194:
400:
510:
242:
625:
250:
596:
571:, 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
233:. 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.
125:
376:
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.
297:'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
313:
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
309:
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
207:
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
528:
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
658:
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
371:
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
304:
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.
561:) 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".
375:
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
220:
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
211:
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
603:
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
343:
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
169:
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.
322:
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.
494:. 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
225:
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.
391:, 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.
556:
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
620:
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.
60:
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,
208:
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.
486:, 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
490:
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
407:
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
367:, 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
267:
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
379:
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
636:, 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
88:, 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.
420:
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
173:
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
359:
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
413:, 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
138:
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
1526:
301:
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.
525:
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.
193:
1308:
1214:
1144:
424:, 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
245:
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.
177:
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.
76:
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
1442:
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".
647:
helicopter that was able to operate from a variety of ships. Several greatly improved versions followed, part of the Searchwater 2000 series.
1411:
1191:
253:
With the radome of the Mark III well streamlined, the Leigh light installation was also cleaned up by placing it in a retractable "dustbin".
1169:
were rapidly converted first for air-sea rescue duties and then, with the addition of ASV 13 radar, to the general reconnaissance role."
521:
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
103:. By the late 1960s the original terminology was no longer being used, and the last major entries in the series were known simply as
1502:
1481:
1432:
1390:
1364:
1403:
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
654:, which was a technology developed during World War II. "Searchwater was a completely new concept, having a high power wideband
659:
Searchwater could be viewed in daylight, unlike the screen of ASV21, which was viewed in a radar 'tent' on board the aircraft.
579:
of the Argus Mark I's. The Argus was widely described as the best anti-submarine aircraft of its era. ASV21D also equipped the
509:
443:, which had previously used the early Mark II radars, the Mark X was further adapted as the Mark XI. This used a new narrow
399:
368:
360:
587:
in the Nimrod MR 2 starting in 1980. ASV 21 remained in service on the Argus until the last example retired in 1981.
770:
ASV Mark X - RAF name for US ASD-1/APS-15 X-band system; used primarily on Liberators; not to be confused with ASVX
143:
736:
ASV Mark VIA - added lock-follow which could direct the Leigh light, a separate pilot indicator, and blind-bombing
628:
Radar returned to the nose in the Nimrod, with this MR2 showing no outward sign of the Searchwater radar within.
241:
1521:
697:
Mark IIIB - Mk. IIIA with internal modifications allowing the same unit to be used by Coastal or Bomber command
340:
788:
ASV Mark XIII - modified Mk. XI for Mosquito, Beaufighter and Brigand; did not enter service before war ended
643:
aircraft. A new version of Searchwater, the LAST, was created to provide this coverage when mounted under a
185:
later commented that "This, had they known, was the writing on the wall for the German Submarine Service."
640:
580:
306:
803:
ASV Mark XV - miniaturized version of XI; did not enter service but acted as the basis for future designs
572:
468:
459:
rockets with armor-piercing warheads to damage or puncture the U-boat making it impossible to dive, and
513:
The Shackleton MR2 moved its Mark 13 radar to the ventral position in a well-streamlined installation.
315:
275:
230:
178:
162:
147:
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miles south of them. Shipping also appeared, but the team was unable to test this very well as their
77:
50:
624:
778:
ASV Mark XI - originally known as ASVX, X-band design for Barracuda but used primarily on Swordfish
655:
637:
472:
287:
747:
388:
249:
56:
The first ASV was developed after the accidental detection of wharves and cranes while testing an
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92:
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in the summer of 1942, but they predicted it would not be widely available until summer 1943.
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at night, but the target had to be seen to be attacked, a problem that was addressed with the
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364:
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65:, replaced it at the end of the year, but the system was not widespread until late in 1941.
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816:
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545:
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46:
38:
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it could be used against U-boats. It was not until late 1943 that a naval version of the
758:
ASV Mark VIII - RAF name for US AN/APS-3 radars; used mainly on Catalinas from June 1944
1166:
807:
750:- largely similar to Mk. III but operating in the X-band at 3 cm; not widely used
553:
534:
530:
483:
425:
336:
166:
1515:
1494:
Airborne Maritime Surveillance Radar: Volume 2, Post-War British ASV Radars 1946-2000
1130:
Airborne Maritime Surveillance Radar: Volume 2, Post-War British ASV Radars 1946-2000
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495:
384:
332:
319:
222:
1473:
Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
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Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
999:
Airborne Maritime Surveillance Radar: Volume 1, British ASV Radars in WWII 1939-1945
17:
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464:
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294:
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suggested a new ASV could be quickly introduced by making minor changes to the new
258:
85:
42:
229:
The Germans ultimately solved the problem of Mark II with the introduction of the
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1471:
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1401:
1354:
761:
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433:
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202:
197:
The antenna array of the Mark II was quite large and produced considerable drag.
