198:
404:
514:
246:
600:
254:
608:
575:, which was cleared for service use in 1958, and came into operational use in the Shackleton Mk 2 and 3 beginning in 1959. ASV21 could detect a submarine schnorkel at 15 nautical miles (28 km) "in very favourable conditions but at much shorter range in the sea states normally experienced in the North Atlantic." ASV21 was generally similar to the earlier designs. ASV21 was also selected for the Mark II models of the
237:. This amplified the radar's pulses and played them into the radio operator's headphones. It provided this warning long before the echos from the submarine became visible on the aircraft's display. With experience, the operators could tell whether the aircraft was approaching or just flying by, allowing the U-boat to dive and escape detection. By the end of 1942, Mark II had been rendered ineffective.
129:
380:
approached the U-boat, hopefully fooling the radio operator into believing they were flying away. Mark VI never fully replaced Mark III in service, as truly effective detectors did not become available until the U-boat fleet had largely been destroyed. The failure of Naxos and later devices led to morale problems in the U-boat force.
301:'s began arriving in March 1943, and had largely replaced the Mark II in front-line units by the end of the summer. The Germans had no way to detect these signals, and their submarines were repeatedly attacked with no warning. The losses were so great they took to leaving port in the day, but the RAF responded with
317:
The reason for the long delay in discovering Mark III is somewhat surprising given that a magnetron from H2S fell into German hands almost immediately after it was first used in
February 1943. Sources disagree on the reason; the magnetron was either unknown to the German Navy, or they did not believe
313:
that allowed them to detect the submarines at as much as 90 miles (140 km). This led to an urgent 13 August 1943 message from German Naval High
Command ordering that submarines turn off their Metox. This incredible deception not only further delayed the German discovery of the true nature of the
211:
For a variety of reasons, the 1.5 m wavelength of the radar system worked better over water than land, and the large size and flat vertical sides of the ships made excellent radar targets. Production quality sets were available in 1939 and entered operational service in early 1940, becoming the
532:
Adding to the problem was the loss of the large numbers of
Liberator aircraft with the ending of lend-lease. These had been used as very long-range patrol aircraft during the war, and their return to the US left Coastal Command with no suitable airframes to cover the GIUK gap. A solution was found
662:
and being the first generation of ASV radars to include modern signal and data processing (digital as well as analogue)". This gave
Searchwater a better ability than ASV13 or ASV21 to detect small targets such as submarine periscopes against a background of strong sea returns. The radar screen for
375:
was unsuitable for bombing operations, the Air
Ministry ordered Coastal Command to take over their existing orders in spite of them having a shorter range that was unsuitable for closing the Gap. Coastal Command was able to have the radar switched to the ASG, which they operated under the name ASV
308:
The
Germans spent much of the rest of the year using radar detectors at longer wavelengths in a fruitless attempt to find the new ASV. Further confusion was added by a captured Coastal Command pilot, who related that ASV was no longer used for search, but only in the last minutes of the approach.
565:) of about 40 nautical miles (74 km) for a destroyer, 20 nautical miles (37 km) for a surfaced submarine, and 8 nautical miles (15 km) for a submarine conning tower. "In rougher conditions, the range would be much less." By 1958, ASV13 was considered "old and rather unreliable".
379:
The TRE was sure the
Germans would soon detect Mark III and render it ineffective as well, so they responded with a new ASV Mark VI that was essentially a more-powerful Mark III. The key trick to Mark VI was the "Vixen" device that allowed the operator to progressively mute the output as they
224:
that lit up the submarines during the last seconds of the approach. By early 1942, Mark II and the Leigh Light were finally available on large numbers of aircraft. Their effect was dramatic; German U-boats had previously been almost completely safe at night, and could operate out of the
215:
These designs had a relatively long minimum range, meaning the submarine targets disappeared from the display just as the aircraft was readying for the attack. At night, this allowed the submarines to escape attack by maneuvering when an aircraft could be heard. This was solved by the
615:
The war-era radar classifications became less relevant in the 1970s as radar units increasingly became multi-purpose as opposed to being single-role. Newer designs, even dedicated naval surveillance designs, were not assigned numbers in the ASV lineage. The first such example is the
347:
in a matter of weeks. US development was not subject to the infighting in the RAF, but suffered its own series of setbacks and confusion. The early DMS-1000 proved to be an excellent unit, but for reasons unknown, the US War
Department decided to put the inferior
173:
was hand held outside one of the escape hatches and rotated looking for when the signal disappeared, indicating the antenna was aligned with the target ship. This was not easy as the signal naturally fluctuated. The first successes were in August 1937.
