An interesting explanation, but this isn't the image I see. They appear from
medium sized vessels (tugs, CG, etc). They are roughly a 90 degree arc of a
circle centered on my vessel, and intersecting the target. Thus, the radius
indicates range, and the position of the arc is the approximate direction.
Although I always assumed it was something "active" on the target, I'm beginning
to think it might be entirely my radar. The fact that the arc is on both sides
of the target makes me think that my transmitter is radiating small side lobes
(if that's the correct term) that precede and follow the main beam. If the
target is a large reflector, and my gain is high, that might show as the arc.

-jeff


"Me" wrote in message
...
In article ,
wrote:

On Mon, 01 Dec 2003 19:17:04 GMT, Me wrote:

Again bull****! Would be nice if you knew anything about what your
talking about.

That's why, my little trollsmeg, I said "my understanding". Perhaps
you would enjoy taking the lid off that planet-sized intellect to
share your god-like insights with this NG?

Or just shut the **** up.

R.


There isn't a "Commercial Radar" marketed in the USA that has anywhere
near enough Beam Energy Density to cook even your eyeballs, let alone
any other body parts of any mammal, while in operation, in a standard
installation. One is very much more likely to be hurt by the antenna
hitting them in the head, as it rotates than by the RF coming out of
the antenna. This has been well documented over the last 30 years, and
as the power of these radars has dropped due to the better receiver
technology, it is more true now than 30 years ago.

Next, The dashed arc's one sees displayed on radar screens are other
radars that have transmitting frequencies CLOSE to the receive frequency
of your radar. There is a wide range of frequencies that Xband radars
can and do use and the reciver bandwidth is much narrower than the
transmitter frequency range by 20X or so. Transmit frequencies are
determined by the physical properties of the Magnitron of each radar and
are fixed at the MFG, but do move around due to temp, age, ect. This
means that some show up on your screen and some don't. There are three
different bands that Maritime Radars use Sband, Xband, and KaBand. Of
the three Xband is by far the most cxommon. (Orders of Magnitude more)
Sband is only found on VERY BIG VESSELS, and Kaband is used mainly for
Wx search and is extremly rare aboard any vessels except Research
Vessels. None of the radars will cause interference except in their own
Band Class. The Arc's always show from the center of your display, and
don't have any range or direction information associated with them,
other than they TEND to not be there when you antenna isn't pointed
toward the other radar. Targets that have Dashes the trail the target
on your display are a differet thing altogether. They are Active Radar
Transponders, (Racon's) and are used as Position Identification devices.
These are put on significant Navigation Points and are also used for SAR
Activites and ARE required on Lifeboats of SOLAS Required Ships. Almost
all of these a Xband devices. I have seen one or two Sband
installations, but never any Kaband.

Now that your understanding has been expanded, ...... well ok...we'll
just let it go at that........


me