104:
73:
62:
124:
719:
671:
491:
174:
158:
128:
1455:
1323:
1229:
1159:
812:
ASV Mark 19A - made by Echo for the Royal Navy Gannet and Sea Prince aircraft
683:
ASV Mark IIA - Mk. II with more powerful 100 kW transmitter; 12 produced
599:
Seaspray on the Lynx was an export success, seen here in the Royal Thai Navy.
387:
at 1.25 cm. The UK-developed 3 cm version for the Liberator became
733:- high-power Mk. III with 200 kW magnetron, "Vixen", and stabilization
651:
576:
429:
279:
268:
139:
81:
53:
classification, which includes similar radars in ground and ship mountings.
544:
A more suitable custom-built patrol aircraft was a priority and led to the
722:- RAF name for US APG (AN/APS-2) radars used on Liberators and Fortresses
765:
713:
613:
522:
57:
1182:
McLelland, Tim (ed.), "Avro Shackleton, the RAF's Cold War Sub Hunter",
452:
691:- centimetric radar based on H2S; widely used from March 1943 onwards
463:
to mark the location for follow-up attacks by other aircraft carrying
403:
The Swordfish mounted the ASV Mark XI radome between its landing gear.
815:
ASV Mark 21 - new design by EMI used on Canadair CP-107 Argus Mk II,
444:
380:
349:
69:
537:
had become passé by this point, and these units were referred to as
467:. Further developments of this system led to the Mark XIII, used on
91:
In the post-war era, several new ASV radars were developed, notably
623:
594:
508:
460:
398:
353:
248:
240:
192:
142:. They eventually realized these were the docks and cranes at the
123:
310:
problem but also allowed Mark II to once again become effective.
305:
Instead, their aircraft were using a receiver tuned to the Metox
274:
It was at this point that the Metox started to become effective.
456:
806:
ASV Mark XVI - RAF name for US LHTR, a range-only unit used by
533:
bombers with Mark VII to become the Lancaster GR.3. The use of
482:
The Beaufighter, which became one of Coastal Command's primary
282:, mostly to the antenna. This started a furious debate between
1376:"H2S Radar in Bomber Command and ASV Radar in Coastal Command"
564:
1186:, no. Icons No 21, Key Publishing Ltd, pp. 20, 33,
1336:
1091:
1079:
1023:
856:
583:
when it came into service in 1970, and was replaced by the
318:
arrived, having originally been developed to allow German
161:
that were able to fly out over the North Sea from nearby
134:
demonstrated ASV in commanding fashion in September 1937.
1383:
Canadians on Radar: Royal Canadian Air Force 1940 - 1945
965:
963:
961:
694:
Mark IIIA - improved version available from late 1943
1241:
1239:
822:
ASV Mark 21D - modified version fitted to Nimrod MR1
753:
ASV Mark 7A - post-war version used on Lancaster GRs
612:. This was originally developed in concert with the
1208:
1206:
1204:
1202:
716:; largely withdrawn by late 1943 in favour of Mk. V
356:, the ASG, which was much better than the SCR-517.
674:- 1.5 m VHF, 300 prototype sets built in 1940
455:impossible, so these aircraft were fit with eight
680:- production version of Mark I; ~23,000 produced
739:ASV Mark VIB - production version of the Mk. VIA
1036:
1034:
1032:
992:
990:
742:ASV Mark VIC - version of Mk. VI for Sunderland
451:. The radome's location made the carriage of a
1252:The Shackleton Association (thegrowler.org.uk)
552:. The main improvements were the addition of
286:, who wanted every H2S for their bombers, and
608:, a small unit designed to be mounted on the
45:and they have remained a major instrument on
8:
348:SCR-517 into production instead. Meanwhile,
1277:
1275:
1273:
1271:
1269:
1267:
1248:"Ballykelly – The Shackleton Era 1952-1971"
293:After several changes in policy, the first
37:for short, is a classification used by the
1316:Royal Air Force Historical Society Journal
1288:Defence Electronics History Society (DEHS)
1222:Royal Air Force Historical Society Journal
1215:"Maritime Patrol in the Piston Engine Era"
1177:
1175:
1152:Royal Air Force Historical Society Journal
1145:"Maritime Patrol in the Piston Engine Era"
383:at 3 cm wavelength, and later in the
363:, which had the range to operate over the
290:, who wanted them for submarine hunting.