326:
to track the RAF's H2S radars. Naxos provided very short detection range, about 8 kilometres (5.0 mi), too short to be really useful. Better detectors arrived very late in the war, but by that time the U-boat force had largely been destroyed.
498:. This was a very simple system originally intended to indicate a selected range to the pilot, which proved very useful for timing bomb drops. Trials were carried out in August 1944 and experimental fits were made to the Beaufighter, Mosquito and
229:
in spite of it being close to
British shores. By the spring of 1942, Biscay was increasingly dangerous, with aircraft appearing out of nowhere in the middle of the night, dropping bombs and depth charges, and then disappearing again in moments.
395:, while the US version based on ASG was known as AN/APS-15 and given the UK designation ASV Mark X. It was expected the latter would be available in December 1943. The similar AN/APS-3 was mounted to Catalinas and named ASV Mark VIII.
560:
so the image did not change when the aircraft manoeuvred, and the use of a pressurised radome that kept out humidity and made it suitable for use in tropical areas. ASV13 was a centimetric radar with a detection range in a calm sea
632:
at long range from their carrier ships. It has since been sold around the world and used in a variety of roles. The latest versions, Seaspray 7000, are completely rebuilt and share only the name with the original models.
64:
in 1937. For a variety of reasons, ASV was easier to develop than the air-to-air variety of the same systems, and the first operational use of the Mark I followed in early 1940. A cleaned-up and repackaged version,
212:
first radar system to be mounted on an aircraft in a combat setting. A somewhat improved version, Mark II, followed in 1941, which saw tens of thousands of units produced in the UK, Canada, US and
Australia.
490:, had the problem that the fitting of ASV required the removal of some other devices to make room. Previously they had carried a long-distance radio for remaining in contact with their base, as well as a
41:(RAF) to refer to a series of aircraft-mounted radar systems used to scan the surface of the ocean to locate ships and surfaced submarines. The first examples were developed just before the opening of
494:
system for navigation. Neither could be safely removed, and the desire for a much smaller ASV for this role developed. This was fulfilled with the Mark XVI, built in the US as LHTR and supplied under
411:
In October 1944, the Germans introduced two innovations that were extremely worrying. One was the introduction of new classes of U-boats with much higher performance, and the other was the use of the
371:, and an example of this aircraft with the DMS-1000 was sent to the UK for testing in early 1942. Another 30 arrived with a mix of DMS-1000, SCR-517 and ASG. However, when Bomber Command decided the
271:
in early 1940 led to efforts to develop microwave-frequency versions of the various radars then in use, including a new ASV under the name ASVS for "Sentimetric". A prototype was available from
383:
Another solution to the problem of being detected was to change frequencies. From 1943, both the UK and US began developing magnetrons that worked on even shorter wavelengths, first in the
640:, which was designed to replace the Mk. 21 in a new version of the Nimrod, the MR2. These began arriving in 1979. In 1978, the Royal Navy retired its fleet carriers, losing the
92:, which the Germans were unable to detect until the U-boat fleet had already been decimated. A series of other ASVs were developed for different aircraft as the war progressed.
424:
On 22 November 1944, it was decided to deploy new 3 cm-band ASV's, with both the UK and US developing versions. However, these demonstrated poor performance against the
177:
After several successful flights over the summer, Watt asked the team if they could be ready for a demonstration in September. On 4 September, the system was used to detect
363:
The RAF decided that UK-built aircraft would be fitted with their Mk. III, while any US aircraft in British service would use US sets. Initially, they planned on using the
863:
The airborne radar group now had two major projects, the detection of ships, (ASV, Air to Surface Vessels) and the interception of aircraft (AI, Aircraft Interception).
