RADAR and Electronics

[oldpop2000]

I decided to begin a game oriented RADAR and Electronics thread. I have placed the technology from my completed 1956 game as Germany to start. Please feel free to include anything missing. We can go any direction you wish including learning the basics of RADAR, IFF etc. I have sites to provide that basic information and my own experience as a long range radar tech for the USAF and my 30 years working avionics for Naval aircraft including airborne search, fire control, IFF/SIF etc. 

I want to really focus on the uses of the technology in the game but historical questions can be interesting and fun. I have many books on the WW2 RADAR. The extraction below is the first know radar and the British did not invent it. Sorry mates. 

Christian Hülsmeyer

In 1904, Christian Hülsmeyer gave public demonstrations in Germany and the Netherlands of the use of radio echoes to detect ships so that collisions could be avoided. His device consisted of a simple spark gap used to generate a signal that was aimed using a dipole antenna with a cylindrical parabolic reflector. When a signal reflected from a ship was picked up by a similar antenna attached to the separate coherer receiver, a bell sounded. During bad weather or fog, the device would be periodically spun to check for nearby ships. The apparatus detected the presence of ships up to 3 kilometres (1.6 nmi), and Hülsmeyer planned to extend its capability to 10 kilometres (5.4 nmi). It did not provide range (distance) information, only warning of a nearby object. He patented the device, called the telemobiloscope, but due to lack of interest by the naval authorities the invention was not put into production. Hülsmeyer also received a patent amendment for estimating the range to the ship. Using a vertical scan of the horizon with the telemobiloscope mounted on a tower, the operator would find the angle at which the return was the most intense and deduce, by simple triangulation, the approximate distance. This is in contrast to the later development of pulsed radar, which determines distance via two-way transit time of the pulse.

Early surface search radar - Enables surface search radar (Search radar 1)

Improved surface search radar - Improves surface search radar (Search radar 2)

Early air search radar - Enables air search radar

Airborne radar - Enables airborne radar

Radar assisted gunnery - Increases gunnery accuracy with radar (FC radar 1)

Cavity magnetron - Increases radar range (Search radar 3)

Slow fade display - Increases radar detection chance

Improved air search radar - Improves air search radar

VHF Radio in aircraft - Increases CAP effectiveness

Early blind fire capability - Enables blind fire (FC radar 2)

Shipborne HF/DF - Improves intelligence and ASW capability

Improved blind fire capability - Improves blind fire accuracy (FC radar 3)

Proximity fuzes - Increases 5 and 6 in AA effectiveness

Anti missile jamming system - Reduces hit chance of missiles and guided bombs

[oldpop2000]

I highlighted two technologies. Here is a video about the cavity magnetron - www.youtube.com/watch?reload=9&v=bUsS5KUMLvw

I have worked on them and can explain it in more detail.

Here is a video simulation of the use of HF/DF sometimes called Huff Duff - www.youtube.com/embed/eYGvAm8MMvQ

One thing that surprises me is the absence of ECM or ECCM in the game research. They have anti-missile but ECM and ECCM is vital. Maybe some of you researched it and got it. It would be nice to know otherwise the team needs to include that research. I also do not see Zed Baker or a homing beacon development for getting carrier aircraft back to the ship, but again maybe it is just included in the development of the aircraft.

[orlunu]

RADAR - RAdio Detection And Ranging. Mr Hülsmeyer's original device could not do the latter, and his patent for an improved device with full RADAR capability was filed in... Britain. We're keeping that one.

Anway, as for ECM, what are we thinking for implementation? As far as I'm aware, the progression was essentially static jamming in the early years, spoofing developed in early WW2, anti-radiation missiles right at the end of WW2.
Static jamming would only really hurt enemy communications, so I find it difficult to think how this would be represented in game. Cause more misunderstood signals for the enemy?
Early spoofing was, as far as I'm aware, essentially restricted to interfering with air search and airborne radar. Does anyone know of game-period apparatus for spoofing surface-to-surface gunnery radar effectively?

ECCM, of course, only really makes sense to talk about in a context of known ECM...

[oldpop2000]

Jul 5, 2020 8:10:25 GMT -6 orlunu said:

RADAR - RAdio Detection And Ranging. Mr Hülsmeyer's original device could not do the latter, and his patent for an improved device with full RADAR capability was filed in... Britain. We're keeping that one.

