Funkmeßortung auf der Bismarck ?

[Trimmer]

Na gut MS -  - möchte nur in diesem Zusammenhang mal auf die Seite - www.atlantikwall.info/radar/marine/marine.htm - hinweisen.Gut aufgeführt auf welchem Schiff was war.

Trimmer-Achim

[Lutscha]

Mal zum Thema Radar/Radardetektor kopiert von Dave Saxton von Kbismarck: http://www.kbismarck.org/forum/viewtopic.php?f=1&t=764&start=75

"Vic,

The Germans did not know about the 50cm and 10cm radars at the time of the Bismarck. The 10cm radars were not known until the recovery of an almost intact H2S from a crashed bomber near Rotterdam in Feb 1943. The 10cm radar was given the codename Rotterdam and a committe known as the AGR(Arbeits Gemeinschaft Rotterdam) was set up to deal with it. The AGR records also tell us quite a bit about what the Germans knew and when they knew concerning Allied radar. In a time line presented at one of the AGR meeting it gives the chronology of Kriegsmarine passive detections of Allied radar from 1939 up to May 1944. The 50cm radar was first identified in March 1943.

Previous to the Bismarck operation the British had not possessed any sea surveilance radar capability at sea against the Germans.The Germans had logged detections of radar down to 1.3 meters wave length by the British mostly on land and on marine patrol bombers. The first logged detection of British shipborne radar was 1.4 meters in May 1941. Indeed the obvious use of radar came as a real surprize to Luetjens and had quite a psychological effect. The first 10cm sets had not reached operational status yet, and when that time came in late August it was deployed first on warships engaged in anti-U-boat duties. The first 10cm sets for large warships came in late 1941 and early 1942. These sets were general tactical sets. The first 10cm gunnery radars deployed in the Royal Navy came in mid 1944.

Gunnery radar at that time was mostly used for ranging and was used with visual bearing data. If the target was obsured such that it could not be seen well enough to obtain the exact bearing of the target then it could not be fired upon. Blind fire radar directed gunnery requires bearing accuracies of a fraction of a degree. Such accuracy isn't possible without lobe switching, no matter the wave length. The German radar originally had lobe switching but it had been decided to not use it on production sets in 1937, and at the time of the Bismarck a new more advanced method of lobing had not become fully deployed yet. The British gunnery radar did not have lobe switching at that time. Lobe switching versions began to be phased in during the course of 1942.

The German Seetakt radar in 1941 had a battleship to battleship range of 25km in the case of the Bismarck's sets (assuming sources are correct pertaining to the exact models installed), and the PG's more advanced models had 30km range to a battleship."

Wer nicht weiss, was lobe switching ist, schaut hier: http://en.wikipedia.org/wiki/Lobe_switching

[t-geronimo]

Und wer in Lutschas letztem Link auf das Diagramm klickt, bekommt dazu auch eine deutsche Erklärung, wenn auch kurz.
Letztere wiederum ist von dieser Seite:
http://www.radartutorial.eu/html/_start.de.html

[Lutscha]

Oh, hab ich gar nicht gesehen.

[t-geronimo]

Dafür sind wir ja eine Gemeinschaft. 

[Thoddy]

Mal ne bescheidene Frage
Die drei Seetakt version Calais Radargeräte alias FuMG 39(Gp) alias FuMO 23
sind an den Drehhauben der Basisgeräte befestigt gewesen.
Die Basisgeräte waren ja zweiachsig stabilisiert und gehörte die Drehahaube mit zum stabilisierten Teil und  waren demzufolge auch die Seetakts stabilisiert oder nicht?

[bernd]

Hallo Leute

hier mal eine Erklärung der Abkürzung FMG 39G(gP)

Gruß Bernd

[delcyros]

und auch von anderer Seite mal ein wenig input zum dt. Radar und deren Fähigkeiten. Auf eine Frage von mir bekam ich diese Antwort auf einem anderen board von einem Mitglied mit Namen "Wavelength", der uns seine Ansichten zu den komparativen Fähigkeiten der Feuerleitradare der USA, Englands und Deutschlands wie folgt mitteilte:

Originally Posted by delcyros View Post
I
I am also not sure what exactly the RADAR capabilities of SCHARNHORST and IOWA in late 1943 were. I understand that both ships had RADAR sets efficient enough to track an enemy BB-sized target and develop gunlaying solutions for the firecontroll using RADAR. I also understand that the US later build in a radarset to track gunsplashes which the DKM sets could not. I am not sure if this holds true for late 1943 as well. If so it would create a notable advantage for IOWA.
.