417:, allowing even older types to spend most of their time submerged. This made the X-band versions of ASV a requirement, as they had the resolution needed to detect the
142:
Development of the original ASV systems started in 1937 after the team testing an experimental air-to-air radar noticed odd returns while flying near the shore of the
1556:
305:
patrols and losses shot up once again. In August, shipping losses to submarines was the lowest since November 1941, and more U-boats were sunk than cargo ships.
529:
led to a rapid re-evaluation of this stance, especially as the Soviets were known to be introducing new submarines surpassing even the late-war German designs.
197:
1338:
1244:
1174:
428:, and experiments with these new systems were still underway when the war ended. In the immediate post-war era, development of the system continued as an
249:
The Mark III's small antenna was installed in a well-streamlined radome on the nose of the Wellington, forcing the removal of the guns in that location.
181:
ships on manoeuvres in almost complete overcast. The weather was so bad they had to use the radar pattern from local sea-side cliffs to navigate home.
80:
with rapidly increasing success. As German U-boat losses shot up in 1942, they concluded the RAF was using radar to detect them and responded with the
1472:
Smith, R.A.; Hanbury-Brown, Robert; Mould, A.J.; Ward, A.G.; Walker, B.A. (October 1985). "ASV: the detection of surface vessels by airborne radar".
651:
helicopter that was able to operate from a variety of ships. Several greatly improved versions followed, part of the Searchwater 2000 series.
1441:
1221:
257:
With the radome of the Mark III well streamlined, the Leigh light installation was also cleaned up by placing it in a retractable "dustbin".
1199:
were rapidly converted first for air-sea rescue duties and then, with the addition of ASV 13 radar, to the general reconnaissance role."
525:
in 1945, the British believed another war was at least a decade off, and put little effort into new radar systems. The opening of the
107:. By the late 1960s the original terminology was no longer being used, and the last major entries in the series were known simply as
1532:
1511:
1462:
1420:
1394:
1433:
Watching the skies: a history of ground radar for the air defence of the United Kingdom by the Royal Air Force from 1946 to 1975
658:, which was a technology developed during World War II. "Searchwater was a completely new concept, having a high power wideband
663:
Searchwater could be viewed in daylight, unlike the screen of ASV21, which was viewed in a radar 'tent' on board the aircraft.
583:
of the Argus Mark I's. The Argus was widely described as the best anti-submarine aircraft of its era. ASV21D also equipped the
513:
447:, which had previously used the early Mark II radars, the Mark X was further adapted as the Mark XI. This used a new narrow
403:
372:
364:
54:
591:
in the Nimrod MR 2 starting in 1980. ASV 21 remained in service on the Argus until the last example retired in 1981.
774:
ASV Mark X - RAF name for US ASD-1/APS-15 X-band system; used primarily on Liberators; not to be confused with ASVX
147:
740:
ASV Mark VIA - added lock-follow which could direct the Leigh light, a separate pilot indicator, and blind-bombing
603:
Radar returned to the nose in the Nimrod, with this MR2 showing no outward sign of the Searchwater radar within.
245:
1551:
701:
Mark IIIB - Mk. IIIA with internal modifications allowing the same unit to be used by Coastal or Bomber command
344:
792:
ASV Mark XIII - modified Mk. XI for Mosquito, Beaufighter and Brigand; did not enter service before war ended
647:
aircraft. A new version of Searchwater, the LAST, was created to provide this coverage when mounted under a
189:
later commented that "This, had they known, was the writing on the wall for the German Submarine Service."
644:
584:
310:
807:
ASV Mark XV - miniaturized version of XI; did not enter service but acted as the basis for future designs
576:
472:
463:
rockets with armor-piercing warheads to damage or puncture the U-boat making it impossible to dive, and
517:
The Shackleton MR2 moved its Mark 13 radar to the ventral position in a well-streamlined installation.
