Author Topic: Radar Realism II  (Read 490 times)

Offline dtango

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Radar Realism II
« on: July 26, 2001, 01:24:00 AM »
Thought it was time to start another thread on this since the other one started by Airscrew was getting a little long.  My main purpose is to share some observations on WW2 radar to help clarify a little on WW2 radar realism and to gently challenge some assumptions by those who claim to want more "realism" for radar usage in AH.

First, An Observation / Opinion
Let me diverge a little first.  I think HTC have their reasons for implementing the current bar radar and dot radar as it is.  I don't claim to know what those reasons are.  My observations on the consesquences of the current radar are as I've stated in the other thread:

[list=1]
  • It helps people find where fights are and lets them get into the action quicker.
  • It forces strikes, missions, field captures etc to be well planned and executed.
  • [/list=a]

    Whether intentional or not, I think HTC has struck a good balance for those wanting to get into the action without wasting too much time and those who really want well planned missions.  My OPINION is that HTC's implementation of the dar is mainly to reward certain types of behavior vs. trying to simulate ultimate radar realism.  Okay, enough on that tangent.

    SOME OBSERVATIONS ON RADAR IN WW2 AIR COMBAT
    ================================================

Radar usage in WW2 air combat was quite extensive and was readily available for various combatants early in WW2.  Not only that but directing WW2 air battles was quite sophisticated.

Students of the Battle of Britain know that a very crucial element of the British integrated air defense system that gave it the ability to fight against superior LW numbers were the Chain Home (CH) and Chain Home Low (CHL) radars.  CHL stations were set up to detect aircraft below 3000 ft.[1]  CH & CHL stations began showing up sometime in 1935-36.  The Brits had several years to perfect their usage in directing the air battle and this proved to be true by 1940.

Information provided by the radar was pretty detailed.  “CH stations could detect aircraft up to 100 miles away, and could give the bearing and an approximate indication of the height and number [of aircraft] of an approaching formation.”[1]

Knowing enemy formation information wasn’t enough to achieve accuracy in control.  “To achieve accuracy in control had been a problem, but during 1939 ‘Pipsqueak’ had provided the answer.  One fighter in each section of three switched his R/T on to this device, which produced periodic signals picked up by D/F (direction-finding) ground stations.  Crossbearings from these fixed the fighters’ position, which could be continuously plotted.  Armed with this information, and with knowledge of the enemy’s course derived from the radar and observer plots, a controller on the ground could give his pilots over the R/T a ‘vector’, or compass bearing which would…bring them to within sight of the enemy.  This ‘controlled interception’…was to be the basis of Fighter Command’s operations in the forthcoming Battle.” [1]

The point is CH & CHL usage along with ‘Pipsqueak’ was pretty sophisticated by 1940 and played a vital role in the direction of the air battle during BoB.

The result was incredibly effective.  “The tall radar towers, long since correctly identified, were clearly proving more effective than the German High Command had reckoned…The last month’s fighting had disquietingly revealed how, time after time, the weight and directions of Luftwaffe attacks had been anticipated so early by the RAF that the fighter squadrons were there, awaiting them like tipped-off gangland rivals.” [1]

Radar usage for directing air defense was not the solely a Brits only technology.  The Luftwaffe also established the effective use of radar in directing air battles early on in the war specifically to counter RAF Bomber Command’s night bombing campaign.  “German defenses were transformed by the addition of radar in the autumn of that year [1940].  The large Wurzburg radar units were set up, one in each of a series of grid ‘boxes’ drawn on a map, roughly 20 miles across.  Within each box a night-fighter could be directed to intercept any bomber picked up on the screen.  A central control room kept each fighter within its sector, circling round, waiting for its prey.” [2]

By 1943 The German air defense was quite formidable.  It was this same command and control system that caused so much grief for the 8th Air Force with the lack of long range escorts.
 
IFF technology was available early in WW2.
Both the Brit and LW examples of usage of radar depended on being able to identify friendly craft- e.g. the Brits “Pipsqueak”.  “Indentfication friend or foe (IFF) was a proven technology.  The British had developed IFF and used it effectively in the Battle of Britain.  RAF aircraft carried a transponder that was activated by British radar signals and sent back a pulse that showed up in radar stations as a green light.  All other radar returns triggered red lights.”[3]  These series of lights helped plotters with plotting friendly and enemy aircraft.

Interestingly enough the Brits had offered the technology to the US as early as August 1940 “but the Signal Corps was too proud to take the gifts from the foreigners”[3].  The Signal Corps’ SCR-270 mobile radar systems that it was so proud of was useless without IFF as evidenced by SCR-270 located at Opana Point, Hawaii on December 7th, 1941 that picked up the Japanese raid on Pearl Harbor that was surmised to be B17’s returning.[3]

Electronic Warfare Was Definitely a Part of WW2 Air Combat.
What may be somewhat surprising of folks is some of the Electronic Warfare activity during WW2 in air combat.