Understanding the comparative capabilities between the Iowa's WWII firecontrol radars and the late war German equipment may be better attained by first understanding the problems the Americans had with their earlier 40cm Mk3 firecontrol radars introduced in 1942.

The Mk3 was hampered by poor resolution for both range and also for bearing. Accuracy and resolution are not quite the same things. The accuracy for range and bearing of the Mk3 were actually very good. Resolution is however, the ability to resolve from among two or more closely grouped targets. The resolution for range is in most cases the function of the pulse duration. Radar pulses travel at a speed of 300 meters per microsecond (one/millionth second). Therefore a pulse of 1ms covers 300 meters distance. Since the leading edge of the pulse will have already rebounded off the target before the trailing edge of the pulse arrives, the range resolution will be ½ the pulse distance. A 1ms pulse gives a range resolution of 150 meters. A 2ms pulse gives a range resolution of 300 meters and so forth. The German GEMA radars were not strictly bound by these limitations because they utilized a different principle for processing range data. The range resolution of the Mk3 was 400 yards. It therefore had problems resolving shell splashes from the target itself and could not be used to correct the MPI (mean point of impact) of straddling salvoes or even if the salvo was a straddle or not.

The bearing resolution was also poor. This was because when lobe switching, which is necessary to attain a bearing fix accurate to fractions of a degree as required for gun laying, the Mk3's beam width became as wide as 15* . The bearing resolution is equal to the beam width. The beam width can be calculated by dividing the wave length by the effective size of the antenna. Therefore good bearing resolution comes from using shorter wavelengths, or larger antennas, or both.

When the Mk8 firecontrol radar began replacing the Mk3 during 1943 the Americans looked at Mk8 as something of a miracle device. Such advances often leads to the assumption that you have a capability nobody else has though. It operated on 10cm wave length and had a beam width of 2*. Its pulse duration was also decreased to about 0.4ms so its resolution for range was drastically improved from the Mk3's 400 yards, to about 70 yards. Another important improvement over Mk3 was the ability to lobe switch by manipulating the phase of the individual antenna elements or phased array techniques. The data was presented on a B-scope which was much like looking through rifle scope with the cross hairs on the target and splashes off line showing as such.

However, a type of presentation of bearing data similar to the B-scope and phased array techniques had already been in use on the German naval radars for years. The German sets were always quite capable of spotting the fall of shot. The German Seetakt radars were multirole radar sets, in that they were used for both surface, and air warning (The famous Freya air warning radars were actually a long wavelength version of Seetakt), as well as being very well suited for gunlaying. As mentioned above, they utilized a different principle for processing range data and could achieve excellent range resolution regardless of pulse duration, hence the ability to spot the fall of shot relative to the target for range. The bearing resolution was about 5-6* for the early sets. By 1943 they were developed to the point that the common problem of the reliability of vacuum tube electronics aboard warships was manageable, and they were well integrated into the advanced firecontrol systems of German warships. Their accuracy was also very good. The Germans didn't have a pressing need to replace these radars with more modern equipment like the Americans had with Mk3. They did however want to improve the performance over existing levels. In 1943 they introduced improved models with huge 3x6 meter antennas. These large antennas provided a beam width of about 3 degrees, and significant improvement in range to target attainment. These models also had improved signal processing circuitry which improved the range accuracy to 25 meters regardless of the range.
(...)
The German radars could be used to direct fire blind after about 1941-mid 1942. In a 1944 Naval Conference there is some concern about the increasing dependence on radar alone directed fire. Radar direction is so much easier to use and master. The concern was, that the proficiency with more traditional methods may become inadequate should the radar become disabled or non functional-as was the case with the Scharnhorst's forward radar at North Cape.

(...)
The performance of the British radars during this battle was rather mixed. Tovey wrote in his official report that none of the British destroyer's radars proved capable of detecting and tracking the German cruisers on their own. Only the type 271 radars on the destroyers were capable of holding the German cruisers after being "put on" the target after spotting visually the German gun flashes. It could not hold contact for long though, because the Hipper was operating at the extreme edge of 271's detection range to cruisers. Kummetz was trying (successfully) to lure the British destroyers away to the north with episodic firing and then jinking away to the north. He achieved his objective of forcing the convoy to turn into the Luetzow group to the southward, while damaging multiple British destroyers, and also keeping his own group's ships at a relatively safe distance.