319:
279:
234:
182:
166:
151:
150:
miles south of them. Shipping also appeared, but the team was unable to test this very well as their
81:
50:
599:
782:
ASV Mark XI - originally known as ASVX, X-band design for Barracuda but used primarily on Swordfish
659:
641:
476:
291:
53:
classification, which includes similar radars in ground and ship mountings. And it constrasts with
751:
392:
253:
60:
The first ASV was developed after the accidental detection of wharves and cranes while testing an
572:
553:
542:
287:
158:
104:
100:
96:
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1458:
1437:
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1185:
786:
648:
629:
588:
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in the summer of 1942, but they predicted it would not be widely available until summer 1943.
76:
at night, but the target had to be seen to be attacked, a problem that was addressed with the
1481:
1313:
705:
617:
491:
444:
368:
349:
268:
186:
112:
69:, replaced it at the end of the year, but the system was not widespread until late in 1941.
607:
820:
796:
549:
502:
480:
302:
46:
38:
318:
it could be used against U-boats. It was not until late 1943 that a naval version of the
762:
ASV Mark VIII - RAF name for US AN/APS-3 radars; used mainly on Catalinas from June 1944
1196:
811:
754:- largely similar to Mk. III but operating in the X-band at 3 cm; not widely used
557:
538:
534:
487:
429:
340:
170:
1545:
1524:
Airborne Maritime Surveillance Radar: Volume 2, Post-War British ASV Radars 1946-2000
1160:
Airborne Maritime Surveillance Radar: Volume 2, Post-War British ASV Radars 1946-2000
621:
499:
388:
336:
323:
226:
1503:
Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
1073:
Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
1029:
Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
1405:
692:
522:
468:
452:
298:
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suggested a new ASV could be quickly introduced by making minor changes to the new
262:
89:
42:
233:
The Germans ultimately solved the problem of Mark II with the introduction of the
1522:
1501:
1452:
1431:
1384:
765:
734:
713:
681:
637:
437:
221:
217:
206:
201:
The antenna array of the Mark II was quite large and produced considerable drag.
108:
77:
66:
128:
723:
675:
495:
178:
162:
132:
1485:
1353:
1259:
1189:
816:
ASV Mark 19A - made by Echo for the Royal Navy Gannet and Sea Prince aircraft
687:
ASV Mark IIA - Mk. II with more powerful 100 kW transmitter; 12 produced
611:
Seaspray on the Lynx was an export success, seen here in the Royal Thai Navy.
391:
at 1.25 cm. The UK-developed 3 cm version for the Liberator became
737:- high-power Mk. III with 200 kW magnetron, "Vixen", and stabilization
655:
580:
433:
283:
272:
143:
85:
548:
A more suitable custom-built patrol aircraft was a priority and led to the
726:- RAF name for US APG (AN/APS-2) radars used on Liberators and Fortresses
57:, which is used to detect flying aircraft rather than sea-suface vessels.
769:
717:
625:
526:
61:
17:
1212:
McLelland, Tim (ed.), "Avro Shackleton, the RAF's Cold War Sub Hunter",
456:
850:
695:- centimetric radar based on H2S; widely used from March 1943 onwards
467:
to mark the location for follow-up attacks by other aircraft carrying
407:
The Swordfish mounted the ASV Mark XI radome between its landing gear.
819:
ASV Mark 21 - new design by EMI used on Canadair CP-107 Argus Mk II,
448:
384:
353:
73:
541:
had become passé by this point, and these units were referred to as
471:. Further developments of this system led to the Mark XIII, used on
95:
In the post-war era, several new ASV radars were developed, notably
606:
598:
512:
464:
402:
357:
252:
244:
196:
146:. They eventually realized these were the docks and cranes at the
127:
849:
Hanbury Brown, R.; Minnett, H.C.; White, F.W.G. (November 1992).
314:
problem but also allowed Mark II to once again become effective.
309:
Instead, their aircraft were using a receiver tuned to the Metox
278:
It was at this point that the Metox started to become effective.
