and radar documents with Singapore.
- No mention how the Japanese got USN 57cm and 25cm night fighter aerial radar frequencies. 12/

Now the JCS squeegee moment.

The Japanese Radar 'standard narrative' acknowledges that the Japanese captured PPI scopes from USAAF B-29's. 13/

Now we know the American Joint Chiefs of Staff had solid & reliable information the Japanese captured a B-29 PPI scope in August 1944. 14/

They also knew from February 1945 7th Fleet interrogation of a Chief Perry Officer from Admiral Kurita's cruiser HIJMS ATAGO that she had a PPI scope in October 1944. 15/

The FEAF spent much time interrogating Japanese military officials about whether captured Allied IFF sets were used with less data.

Why didn't the post-war US Military interrogations of the Japanese ask whether the Japanese put a captured B-29 PPI scope on the HIJMS ATAGO? /End

P.S.

The tweet thread threw up over posting these pages I reviewed from the Japanese countermeasures report with the rest. So here they are now.