Burnette first located the Hipper at about 11:05 hours from a range of 21km with the Sheffield's Type 273 radar. WWII radar expert Louis Brown reports that the British 50 cm radars that equipped the British ships during this battle were not capable of blind fire, because these were the older model Types 284/5 without lobe switching and not the newer pattern Type 284/5M models with lobe switching. This seems to be why Burnette was obliged to wait until he closed range to 12,000 yards and obtained visual bearing data before opening fire on Hipper. Tovey noted that an experimental British IFF system failed completely to operate as well. This didn't matter so much, because at the time of the British cruiser's timely arrival, the Hipper was highlighted by the artic twilight on the southern horizon and clearly identifiable from seven miles, while they remained hidden in the artic gloom to the northward. The Hipper's radar was preoccupied with the tasks of sinking the Achates and damaging the Obedient at the time.

The Jamaica's 273 radar was knocked out by the shock of its opening salvo, but Tovey noted that the ranging by the Types 284/5 50 cm radars were crucial to the British shooting, despite their limitations in bearing accuracy. Radar ranging was required due to the extreme weather conditions that rendered the optics mostly useless. They scored two, perhaps three hits on the Hipper. The German destroyer was sunk at point blank range as it mistook the British cruiser for the Hipper in the soup, and tried to join the British formation. Burnette must have gasped with relief when the German destroyer didn't launch torpedoes. In my opinion the German radar directed shooting was comparatively much more impressive thoughout. It had to perform in mostly blind conditions, at greater ranges, and against much more difficult to hit targets.

Radar does make possible quicker and more consistent straddling at longer ranges. The range accuracy of even the best optical range finders is typically 1% of the range. Radar is much more accurate. The American 40cm Mk3's accuracy was 0.1% of the range give or take 40 yards. The British 50cm Type 284M's range accuracy was 240 yards, or by using a corrective template to account for distortion toward the perimeter of the CRT; 120 yards.

Another advantage of radar over optics is the ability to better determine errors in the MPI of the salvo patterns. This boiled down to the ability to discriminate between the target and the shell splashes. The range resolution of the Mk3 was 400 yards, so echoes of the target and splashes could not be readily determined if they were within 400 yards of each other . The Type 284M was markedly better than the Mk3 with a range resolution of 150 meters. It could be better determined if the MPI wasn't squarely on the target, and correction could be made, improving the chances. Late war equipment with shorter pulse durations was better yet. Post war advances would have made possible fine corrections in MPI errors easier.

The German Seetakt radar was actually well suited to firecontrol because of its unique methods of measuring and displaying range data. In practice the operator held the pip on the null mark on the CRT and the correct range was continuously displayed, updated, and transmitted directly to the central firecontrol. The operator could zoom in on and closely examine any portion of the time base for observation purposes.

[Thoddy]

kannst du mal nen link zu dem Originalbeitrag legen?

der AVKS Bismarck Bericht legt nahe, dass zumindest einTeil der unbefriedigenden Richtungsbestimmung durch das Fumo auf die feste Verbindung zwischen Fumo und der Drehhaube zurückzuführen ist. Abhilfe könnte hier eine richtungsbewegliche Montage bringen, analog optischem E-Messer.

Wobei in Richtung optischem Emesser wird zusätzlich bemängelt, daß der separate Seitenrichtbereich für das kreiselstabilisierte EM-Gerät zu klein sei, so daß bei scharfen Richtungsänderungen der Kontakt zum Ziel verloren gehen kann. Desweitern wurde Schwergängigkeit der Drehhaube bemängelt. Gelöst werden konnte dies zunächst teilweise auf Kosten zusätzlichen Spiels (und damit verschlechterung der Richtungsortung) in der mechanischen Übertragung.

Ich würde sagen ein Teil der im AVKS Bismarck genannten Empfehlungen zur Verbesserung der Funkmess-ortung und
-richtungsbestimmung, dürfte sich mit "Bordmitteln" ohne zusätzlich großen technischen Aufwand umsetzen lassen, insbesondere wenn es um Nacharbeitung im mechanischen Teil der Anlagen geht.

Edith
irgendwo gibt es zu lesen, daß, wenn man mit dem auf der Drehhaube montierten Seetakt über ein Ziel geht, waren mehrfach Sprünge in den  Funkmessausschlägen zu verzeichnen waren und das man die erkannten Hauptzacken durch "Zurückdrehen" der Drehhaube teilweise nicht wieder finden konnte.
auf 20 000 m hat ein Ziel von 200m Quer Ausdehnung eine Richtungsausdehnung von rund 1 Grad

mehrere Echos von ein und demselben Ziel könnten bedeuten, das das Funkmessgerät innerhalb des 1 Grad Bereiches auflösen kann, das  im AVKS-Bericht festgestellt Problem war zu einem guten Teil bei der Drehhaube zu suchen, die selber ein ein mechanisch bedingtes Spiel hat, somit können ggf Rückstrahlquellen, einfach weil sie kleiner sind als das Spiel der Drehaubenmaschinerie scheinbar völlig verschwinden. Der Funkmessoperator kann daher aufgrund des mechanischen Spiels im Systems nicht immer einen optimalen Reflexionskontakt finden und vor allem auch nicht dauerhaft halten. Für den Feuerleitrechner sind jedoch Sprünge der Tod, da dann eine brauchbare Rechengrundlage nicht zu erreichen ist.