460:
810:
ASV Mark XVI - RAF name for US LHTR, a range-only unit used by
537:
bombers with Mark VII to become the Lancaster GR.3. The use of
486:
The Beaufighter, which became one of Coastal Command's primary
286:, mostly to the antenna. This started a furious debate between
1406:"H2S Radar in Bomber Command and ASV Radar in Coastal Command"
568:
1216:, no. Icons No 21, Key Publishing Ltd, pp. 20, 33,
1366:
1121:
1109:
1053:
886:
587:
when it came into service in 1970, and was replaced by the
322:
arrived, having originally been developed to allow German
165:
that were able to fly out over the North Sea from nearby
138:
demonstrated ASV in commanding fashion in September 1937.
1413:
Canadians on Radar: Royal Canadian Air Force 1940 - 1945
995:
993:
991:
851:"Edward George Bowen: 14 January 1911–12 August 1991"
698:
Mark IIIA - improved version available from late 1943
1271:
1269:
855:
Biographical Memoirs of Fellows of the Royal Society
826:
ASV Mark 21D - modified version fitted to Nimrod MR1
757:
ASV Mark 7A - post-war version used on Lancaster GRs
624:. This was originally developed in concert with the
1238:
1236:
1234:
1232:
720:; largely withdrawn by late 1943 in favour of Mk. V
360:, the ASG, which was much better than the SCR-517.
678:- 1.5 m VHF, 300 prototype sets built in 1940
459:impossible, so these aircraft were fit with eight
684:- production version of Mark I; ~23,000 produced
743:ASV Mark VIB - production version of the Mk. VIA
1066:
1064:
1062:
1022:
1020:
746:ASV Mark VIC - version of Mk. VI for Sunderland
455:. The radome's location made the carriage of a
1282:The Shackleton Association (thegrowler.org.uk)
556:. The main improvements were the addition of
290:, who wanted every H2S for their bombers, and
620:, a small unit designed to be mounted on the
45:and they have remained a major instrument on
8:
352:SCR-517 into production instead. Meanwhile,
1307:
1305:
1303:
1301:
1299:
1297:
1278:"Ballykelly – The Shackleton Era 1952-1971"
297:After several changes in policy, the first
37:for short, is a classification used by the
1346:Royal Air Force Historical Society Journal
1318:Defence Electronics History Society (DEHS)
1252:Royal Air Force Historical Society Journal
1245:"Maritime Patrol in the Piston Engine Era"
1207:
1205:
1182:Royal Air Force Historical Society Journal
1175:"Maritime Patrol in the Piston Engine Era"
387:at 3 cm wavelength, and later in the
367:, which had the range to operate over the
294:, who wanted them for submarine hunting.
49:since that time. It is part of the wider
982:
795:ASV Mark 13A - post-war version used on
777:ASV Mark XA - APS-5A, minor improvements
552:. The Shackleton Mk 1 and 2 mounted the
841:
1097:
1085:
1041:
1011:
999:
970:
958:
946:
934:
922:
768:- RAF name for US ASH, later known as
1557:Military radars of the United Kingdom
1454:Echoes of War: The Story of H2S Radar
1145:
1133:
910:
898:
874:
823:, and retrofitted to Shackleton Mk 2,
343:, and local development began at the
84:. The RAF responded by deploying the
7:
628:missile to allow the Lynx to attack
1314:"2018 Russell Burns Spring Lecture"
545:, remaining in service until 1954.
533:by adapting surplus Bomber Command
729:ASV Mark VA - improved ASG.3/APS-2
335:The magnetron was revealed to the
25:
451:that fit between the Swordfish's
356:had been developing a system for
169:. The testing was crude; a small
154:was forbidden to fly over water.
55:aircraft interception (AI) radar
789:for Beaufighter strike fighters
1:
1383:Bowen, Edward George (1998).
436:even if they did not carry a
157:To further test the concept,
72:ASV was useful for detecting
1521:Watts, Simon (August 2018).
1500:Watts, Simon (August 2018).
31:Radar, Air to Surface Vessel
1411:. In Grande, George (ed.).