There are examples of ECM that the US had but it was fairly crude at the time.[3]  The RAF came up with a way and device to jam the German night-fighter airborne radar known as the Lichtenstein with a device called the SN2 with some success.[2]

Some other examples of Brit ECM is quite intereseting.  “On some nights British radio jammers succeeded in talking over the German controllers and directing fighters to the wrong town; on some occassions they played recordings of the Fuhrer’s speeches to apoplectic pilots who were forced to circle around in an aerial no-man’s-land.  But such a ruse was very hit-and-miss.”[2]

Chaff on the other hand was used quite extensively by the Brits and USAAF in 1943.  “To supplement it [ECM], there was “window” or “chaff”.  This consisted of strips of aluminum foil, like Christmas tree tinsel.  Bomber crews were given bales of the stuff and told to throw out a few strips at a time to create an electronic blizzard on enemy radar screens.  Not suprisingly, window got thrown out in handfuls, or by the armload.  During intense flak, entire bales would hurtle through bomber formations, glittering and sparkling as they came apart.”[3]

I’ve written a novel and will quit now.

References:
[1] The Battle of Britain, Richard Hough / Denis Richards
[2] Why the Allies Won, Richard Overy
[3] Winged Victory, Geoffrey Perret

[ 07-26-2001: Message edited by: dtango ]
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Offline Pepe

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Radar Realism II
« Reply #1 on: July 26, 2001, 01:34:00 AM »
Dtango,

Nice post.

On the radar issue, still no dot radar inflight, no GPS available, except in night fighters for what inflight radar is concerned.

Was CHL able to detect planes under 150 ft?

Cheers,

Pepe

Offline Karnak

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Radar Realism II
« Reply #2 on: July 26, 2001, 02:11:00 AM »
dtango,

Nice effort, but I don't think you can change the minds of those who want WWI combat with WWII aircraft.  They're pretty fixated on what they consider realistic.

Yes, calling what they want WWI combat is just what I consider it, and thus just another useless opinion.
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Offline Kirin

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Radar Realism II
« Reply #3 on: July 26, 2001, 04:57:00 AM »
OTH, I don't think you can change the minds of those who want StarWars(TM) combat with WWII aircraft. They're pretty fixated on what they consider realistic.

Hehe, couldn't resist - sorry... Sitting at the university - not in the mood to stick my head into the books - booored...  :D
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Offline xHaMmeRx

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Radar Realism II
« Reply #4 on: July 26, 2001, 09:51:00 AM »
Maybe what is needed is a "dead" zone around your plane where other planes don't show up on dar.  A logical radius would be con range.  Once you can visually "identify" (via an icon) a plane, it is within your immediate area of concern and no longer subject to updates from ground control.  With this system, you can no longer use dot dar to fight the fight, only to get within con range of it.  You can still use it to figure out if that dot in the distance is friend or foe, but not to see if there is a bandit on your six.

What it boils down to is that there was pretty good information available to pilots on factors that affected them.  Things such as number of planes, altitude, direction of flight, and friend or foe were available to them from ground control.  All of these were designed to get them to the fight.  Once in the fight, there was no system for reporting information on the immediate situation such as a plane on your six.  The problem is translating this situation into arena type play.

During BoB and other WW2 situations dtango is referring to, the key to success of ground control was that a pilot or squadron received information from their controller that was relevent to them and their location or assigned sector.  Other controllers provided other pilots/squadrons information that was relevant to their location.  A pilot didn't get information that didn't pertain to him.

Some people have advocated radio type messages over the text buffer to simulate ground control, warning of attacks on bases, etc etc.  The difficulty in applying this to the main arena lies in the fact that it covers such a large area with so many small battles happening simultaneously that the text buffer would quickly become full of constant updates.  Picking out an update that was relevant to your location would be difficult at best due to the volume of message traffic that would have to be generated.  There would be too much irrelevant information for that system to work.  While I'm not a programmer, it would seem a nightmare to "localize" reports to some radius of each individual plane.

I agree with dtango that the current dot-dar seems a pretty good compromise for providing information to find a fight.  In fact, as he pointed out, it lacks altitude information which was available.  On the other hand, using the same dot-dar to make sure your six is clear is admittedly unrealistic.  This is where the "dead zone" would work.

Sorry for the book!

HaMmeR

Offline xHaMmeRx

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Radar Realism II
« Reply #5 on: July 26, 2001, 10:06:00 AM »
Quote
Originally posted by Pepe:
...Was CHL able to detect planes under 150 ft?

