In an attempt to discuss something related to cruising, can someone explain
the differences between X-band and S-band radar systems? From what I know,
S-band is used on large ships and X-band is used on vessels less than 300
tons.

-- Geoff
www.GeoffSchultz.org

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone explain
the differences between X-band and S-band radar systems? From what I know,
S-band is used on large ships and X-band is used on vessels less than 300
tons.


The dimensions of an antenna array of given geometry/gain/beamwidth
etc. are scaled according to wavelength. Big wavelength, big anttenna,
big boat. Next..

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone explain
the differences between X-band and S-band radar systems? From what I know,
S-band is used on large ships and X-band is used on vessels less than 300
tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Wayne.B wrote in
:

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone
explain the differences between X-band and S-band radar systems? From
what I know, S-band is used on large ships and X-band is used on
vessels less than 300 tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Wayne,

Thanks for actually answering the question instead of providing a smart-ass
answer that didn't provide any useful information.

-- Geoff
www.GeoffSchultz.org

On Tue, 06 Jan 2009 12:51:28 -0600, Geoff Schultz
wrote:

Wayne.B wrote in
:

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone
explain the differences between X-band and S-band radar systems? From
what I know, S-band is used on large ships and X-band is used on
vessels less than 300 tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Wayne,

Thanks for actually answering the question instead of providing a smart-ass
answer that didn't provide any useful information.

-- Geoff
www.GeoffSchultz.org

If you can judge the accuracy of the answer then you have no need to
ask the question. Angular resolution is determined by the horizontal
beamwidth and range resolution by (effective) pulse width, not
wavelength. as such.

In article ,
Wayne.B wrote:

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone explain
the differences between X-band and S-band radar systems? From what I know,
S-band is used on large ships and X-band is used on vessels less than 300
tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Add to the above, that Marine S-Band Radars are 2.9 - 3.2 Ghz and Marine
X-Band Radar are 9.3 - 9.5 Ghz. S-Band Radars are much more likely to be
blinded by Snow and Heavy Rain that X-Band Radars. S-Band Radars require
Antennas that are MUCH Larger than X-Band Radars due to the Frequencies
involved. S-Band Radars predate X-Band Radars in production because
Magnetrons were easier to build, for the Lower Frequencies. Most Marine
WWII Radars were S-Band, including the venerable SO Radar fitted to the
PT Boats, who's antenna looks like an upside down R2D2 on a Mast.

--
Bruce in alaska
add path after fast to reply

"Geoff Schultz" wrote in message
.. .
Wayne.B wrote in
:

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone
explain the differences between X-band and S-band radar systems? From
what I know, S-band is used on large ships and X-band is used on
vessels less than 300 tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Wayne,

Thanks for actually answering the question instead of providing a
smart-ass
answer that didn't provide any useful information.

-- Geoff
www.GeoffSchultz.org

Please allow me to correct this shortcoming:

The difference is that one is spelled with an "X"...

Bruce,
Perhaps I am confused, but I have been taught that the larger wavelength
radar (S-Band) is not affected by weather as much as X-Band. It will
penetrate weather and resolve targets behind the weather better than X-Band.
Where X-Band radars are better at displaying the weather itself. I have also
been told that S-Band discriminates ice from sea clutter better than X-Band.
Steve


"Bruce in alaska" wrote in message
...
In article ,
Wayne.B wrote:

On Tue, 06 Jan 2009 11:23:34 -0600, Geoff Schultz
wrote:

In an attempt to discuss something related to cruising, can someone
explain
the differences between X-band and S-band radar systems? From what I
know,
S-band is used on large ships and X-band is used on vessels less than
300
tons.

-- Geoff
www.GeoffSchultz.org

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased signal
attenuation. S band typically has greater range but requires much
larger antennas, too large for the average small to mid size pleasure
boat.

Add to the above, that Marine S-Band Radars are 2.9 - 3.2 Ghz and Marine
X-Band Radar are 9.3 - 9.5 Ghz. S-Band Radars are much more likely to be
blinded by Snow and Heavy Rain that X-Band Radars. S-Band Radars require
Antennas that are MUCH Larger than X-Band Radars due to the Frequencies
involved. S-Band Radars predate X-Band Radars in production because
Magnetrons were easier to build, for the Lower Frequencies. Most Marine
WWII Radars were S-Band, including the venerable SO Radar fitted to the
PT Boats, who's antenna looks like an upside down R2D2 on a Mast.

--
Bruce in alaska
add path after fast to reply

On Tue, 06 Jan 2009 20:08:44 GMT, Bruce in alaska
wrote:
S-Band Radars are much more likely to be
blinded by Snow and Heavy Rain that X-Band Radars.

..or vica versa..
http://www.cosis.net/abstracts/ERAD0...-A-00131-1.pdf

Bruce in alaska wrote in
:

In article ,
Wayne.B wrote:

The key difference is that they operate in two completely different
frequency ranges, much like the difference between VHF and UHF
television. X-band is from is from 7 to 12.5 GHz, S-band is at a
lower frequency (longer wavelength) between 2 and 4 GHz.

Because of the shorter wavelength, X band radar can resolve between
smaller objects but usually has less range because of increased
signal attenuation. S band typically has greater range but requires
much larger antennas, too large for the average small to mid size
pleasure boat.

Add to the above, that Marine S-Band Radars are 2.9 - 3.2 Ghz and
Marine X-Band Radar are 9.3 - 9.5 Ghz. S-Band Radars are much more
likely to be blinded by Snow and Heavy Rain that X-Band Radars. S-Band
Radars require Antennas that are MUCH Larger than X-Band Radars due to
the Frequencies involved. S-Band Radars predate X-Band Radars in
production because Magnetrons were easier to build, for the Lower
Frequencies. Most Marine WWII Radars were S-Band, including the
venerable SO Radar fitted to the PT Boats, who's antenna looks like an
upside down R2D2 on a Mast.

So am I correct in stating that the S-band radar is typically used for long
distance and X-band for shorter distance? Is it also valid to assume that
if a ship has S-band that it will also have X-band?

-- Geoff
www.GeoffSchultz.org