1312:Bruton, Liz (6 July 2018),
585:Hawker Siddeley Nimrod MR 1
432:system, as it could detect
373:Boeing B-17 Flying Fortress
365:Consolidated B-24 Liberator
161:provided the team with two
1573:
260:
204:
1527:. Morgan & Claypool.
1506:. Morgan & Claypool.
579:, replacing the American
571:developed a replacement,
1486:10.1049/ip-a-1.1985.0071
1451:Lovell, Bernard (1991).
785:ASV Mark XII - modified
704:Mark IIIC - Mk. III for
443:In order to upgrade the
345:MIT Radiation Laboratory
267:The introduction of the
27:RAF radar classification
1404:Campbell, W.P. (2000).
636:Another example is the
331:Other WWII developments
1214:Aeroplance Illustrated
804:ASV Mark XIV - unknown
716:- RAF name for the US
671:From Watts and Smith:
645:airborne early warning
612:
604:
518:
473:de Havilland Mosquitos
408:
311:intermediate frequency
258:
250:
202:
139:
1337:Coleman, Ian (2005).
1195:This says that "some
1136:, pp. 22–23, 35.
799:, and Shackleton Mk 2
654:ASV13 and ASV21 used
610:
602:
577:Canadair CP-107 Argus
516:
509:Post-war developments
406:
399:Late-war developments
256:
248:
200:
131:
1430:Gough, Jack (1993).
1243:Tyack, Bill (2005).
1173:Tyack, Bill (2005).
477:Bristol Beaufighters
320:Naxos radar detector
280:Robert Hanbury Brown
235:Metox radar detector
183:Albert Percival Rowe
167:RAF Martlesham Heath
152:Handley Page Heyford
82:Metox radar detector
51:surface-search radar
1162:. pp. 2-1–2-7.
1014:, pp. 165–167.
642:Fairey Gannet AEW.3
573:ASV Mark 21 (ASV21)
554:ASV Mark 13 (ASV13)
521:With the ending of
339:in 1940 during the
292:RAF Coastal Command
1254:(33): 73, 75, 80.
985:, p. XVII-10.
708:using two scanners
613:
605:
595:Later developments
519:
409:
288:RAF Bomber Command
259:
251:
203:
159:Robert Watson-Watt
140:
1474:IEE Proceedings A
1443:978-0-11-772723-6
1367:Smith et al. 1985
1223:978-1-910415-22-1
1122:Smith et al. 1985
1110:Smith et al. 1985
1054:Smith et al. 1985
887:Smith et al. 1985
787:AI Mk. VIII radar
649:Westland Sea King
630:fast attack craft
589:Searchwater radar
119:WWII developments
16:(Redirected from
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369:Mid-Atlantic Gap
350:Western Electric
269:cavity magnetron
187:Tizard Committee
62:air-to-air radar
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1494:Further reading
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1052:
1048:
1040:
1036:
1026:
1025:
1018:
1010:
1006:
998:
989:
981:
977:
969:
965:
957:
953:
945:
941:
933:
929:
921:
917:
909:
905:
897:
893:
885:
881:
873:
869:
848:
847:
843:
838:
833:
821:Shackleton Mk 3
812:strike fighters
797:Shackleton Mk 1
669:
660:TWT transmitter
597:
550:Avro Shackleton
511:
488:strike fighters
401:
333:
303:strike aircraft
265:
243:
209:
195:
126:
124:Initial concept
121:
47:patrol aircraft
39:Royal Air Force
28:
23:
22:
15:
12:
11:
5:
1570:
1568:
1560:
1559:
1554:
1544:
1543:
1540:
1539:
1533:
1518:
1512:
1495:
1492:
1491:
1490:
1480:(6): 359–384.
1469:
1463:
1448:
1442:
1427:
1421:
1401:
1395:
1378:
1375:
1372:
1371:
1359:
1329:
1293:
1265:
1228:
1222:
1201:
1165:
1158:Watts (2018).
1150:
1138:
1126:
1124:, p. 384.
1114:
1112:, p. 377.
1102:
1100:, p. 247.
1090:
1088:, p. 246.
1078:
1075:. p. 8-3.