Are there any examples of successful daylight deep penetration NOE raids over enemy territory?  I know of a couple of night-time raids.  The day-time raids I am familiar with were carried out by the LW against London using Fw 190s.  These LW raids usually were able to drop, but were often interecepted on the way out. My source for this is memory of reading the "Luftwaffe War Diaries"...I'm at work and don't have it here. Anyway, considering you can get fairly close to London before going "feet dry", this would seem to indicate that low-level flying might get you an initial suprise, but it would not be effective for deep penetration.  Anyway, was wondering if anyone could provide information on successful NOE deep raids during daylight?

HaMmeR

Offline AN

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« Reply #6 on: July 26, 2001, 11:07:00 AM »
xHaMmeRx:
------------------------------------------
Maybe what is needed is a "dead" zone around your plane where other planes don't show up on dar.  A logical radius would be con range.  Once you can visually "identify" (via an icon) a plane, it is within your immediate area of concern and no longer subject to updates from ground control.  With this system, you can no longer use dot dar to fight the fight, only to get within con range of it.  You can still use it to figure out if that dot in the distance is friend or foe, but not to see if there is a bandit on your six.
-------------------------------------------

Great idea!  

anRky

Offline popeye

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Radar Realism II
« Reply #7 on: July 26, 2001, 12:34:00 PM »
Just introduce a delay in updating inflight dot dar.  Update dots every 10 (?) seconds.

This would allow you to find a fight, and see the radar contacts general course, but not provide too much SA.

In the tower, keep dot dar just as it is now, with continuous updates.

(To add Strat into the formula, tie the dot update rate to the condition of HQ.)
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Offline dtango

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Radar Realism II
« Reply #8 on: July 26, 2001, 02:00:00 PM »
I don't have too many illusions about converting the masses to see the error of their ways  :).  Seriously though, just wanted to point out that the use of radar in WW2 is more sophisticated than some assume.

On the effectiveness of CHL on very low flying aircraft, I don't know what the "minimum" limits were.  Bear in mind that radar as in all things in the real world is not as simplistic as we tend to make it out to be.  There isn't a magic 500 ft limit that makes any plane invisible to radar.  Flying "below the radar" is a complex proposition.  I believe that the principle is that flying closer to the ground reduces the probability of detection because the returns from ground clutter.

On successful low-level raids I was browsing for some references earlier but didn't come across any.  I thought I had read some reference about Epro 210 (a specialized LW Me 110 Sq) making low-level penetrations during BoB but didn't know what conditions that was under (e.g. through a radar gap after a CH or CHL stations was taken down).
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Offline dtango

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Radar Realism II
« Reply #9 on: July 26, 2001, 11:09:00 PM »
xHammerx- I meant to comment and say that I think your analysis on the "problems" with making AH radar etc. more closely mock WW2 ground controller is right on.  I think you are right on also about being vectored to within contact and then relying on visual SA after that.  I like your idea of a radar dead zone around your fighter.

Some more ramblings on radar in WW2 for anyone that cares and may find interesting:

[list=1]
  • Airborne radar played a key role in the Battle of the Atlantic in hunting U-Boats down.  In 1943 airborne radar was used very effectively to hunt down U-Boats.  The thing that amazed me is that the lookdown capability of the radar was good enough to spot even a periscope out of the water.  Apparently the radar was effective to up to 1 mile of the contact.  This worked well during the day time.  At night it proved to be problem until someone came up with an ingenious solution to mount huge floodlights that were slaved to the direction of the contact and would automatically turn at the 1 mile limit to substitute for the radar.  The electronic war definitely see-sawed back and forth once airborne radar to hunt U-boats came into use.
  • The Russian AF by 1943 was becoming a contender vs. the LW.  A part of this was the employment of radar in air battle management.  At the battle of Kursk the Russians proved they had operationalized the improvements to the dismay of the Germans.
  • Radar was tried as a tool to improve aerial bombing.  Radar directed bombing was one of the areas that remained fairly crude during WW2 and was met with limited success.
  • Radar was also used by the Allied bomber forces to navigate and guide bombers so that they could accurately get to the target at night or when there was heavy cloud cover.
  • [/list=a]

    [ 07-27-2001: Message edited by: dtango ]
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"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)

Offline dtango

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Radar Realism II
« Reply #10 on: July 27, 2001, 08:01:00 PM »
Pepe- found a little information regarding your CHL question.

The CHL radar could detect aircraft flying at 500 feet at ranges of up to 30 miles.

Reference: http://schoolsite.edex.net.uk/468/radar.htm
Tango / Tango412 412th FS Braunco Mustangs
"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)