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Page history last edited by Alan Hartley-Smith 1 year, 6 months ago



The post-war use of radar in civil applications after the Second World War from 1945 followed on from the similar extensive wireless systems deployed for the early air traffic control purposes following the First World War from 1919 details of which are recorded in the Marconi In Avionics wiki.  


Civil Radar Sensors



This covers the radars introduced for the new post-war market in marine navigation and civil aviation.



Designed for the Marconi Marine Company


3cm ATC Radar (1952)

 A by-product of Radiolocator II was the Airfield Control Radar sold to Jersey. This used an early fluoride display tube and had DF bearings superimposed.. The TX used a hydrogen thyratron instead of a spark gap and a much higher powered magnetron, the RX was both log and linear and the back to back antenna, high and low looking was new and fitted with removable circular polariser gates. The vertical linear feed was designed by John Rodgers. Unfortunately his first designs had the beam pointing at the ground; he forgot that the beam was formed towards the load! (A  copy of a picture of Baddow in 1947 or 48 showing the antenna on the roof is at Sandford Mill).

The installation at Jersey is the subject of an article in Marconi Companies and Their People magazine October 1952.


Type S232

The S232 was one of the first ATC radars operating in the 50cm band and was developed in 1954. It incorporated a fully coherent Moving Target Indicator (MTI) and the prototype was first installed at London Heathrow airport - further discussed in Marconi Companies and their People for May 1955 - including mention of the Type 13 Heightfinder used for civil aviation. The transmitter was derived from that used on the Type 11 radar and had a peak power of  50Kw. The 50cm frequency provided very good performance in precipitation conditions (unlike 10cm) and was one of the reasons it became so popular in the 50/60's. Signals were passed to the operations site where they were processed by the MTI equipment.  Water delay lines were used for the MTI signal processing.


The antenna was usually mounted at ground level (to preserve the coverage pattern) and the electronics installed underneath in a "bunker".



Type S264 series


Prototype S264 Antenna installed at Rivenhall (Picture, R.A. Webb)






Type S654

L band long range



Type S511

S band airfield surveillance



Type S512

This was a variant of the S511 using a driven (TWT) as opposed to a magnetron transmitter.




Plot Assignor



"PEST" Vehicle Equipment



Mode-S and RDPDS Interface Study



SECAR Secondary Surveillance Radar



Messenger Secondary Surveillance Radar



Challenger Secondary Surveillance Radar 

announcement at Farnborough Airshow


Later Systems









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Ian Gillis said

at 5:57 pm on Feb 10, 2016

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