Joe wrote:


Sometimes a ghost is a reflection that you and nav describe, sometimes
it is an object that is so low or has such a lousy return that it only
shows up when you and the target or on the crest of waves or when the
target is ata angle to reflect your signal. So it may indeed be a real
target but when it keeps disappearing and returning from the scope it
is called a ghost.

Prime example of "One man's ghost" is another man's intermittent target.
I wouldn't call any of you wrong, once I understood what your
description was, though your above does not fall into MY description of
"ghost" even though I can see where it might from your perspective.


otn

Joe wrote:

If you see a ghost on radar are you seeing boobsie?

If not what are you seeing, and how would you define a ghost?


It is a "false" radar return due to the return path delay to the most
recent pulse not being c/d where c is the local speed of light and d
distance to the apparent target. This can arise from anything which
alters propagation and therefore the effective c between transmitter and
reflector. Ghost images have sometimes been incorrectly ascribed to
birds and rain but in fact these are usually real returns and not ghosts.

Cheers

A ghost image is a false image moving in parallel
of a real object being tracked. They tend to be
more of an arc shape or fuzzy in shape compared
to the sharper image or a real object.

They are formed by the signal taking a longer
path to the object. Most commonly from a reflection
off some other part of a larger vessel. This could
change the beam shape of the radar. Sometimes
you can get echos off thunderstorms.

Or perhaps your optical coupler has shorted out. grin


Joe wrote

If you see a ghost on radar are you seeing boobsie?

If not what are you seeing, and how would you define a ghost?

Good for 1.5 asa points

Joe

"Bart Senior" wrote in message . net...
A ghost image is a false image moving in parallel
of a real object being tracked. They tend to be
more of an arc shape or fuzzy in shape compared
to the sharper image or a real object.

They are formed by the signal taking a longer
path to the object. Most commonly from a reflection
off some other part of a larger vessel. This could
change the beam shape of the radar. Sometimes
you can get echos off thunderstorms.

Or perhaps your optical coupler has shorted out. grin

Sorry Bart,

You have over complicated and generalized a ghost. You are partly
correct but.....not completly correct.

Joe





Joe wrote

If you see a ghost on radar are you seeing boobsie?

If not what are you seeing, and how would you define a ghost?

Good for 1.5 asa points

Joe

Bart Senior wrote

Source for next bit was Dutton's.

A ghost image is a false image moving in parallel
of a real object being tracked. They tend to be
more of an arc shape or fuzzy in shape compared
to the sharper image or a real object.

My interpretation based on my radar training.

They are formed by the signal taking a longer
path to the object. Most commonly from a reflection
off some other part of a larger vessel. This could
change the beam shape of the radar. Sometimes
you can get echos off thunderstorms.

This next bit was a joke. An optical coupler can't be shorted out
because it's is a card with holes cut in and and blocks
or passes light to a sensor.

Or perhaps your optical coupler has shorted out. grin

Joe wrote

If you see a ghost on radar are you seeing boobsie?

If not what are you seeing, and how would you define a ghost?