49:since that time. It is part of the wider
952:
791:ASV Mark 13A - post-war version used on
773:ASV Mark XA - APS-5A, minor improvements
548:. The Shackleton Mk 1 and 2 mounted the
837:
1067:
1055:
1011:
981:
969:
940:
928:
916:
904:
892:
764:- RAF name for US ASH, later known as
1527:Military radars of the United Kingdom
1424:Echoes of War: The Story of H2S Radar
1115:
1103:
880:
868:
844:
819:, and retrofitted to Shackleton Mk 2,
339:, and local development began at the
80:. The RAF responded by deploying the
7:
616:missile to allow the Lynx to attack
1284:"2018 Russell Burns Spring Lecture"
541:, remaining in service until 1954.
529:by adapting surplus Bomber Command
725:ASV Mark VA - improved ASG.3/APS-2
331:The magnetron was revealed to the
25:
447:that fit between the Swordfish's
352:had been developing a system for
165:. The testing was crude; a small
150:was forbidden to fly over water.
785:for Beaufighter strike fighters
1:
1353:Bowen, Edward George (1998).
432:even if they did not carry a
153:To further test the concept,
68:ASV was useful for detecting
1491:Watts, Simon (August 2018).
1470:Watts, Simon (August 2018).
31:Radar, Air to Surface Vessel
1381:. In Grande, George (ed.).
1282:Bruton, Liz (6 July 2018),
581:Hawker Siddeley Nimrod MR 1
428:system, as it could detect
369:Boeing B-17 Flying Fortress
361:Consolidated B-24 Liberator
157:provided the team with two
1543:
256:
200:
1497:. Morgan & Claypool.
1476:. Morgan & Claypool.
575:, replacing the American
567:developed a replacement,
1456:10.1049/ip-a-1.1985.0071
1421:Lovell, Bernard (1991).
781:ASV Mark XII - modified
700:Mark IIIC - Mk. III for
439:In order to upgrade the
341:MIT Radiation Laboratory
263:The introduction of the
27:RAF radar classification
1374:Campbell, W.P. (2000).
632:Another example is the
327:Other WWII developments
1184:Aeroplance Illustrated
800:ASV Mark XIV - unknown
712:- RAF name for the US
667:From Watts and Smith:
641:airborne early warning
629:
600:
514:
469:de Havilland Mosquitos
404:
307:intermediate frequency
254:
246:
198:
135:
1307:Coleman, Ian (2005).
1165:This says that "some
1106:, pp. 22–23, 35.
795:, and Shackleton Mk 2
650:ASV13 and ASV21 used
627:
598:
573:Canadair CP-107 Argus
512:
505:Post-war developments
402:
395:Late-war developments
252:
244:
196:
127:
1400:Gough, Jack (1993).
1213:Tyack, Bill (2005).
1143:Tyack, Bill (2005).
473:Bristol Beaufighters
316:Naxos radar detector
276:Robert Hanbury Brown
231:Metox radar detector
179:Albert Percival Rowe
163:RAF Martlesham Heath
148:Handley Page Heyford
78:Metox radar detector
51:surface-search radar
18:Air-Sea Vessel radar
1132:. pp. 2-1–2-7.
984:, pp. 165–167.
638:Fairey Gannet AEW.3
569:ASV Mark 21 (ASV21)
550:ASV Mark 13 (ASV13)
517:With the ending of
335:in 1940 during the
288:RAF Coastal Command
1224:(33): 73, 75, 80.
955:, p. XVII-10.