1071:Watts (2018).
1058:
1056:, p. 371.
1046:
1044:, p. 166.
1034:
1031:. p. 8-2.
1027:Watts (2018).
1016:
1004:
1002:, p. 165.
987:
975:
973:, p. 163.
963:
961:, p. 159.
951:
949:, p. 158.
939:
937:, p. 157.
927:
925:, p. 156.
915:
913:, p. 209.
903:
891:
889:, p. 360.
879:
867:
840:
839:
837:
834:
832:
829:
828:
827:
824:
817:
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772:
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721:
711:
710:
709:
702:
699:
690:
689:
688:
679:
668:
665:
596:
593:
539:Roman numerals
535:Avro Lancaster
510:
507:
430:air-sea rescue
400:
397:
341:Tizard Mission
332:
329:
324:night fighters
261:Main article:
242:
239:
205:Main article:
194:
191:
171:dipole antenna
125:
122:
120:
117:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1569:
1558:
1555:
1553:
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1547:
1536:
1534:9781643270692
1530:
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1513:9781643270661
1509:
1505:
1504:
1498:
1497:
1493:
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1475:
1470:
1466:
1464:9780852743171
1460:
1457:. CRC Press.
1456:
1455:
1449:
1445:
1439:
1435:
1434:
1428:
1424:
1422:9780968759608
1418:
1414:
1407:
1402:
1398:
1396:9780750305860
1392:
1389:. CRC Press.
1388:
1387:
1381:
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1376:
1368:
1363:
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1319:
1315:
1308:
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1302:
1300:
1298:
1294:
1283:
1279:
1276:Hill, David,
1272:
1270:
1266:
1261:
1257:
1253:
1246:
1239:
1237:
1235:
1233:
1229:
1225:
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1202:
1198:
1191:
1187:
1183:
1176:
1169:
1166:
1161:
1154:
1151:
1148:, p. 43.
1147:
1142:
1139:
1135:
1130:
1127:
1123:
1118:
1115:
1111:
1106:
1103:
1099:
1094:
1091:
1087:
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1055:
1050:
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1038:
1035:
1030:
1023:
1021:
1017:
1013:
1008:
1005:
1001:
996:
994:
992:
988:
984:
983:Campbell 2000
979:
976:
972:
967:
964:
960:
955:
952:
948:
943:
940:
936:
931:
928:
924:
919:
916:
912:
907:
904:
901:, p. 45.
900:
895:
892:
888:
883:
880:
877:, p. 38.
876:
871:
868:
864:
860:
856:
852:
845:
842:
835:
830:
825:
822:
818:
815:
813:
809:
806:
803:
798:
794:
793:
791:
788:
784:
781:
776:
775:
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771:
767:
764:
761:
756:
755:
753:
750:
745:
742:
739:
738:
736:
733:
728:
727:
725:
722:
719:
715:
712:
707:
703:
700:
697:
696:
694:
691:
686:
685:
683:
680:
677:
674:
673:
672:
666:
664:
661:
657:
652:
650:
646:
643:
639:
634:
631:
627:
623:
622:Westland Lynx
619:
609:
601:
594:
592:
590:
586:
582:
578:
574:
570:
566:
564:
559:
558:stabilization
555:
551:
546:
544:
540:
536:
530:
528:
524:
515:
508:
506:
504:
501:
500:Fleet Air Arm
497:
493:
489:
484:
482:
478:
474:
470:
469:depth charges
466:
462:
458:
454:
450:
446:
441:
439:
435:
431:
427:
422:
420:
416:
415:
405:
398:
396:
394:
390:
386:
381:
377:
374:
370:
366:
361:
359:
355:
351:
346:
342:
338:
337:United States
330:
328:
325:
321:
315:
312:
306:
304:
300:
295:
293:
289:
285:
281:
276:
274:
270:
264:
255:
247:
240:
238:
236:
231:
228:
227:Bay of Biscay
223:
219:
213:
208:
199:
193:Mark I and II
192:
190:
188:
184:
180:
175:
172:
168:
164:
160:
155:
153:
149:
148:Harwich docks
145:
137:
134:
130:
123:
118:
116:
114:
110:
106:
102:
98:
93:
91:
87:
83:
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70:
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63:
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48:
44:
40:
36:
32:
19:
1523:
1502:
1477:
1473:
1453:
1432:
1412:
1385:
1377:Bibliography
1362:
1345:
1332:
1321:, retrieved
1317:
1285:, retrieved
1281:
1251:
1213:
1181:
1168:
1159:
1153:
1141:
1129:
1117:
1105:
1093:
1081:
1072:
1049:
1037:
1028:
1007:
978:
966:
954:
942:
930:
918:
906:
894:
882:
870:
862:
858:
854:
844:
752:ASV Mark VII
693:ASV Mark III
670:
653:
635:
614:
567:
547:
531:
523:World War II
520:
485:
453:landing gear
442:
425:
423:
418:
413:
410:
393:ASV Mark VII
382:
378:
362:
334:
316:
307:
299:ASV Mark III
296:
277:
266:
263:ASV Mark III
232:
214:
210:
176:
156:
141:
135:
94:
90:ASV Mark III
71:
59:
43:World War II
34:
30:
29:
1098:Lovell 1991
1086:Lovell 1991
1042:Lovell 1991
1012:Lovell 1991
1000:Lovell 1991
971:Lovell 1991
959:Lovell 1991
947:Lovell 1991
935:Lovell 1991
923:Lovell 1991
766:ASV Mark IX
735:ASV Mark VI
714:ASV Mark IV
682:ASV Mark II
667:System list
638:Searchwater
563:Sea State 1
543:ASV Mark 7A
438:transponder
222:searchlight
218:Leigh Light
207:ASV Mark II
163:Avro Ansons
109:Searchwater
105:ASV Mark 21
101:ASV Mark 13
97:ASV Mark 7A
88:-frequency
78:Leigh light
67:ASV Mark II
1546:Categories
1386:Radar Days
1348:(33): 93.
1184:(33): 68.
1146:Gough 1993
1134:Gough 1993
911:Bowen 1998
899:Bowen 1998
875:Bowen 1998
831:References
724:ASV Mark V
706:Sunderland
676:ASV Mark I
656:magnetrons
496:lend-lease
434:life rafts
179:Royal Navy
133:Avro Anson
1354:1361-4231
1260:1361-4231
1190:1361-4231
836:Citations
581:AN/APS-20
426:schnorkel
419:schnorkel
414:schnorkel
284:H2S radar
273:Metrovick
144:North Sea
86:microwave
35:ASV radar
18:ASV radar
1436:. HMSO.
1339:"Nimrod"
1323:5 August
1287:6 August
770:AN/APS-4
718:DMS-1000
626:Sea Skua
618:Seaspray
527:Cold War
503:Avengers
376:Mark V.
241:Mark III
113:Seaspray
457:torpedo
185:of the
74:U-boats
1531:
1510:
1461:
1440:
1419:
1393:
1352:
1258:
1220:
1188:
861:: 47.
465:flares
449:radome
389:K-band
385:X-band
358:blimps
354:Philco
1409:(PDF)
1342:(PDF)
1248:(PDF)
1178:(PDF)
136:K8758
33:, or
1529:ISBN
1508:ISBN
1459:ISBN
1438:ISBN
1417:ISBN
1391:ISBN
1350:ISSN
1325:2020
1289:2020
1256:ISSN
1218:ISBN
1186:ISSN
479:and
461:RP-3
220:, a
111:and
103:and
1482:doi
1478:132
569:EMI
492:Gee
1548::
1476:.
1415:.
1344:.
1316:,
1296:^
1280:,
1268:^
1250:.
1231:^
1204:^
1180:.
1061:^
1019:^
990:^
859:38
857:.
853:.
505:.
483:.
475:,
440:.
421:.
115:.
99:,
1537:.
1516:.
1488:.
1484::
1467:.
1446:.
1425:.
1399:.
1369:.
1356:.
1262:.
1192:.
561:(
20:)
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