Anway, as for ECM, what are we thinking for implementation? As far as I'm aware, the progression was essentially static jamming in the early years, spoofing developed in early WW2, anti-radiation missiles right at the end of WW2.
Static jamming would only really hurt enemy communications, so I find it difficult to think how this would be represented in game. Cause more misunderstood signals for the enemy?
Early spoofing was, as far as I'm aware, essentially restricted to interfering with air search and airborne radar. Does anyone know of game-period apparatus for spoofing surface-to-surface gunnery radar effectively?

ECCM, of course, only really makes sense to talk about in a context of known ECM...

Well actually, Hulsmeyer continued development, and did develop ranging information by aiming the beam at a certain angle, knowing that the height of the antenna was proportional to the distance the device could see, and simple calculations provided an accurate range. Let's give the man his due. The CRT was developed by another German, Karl Ferdinand Braun in 1897 and in 1907 Boris Rosing used a CRT in a receiver for TV. So, by 1934 when Watson-Watt and his team began their work on a simple RDF all the necessary technology was available. His biggest contribution was the development of a complete air defense system using radar, IFF, and integration with the RAF. 

As to ECM, the British developed a system to interfere with the German Lorenz system for blind bombing, also the use of chaff. WW2 saw the development of electronic countermeasures extensively. 

If radar had been developed earlier in the age, someone would have followed up with ECM. The real issue was that in the early 20th century, there was no real need to search, acquire and track aircraft until about 1917 when the Gotha's and Zeppelin's began to hit England, but there were other ways of detecting these slow moving aircraft. One technological invention is followed by another to impede or slow down the other invention. History show us. The British Chain Home was in service by 1939, and the German's did not suspect its importance until after the BOB but very quickly they developed a method of reducing it effectiveness.


www.radarworld.org/huelsmeyer.html

[oldpop2000]

1. By 1900 The physics of electromagnetic radiation had been discovered and tested.

2. 1897, the Cathode Ray oscilloscope was developed by Braun

3. 1904, the vacuum tube was developed by Fleming

4. 1904 Hulsmeyer demonstrates a collision avoidance system predecessor to the radar. Later, range was determined using the system.

5. 1921, the cavity magnetron was developed.

6. March 1924, the superheterodyne receiver was built and tested. 

If we examine the above, we can see that all the required technology was available by at least 1925. 

Personally, I believe that the radar could have been developed if the militaries of the world had felt the need and had the funds to research the technology. Keep in mind, that by 1918 all the nations had decided that the last war was the war to end all wars and that the airplane just was not that vital. But we know that the zeppelins and Gotha's did arouse some thoughts. Most nations were researching the use of sound and infrared detection systems which proved unusable until later in the century.

Radar, with funds and interest by the military could be available in a primitive detection system which could provide range and azimuth could be available by as late as 1925 easily. This has been a subject of much controversy in historical studies for years.


www.radartutorial.eu/04.history/hi04.en.html

A couple of more suggestions: change the name of the research to electronic technology. This would include HF/UHF radio, homing beams, bomb release radio beams, radar, aircraft radar, after radar could be ECM, Chaff etc. This could be a varied technology. It could start in 1900, 1905, 1910 etc. 

[oldpop2000]

On 25 February 1935 the Luftwaffe's existence was announced. In 1935 Watson-Watt was asked to comment on reports of a German death ray. He and his assistant quickly said it wasn't possible but that radio signals were possible to locate aircraft at long distances. February 1935 this was demonstrated. Do you think these two events were just coincidental? Trust me, they weren't. Again, the need was finally apparent to all, and the funding became available. By 1939, four years later, the simple chain home system was built and tested, ready for war. But consider how far along Chain Home high and low might have been, if they had begun in 1925. 

[oldpop2000]

Just some interesting links for information.

www.ibiblio.org/hyperwar/USN/ref/Radar-OSRD/index.html
www.ibiblio.org/hyperwar/USN/ref/RADONE/index.html#II

[oldpop2000]

Another very valuable electronic tool is the radar altimeter. It's ok to use the Aneroid barometer which gives you the altitude above mean sea level, but that is not sufficient for bombing where you need the altitude above the actual ground. Flying over ground that is not mapped adequately very dangerous especially for low level attacks. The first proposals were in the 1920's by Heinrich Lowy for using pulsed HF waves to perform the task. The first real attempt was by RCA and NRL. The first deployable equipment was the SCR-518. I suggest that this piece of electronic technology be added to the list and research started no later than 1925. 

Eventually this tool coupled with the forward looking radar, began the terrain-following systems now deployed on all aircraft.