704:using two scanners
630:
601:
591:Later developments
515:
405:
284:RAF Bomber Command
255:
247:
199:
155:Robert Watson-Watt
136:
1444:IEE Proceedings A
1413:978-0-11-772723-6
1337:Smith et al. 1985
1193:978-1-910415-22-1
1092:Smith et al. 1985
1080:Smith et al. 1985
1024:Smith et al. 1985
857:Smith et al. 1985
783:AI Mk. VIII radar
645:Westland Sea King
618:fast attack craft
585:Searchwater radar
115:WWII developments
16:(Redirected from
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817:Shackleton Mk 3
808:strike fighters
793:Shackleton Mk 1
665:
656:TWT transmitter
593:
546:Avro Shackleton
507:
484:strike fighters
397:
329:
299:strike aircraft
261:
239:
205:
191:
122:
120:Initial concept
117:
47:patrol aircraft
39:Royal Air Force
28:
23:
22:
15:
12:
11:
5:
1540:
1538:
1530:
1529:
1524:
1514:
1513:
1510:
1509:
1503:
1488:
1482:
1465:
1462:
1461:
1460:
1450:(6): 359–384.
1439:
1433:
1418:
1412:
1397:
1391:
1371:
1365:
1348:
1345:
1342:
1341:
1329:
1299:
1263:
1235:
1198:
1192:
1171:
1135:
1128:Watts (2018).
1120:
1108:
1096:
1094:, p. 384.
1084:
1082:, p. 377.
1072:
1070:, p. 247.
1060:
1058:, p. 246.
1048:
1045:. p. 8-3.
1041:Watts (2018).
1028:
1026:, p. 371.
1016:
1014:, p. 166.
1004:
1001:. p. 8-2.
997:Watts (2018).
986:
974:
972:, p. 165.
957:
945:
943:, p. 163.
933:
931:, p. 159.
921:
919:, p. 158.
909:
907:, p. 157.
897:
895:, p. 156.
885:
883:, p. 209.
873:
861:
859:, p. 360.
849:
836:
835:
833:
830:
828:
825:
824:
823:
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707:
706:
705:
698:
695:
686:
685:
684:
675:
664:
661:
592:
589:
535:Roman numerals
531:Avro Lancaster
506:
503:
426:air-sea rescue
396:
393:
337:Tizard Mission
328:
325:
320:night fighters
257:Main article:
238:
235:
201:Main article:
190:
187:
167:dipole antenna
121:
118:
116:
113:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1539:
1528:
1525:
1523:
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1506:
1504:9781643270692
1500:
1496:
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1483:9781643270661
1479:
1475:
1474:
1468:
1467:
1463:
1457:
1453:
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1445:
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1436:
1434:9780852743171
1430:
1427:. CRC Press.
1426:
1425:
1419:
1415:
1409:
1405:
1404:
1398:
1394:
1392:9780968759608
1388:
1384:
1377:
1372:
1368:
1366:9780750305860
1362:
1359:. CRC Press.
1358:
1357:
1351:
1350:
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1338:
1333:
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1325:
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1317:
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1303:
1300:
1289:
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1278:
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1274:
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1268:
1264:
1253:
1249:
1246:Hill, David,
1242:
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1223:
1216:
1209:
1207:
1205:
1203:
1199:
1195:
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1153:
1146:
1139:
1136:
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1124:
1121:
1118:, p. 43.
1117:
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1100:
1097:
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1076:
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1017:
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1005:
1000:
993:
991:
987:
983:
978:
975:
971:
966:
964:
962:
958:
954:
953:Campbell 2000
949:
946:
942:
937:
934:
930:
925:
922:
918:
913:
910:
906:
901:
898:
894:
889:
886:
882:
877:
874:
871:, p. 45.
870:
865:
862:
858:
853:
850:
847:, p. 38.