Sprünge in den Funkmessausschlägen sind dadurch erklärbar, das nicht jede Teilstruktur eines Schiffes dasselbe Reflexionsvermögen für elektromagnetische Wellen besitzt und vor allem nicht überall "optimale" Reflexionsfläche vorhanden ist. (optimal im Sinne des Funkmessnutzers)

Besonders gute Radarreflektoren sind im Winkel von 90 Grad zueinander angeordnete Metall-Strukturen.

Meiner Meinung nach müßten sich die zugehörigen Arbeiten entsprechend der Empfehlungen im AVKS Bericht im KTB von Tirpitz finden lassen.

[Matrose71]

@ Thoddy

Der original Beitrag:
http://www.ww2aircraft.net/forum/ww2-general/best-world-war-two-warships-3592-45.html
Es geht los mit Beitrag 662 und die Diskussion erstreckt sich über die nächsten 4 Seiten bis zum Ende des Threads.

Für mich neu an der Sache war einmal, dass das deutsche Seetakt Radar sozusagen ein "All in one" Gerät war, dass gleichzeitig mehrere Aufgaben abdeckte.
Suchradar, Flugabwehrradar und Artillerieradar. Darüber hinaus war mir neu, daß es mit dem deutschen Radar möglich war ab 1942 die SA alleine zu steuern.

Bisher dachte ich immer, dass die Richtungsbestimmung zu schlecht war und das Radar ausschließlich zur Entfernungsmessung benutzt wurde, um diese Ergebnisse in die Feuerleitlösung zu integrieren, dass das deutsche Radar das auch alleine schaffte war mir neu.
In der ganzen Diskussion kam auch heraus, dass das Seetakt trotz seiner großen Welle (50cm) wohl sehr genau arbeitete und wesentlich bessere Ergebnisse erziehlte als Alliierte 50cm Geräte. Die Probleme die man mit der großen Welle und der Richtungsbestimmung hatte , behalf man sich mit sehr großen Antennen um die 6m. Davon brauchte man aber 2 um sowohl den Frontbereich als auch den Heckbereich umfassend beobachten und messen zu können, da sich diese Antennen nicht wie die Alliierten um die eigene Achse drehen konnte.

Sowohl in der Barentsee als auch am Nordkap hat das Seetakt wohl gute Ergebnisse geliefert, leider konnte SH nur mit einem Radarteil und dem hinteren Turm arbeiten, da sie die andere Antenne schon durch Norfolk verloren hatte. Allerdings brauchte SH wohl mit dem hinteren Turm und der gut arbeitenden Radaranlge jeweils nur 1-2 Salven um deckend im Ziel zu liegen.

[delcyros]

In dieser Hinsicht ist auch BISMARCK wichtig, um auf die ursprüngliche Frage zurückzukommen. Hatte sie spezielle Nachtoptik EM wie SCHARNHORST?
Oder nutzte sie radargeleitetes Feuer um die Zerstörer im Nachtgefecht anzugreifen?
In den englischen after ation reports sagen deren Kommandanten aus, dass BISMARCK ohne seine Scheinwerfer zu nutzen oder Leuchtgeschosse abzufeuern auf die englischen Zerstörer Schoß. Dabei beobachtete man Mündungsfeuer, gefolgt von Ruhe wonach jeweils Einschläge in deren Nähe (tw. mit Eingabelungen) folgten. Von britischer Seite aus vermutete man, dass BISMARCK blind radargeleitet schoß. Sollte diese Vermutung zutreffen, wäre das der erste Fall von radargeleitetem Blindfeuer.
Ohne Kenntniss der Ausrüstung sind aber auch andere Erklärungen denkbar...

[Hexe]

Ein kleiner Beitrag zur Funkmeßortung Bismarck
https://wetransfer.com/downloads/33260aa8b7e15682669d73a4922cbb4620211019142218/3c0b38

Gruß Bernd

[M-54842]

Danke für den Beitrag.

[Peter K.]

 
Herzlichen Dank!