In the book
Echoes of War: The Story of H2S Radar, there's some information about
H2D radar tested in 1944. H2D is (in the book) said to be a Pulsed Doppler version of H2S series.
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However WW2 magnetron could only give random coherent signal. It seems impossible for ww2 tech to achieve any kind of "all
coherent" which is a basic requirement for what we nowadays call "Pulse Doppler".
Some radar devices used Doppler effect in ww2 such as Fakir and Tastlaus (German), but these were not "Pulsed Doppler"/"Pulse Doppler".
Klystrons can produce coherent signals, and there are klystron versions of H2S radar according to the book. However, according to Merrill I. Skolnik, there was not any Pulse Doppler radar in ww2 - PD was a 1970s tech.
The author of the book
Bernard Lovell was one of the key persons in H2S project so these claims in his book should hardly be wrong.
So maybe the meanings of the "Pulse Doppler" are different? (1940s, 1970s, nowadays)
TNA documents
AVIA 7/2514 and
AIR 20/877 are about H2D trials so there may be more details but I'm not in the UK.
Below is my take on what you are seeing. Keep in mind I have very little knowledge of the H2S specifically, but this thread has piqued my curiosity, and I will endeavor to educate myself on the subject.
The book you quote was written in the late 1980's I think. By that time the term "Pulse Doppler radar" was in common use. Maybe it is a case of applying a later term to a technique that existed at an earlier time, but was not yet referenced using that same later term. I would say this technology being experimented with in WW II is very possible if there were, indeed, Klystron versions of the H2S.
From publications of the period it is pretty evident that the technology behind what we now call "Pulsed Doppler" was well enough understood before the end of the war to produce a system using that technique. I will go to my old standby, the MIT Radiation Laboratory Series, published in 1947. For those not familiar, this is a 28 volume set published immediately after WW II, documenting the state of knowledge, with regards to radar technologies, at the time of publication. In the spirit of the everlasting peace just won, things heavily classified just 18 months previously were freely published. Because, you know, we would never have a war again or anything..... And yes, at least 10 sets were delivered to the Soviet Embassy in Washington DC.
A search through these publications shows that the term "Pulse Doppler" is never used in the body of the text. However, the technique is defined without that specific name, and the name is indirectly referenced in a footnote.
The index (Volume 28) contains a reference (page 45) to "Doppler, pulsed,
20 20". This indicates the subject is covered in Volume 20, starting on page 20.
Volume 20 is "Electronic Time Measurements". Page 20, section 2.9, discusses "Pulse Systems - Externally-coherent Echo Interference". How to measure and detect moving targets on the ground, via Doppler detection of the radial velocity, is discussed in detail over the next few pages. While they do not talk about any specific hardware, from the text it is obvious that they had been doing a good bit of work in this area, using terms like "were able to detect vehicle motions of under 5 MPH" and similar. It also contains a footnote referencing another document, "Pulse Doppler with Reference to Ground Speed Indication", RL Group Report, March 30, 1944. Note the use of "Pulse Doppler" in that reference.
Volume 19 is "Waveforms" and goes into all the detail needed to do a PD radar, including the specifics of phase detection and storage.
Re Skolnik saying that there was no PD radar in WW II, and that it was a 1970's technology, can you be specific where this is said? I am pretty sure modern PD radars go at least back to the 1960's, if not the late 1950's. Most of the time I hear of the AN/DPN-53 (in the IM-99B missile) as the "first production PD airborne radar" and that goes back to the late 1950's. I have pictures from BOMARC testing in the early 1960's on my office wall. But I also know (well, have been told) that onesies and twosies PD systems predate the AN/DPN-53.
A thought. There are a couple of definitions for "Pulse Doppler". In more recent times it has generally defined a high or very high PRF radar with high range ambiguity and low Doppler ambiguity. Prior to that the definition did not include a description of the PRF rate. By a definition that includes that high or very high PRF (with high range ambiguity) caveat, it is probable that nothing we would call PD did exist in WW II, even if the basic technique was actually in use in a limited way.
T!