846:
841:
838:
831:
826:
821:
818:
814:
811:
809:
805:
802:
799:
794:
790:
789:
787:
784:
780:
777:
772:
771:
769:
767:
763:
760:
757:
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751:
749:
746:
741:
738:
735:
734:
732:
729:
724:
723:
721:
718:
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711:
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703:
699:
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693:
692:
690:
687:
682:
681:
679:
676:
673:
670:
669:
668:
662:
660:
657:
653:
648:
646:
642:
639:
635:
626:
622:
619:
615:
611:
610:Westland Lynx
607:
597:
590:
588:
586:
582:
578:
574:
570:
566:
562:
560:
555:
554:stabilization
551:
547:
542:
540:
536:
532:
526:
524:
520:
511:
504:
502:
500:
497:
496:Fleet Air Arm
493:
489:
485:
480:
478:
474:
470:
466:
465:depth charges
462:
458:
454:
450:
446:
442:
437:
435:
431:
427:
423:
418:
416:
412:
411:
401:
394:
392:
390:
386:
382:
377:
373:
370:
366:
362:
357:
355:
351:
347:
342:
338:
334:
333:United States
326:
324:
321:
317:
311:
308:
302:
300:
296:
291:
289:
285:
281:
277:
272:
270:
266:
260:
251:
243:
236:
234:
232:
227:
224:
223:Bay of Biscay
219:
215:
209:
204:
195:
189:Mark I and II
188:
186:
184:
180:
176:
171:
168:
164:
160:
156:
151:
149:
145:
144:Harwich docks
141:
133:
130:
126:
119:
114:
112:
110:
106:
102:
98:
94:
89:
87:
83:
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48:
44:
40:
36:
32:
19:
1493:
1472:
1447:
1443:
1423:
1402:
1382:
1355:
1347:Bibliography
1332:
1315:
1302:
1291:, retrieved
1287:
1255:, retrieved
1251:
1221:
1183:
1151:
1138:
1129:
1123:
1111:
1099:
1087:
1075:
1063:
1051:
1042:
1019:
1007:
998:
977:
948:
936:
924:
912:
900:
888:
876:
864:
852:
840:
748:ASV Mark VII
689:ASV Mark III
666:
649:
631:
602:
563:
543:
527:
519:World War II
516:
481:
449:landing gear
438:
421:
419:
414:
409:
406:
389:ASV Mark VII
378:
374:
358:
330:
312:
303:
295:ASV Mark III
292:
273:
262:
259:ASV Mark III
228:
210:
206:
172:
152:
137:
131:
90:
86:ASV Mark III
67:
55:
43:World War II
34:
30:
29:
1068:Lovell 1991
1056:Lovell 1991
1012:Lovell 1991
982:Lovell 1991
970:Lovell 1991
941:Lovell 1991
929:Lovell 1991
917:Lovell 1991
905:Lovell 1991
893:Lovell 1991
762:ASV Mark IX
731:ASV Mark VI
710:ASV Mark IV
678:ASV Mark II
663:System list
634:Searchwater
559:Sea State 1
539:ASV Mark 7A
434:transponder
218:searchlight
214:Leigh Light
203:ASV Mark II
159:Avro Ansons
105:Searchwater
101:ASV Mark 21
97:ASV Mark 13
93:ASV Mark 7A
84:-frequency
74:Leigh light
63:ASV Mark II
1516:Categories
1356:Radar Days
1318:(33): 93.
1154:(33): 68.
1116:Gough 1993
1104:Gough 1993
881:Bowen 1998
869:Bowen 1998
845:Bowen 1998
827:References
720:ASV Mark V
702:Sunderland
672:ASV Mark I
652:magnetrons
492:lend-lease
430:life rafts
175:Royal Navy
129:Avro Anson
1324:1361-4231
1230:1361-4231
1160:1361-4231
832:Citations
577:AN/APS-20
422:schnorkel
415:schnorkel
410:schnorkel
280:H2S radar
269:Metrovick
140:North Sea
82:microwave
35:ASV radar
1406:. HMSO.
1309:"Nimrod"
1293:5 August
1257:6 August
766:AN/APS-4
714:DMS-1000
614:Sea Skua
606:Seaspray
523:Cold War
499:Avengers
372:Mark V.
237:Mark III
109:Seaspray
453:torpedo
181:of the
70:U-boats
1501:
1480:
1431:
1410:
1389:
1363:
1322:
1228:
1190:
1158:
461:flares
445:radome
385:K-band
381:X-band
354:blimps
350:Philco
1379:(PDF)
1312:(PDF)
1218:(PDF)
1148:(PDF)
132:K8758
33:, or
1499:ISBN
1478:ISBN
1429:ISBN
1408:ISBN
1387:ISBN
1361:ISBN
1320:ISSN
1295:2020
1259:2020
1226:ISSN
1188:ISBN
1156:ISSN
475:and
457:RP-3
216:, a
107:and
99:and
1452:doi
1448:132
565:EMI
488:Gee
1518::
1446:.
1385:.
1314:.
1286:,
1266:^
1250:,
1238:^
1220:.
1201:^
1174:^
1150:.
1031:^
989:^
960:^
501:.
479:.
471:,
436:.
417:.
111:.
95:,
1507:.
1486:.
1458:.
1454::
1437:.
1416:.
1395:.
1369:.
1339:.
1326:.
1232:.
1162:.
557:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
