Radar reflectors

[Giblets]

this could be worth keeping at eye out for.

 

[Topcat47]

When they were dear old DERA, they did one for West Sussex Trading Standards..........I wish I'd kept my copy of that report...

 

[Andrew_Fanner]

IIRC one of the mags did a test <1 year ago

 

[deep denial]

yes, they did, PBO iirc. The most striking conclusion was that the Sea-me active radar target enhancer was streets better than the passive ones

 

[markstirling]

Thats right, except that the sea-me only works on X-band and has no effect at all on S-band, so a combination of passive and active may be the best bet.

 

[Twister_Ken]

Much as I admire the Sea-Me, it does seem to me it could do with some serious competition. Essentially it's a single frequency radio receiver and transmitter, without any of the complexity of a broadband rx/tx set. Yet you could buy 4 handheld VHF broadband tx/rx sets for the price of one Sea-Me. For such a significant piece of safety equipment the price does seem ludicrous. Reckon it's time NASA made one.

 

[johnalison]

I think the argument was that S-band is only used at close-quarters around harbours and not for collision-avoidance at sea.

 

[jrt]

I think that it is the other way round. /forums/images/graemlins/shocked.gif

X band, 9GHz, being the higher frequency can better do the short pulses needed for close work. S band, 3GHz, one third the frequency and hence three times the wavelength, needs longer pulses and therefore is better at long ranges. /forums/images/graemlins/cool.gif

If someone can confirm this I would appreciate it. /forums/images/graemlins/blush.gif

 

[Sixpence]

S band radars operate on a wavelength of 8-15 cm and a frequency of 2-4 GHz. Because of the wavelength and frequency, S band radars are not easily attenuated. This makes them useful for near and far range weather observation. The National Weather Service (NWS) uses S band radars on a wavelength of just over 10 cm. The drawback to this band of radar is that it requires a large antenna dish and a large motor to power it. It is not uncommon for a S band dish to exceed 25 feet in size.

X band radars operate on a wavelength of 2.5-4 cm and a frequency of 8-12 GHz. Because of the smaller wavelength, the X band radar is more sensitive and can detect smaller particles. These radars are used for studies on cloud development because they can detect the tiny water particles and also used to detect light precipitation such as snow. X band radars also attenuate very easily, so they are used for only very short range weather observation. Also, due to the small size of the radar, it can therefore be portable like the Doppler on Wheels. (DOW) Most major airplanes are equipped with an X band radar to pick up turbulence and other weather phenomenon. This band is also shared with some police speed radars and some space radars.

http://www.everythingweather.com/weather-radar/bands.shtml

 

[Duffer]

How do you know if it is still working? Presumably you should use it in addition to a passive reflector.