"Larry W4CSC" wrote in message

Ah, but you have another problem in the fog. The higher the antenna, the
further away the target will disappear as the target approaches the boat!
You won't see the bouy 8 miles away with the antenna down low, but you
WILL
see the bouy in the fog a LOT closer to the boat as you, hopefully, pass
it.

Traveling at Mach 1, I'd understand having more range. But, traveling at
6
knots I'd rather see that target two boatlengths off the port bow with a
lower-down antenna....wouldn't you?

I have to wonder how serious a problem this really is.
For instance, if I can run between two buoys spaced 300' with a scanner
that's over 100' in the air and watch them pass down my side, how much
difference can there be with a small boat and a scanner placed 30' up,
unless you are totally crowding the buoy to one side (not good).
Also, by that point, if you lose sight of the buoy, you should have all
ready changed your concentration to some new point or reference, ahead.

otn

In article . net,
"otnmbrd" wrote:

I have to wonder how serious a problem this really is.
For instance, if I can run between two buoys spaced 300' with a scanner
that's over 100' in the air and watch them pass down my side, how much
difference can there be with a small boat and a scanner placed 30' up,
unless you are totally crowding the buoy to one side (not good).
Also, by that point, if you lose sight of the buoy, you should have all
ready changed your concentration to some new point or reference, ahead.

otn

OTN, the Horozontal Beamwidth of your Commercial Maritime Radar is
significantly smaller than that of the units found on most Pleasure
type vessels. That makes a HUGH difference in the Target Discrimination
Ability between the two radars. Apples and Oranges, here.......


Bruced in alaska
--
add a 2 before @

"Bruce in Alaska" wrote in message news:

OTN, the Horozontal Beamwidth of your Commercial Maritime Radar is
significantly smaller than that of the units found on most Pleasure
type vessels. That makes a HUGH difference in the Target Discrimination
Ability between the two radars. Apples and Oranges, here.......


Bruced in alaska


This I understand. However, and here I need to be careful to note that my
comments are not technical, rather, practical experience based, dating back
to Decca 101's and KH 17's , on multiple size/type vessels ...... I've
rarely experienced a serious problem with close aboard, lost targets that
would negatively impact the navigational procedure I was using, including
docking.
Admittedly, some units were better than others, either due to the basic unit
and/or it's condition and you needed to adjust some procedures, but, my
point is that you don't want to consider a radar's use "drop dead useless"
below a certain range, based on pure technical data, without first checking
your particular unit under real conditions to see if they apply or are
indeed a problem.

MOFWIW

otn

In article et,
"otnmbrd" wrote:

This I understand. However, and here I need to be careful to note that my
comments are not technical, rather, practical experience based, dating back
to Decca 101's and KH 17's , on multiple size/type vessels ...... I've
rarely experienced a serious problem with close aboard, lost targets that
would negatively impact the navigational procedure I was using, including
docking.
Admittedly, some units were better than others, either due to the basic unit
and/or it's condition and you needed to adjust some procedures, but, my
point is that you don't want to consider a radar's use "drop dead useless"
below a certain range, based on pure technical data, without first checking
your particular unit under real conditions to see if they apply or are
indeed a problem.

MOFWIW

otn

Yep, I'll go along with that......


Bruce in alaska
--
add a 2 before @

On Tue, 15 Feb 2005 07:38:34 GMT, "otnmbrd"
wrote:


"Larry W4CSC" wrote in message

Ah, but you have another problem in the fog. The higher the antenna, the
further away the target will disappear as the target approaches the boat!
You won't see the bouy 8 miles away with the antenna down low, but you
WILL
see the bouy in the fog a LOT closer to the boat as you, hopefully, pass
it.

Traveling at Mach 1, I'd understand having more range. But, traveling at
6
knots I'd rather see that target two boatlengths off the port bow with a
lower-down antenna....wouldn't you?

I have to wonder how serious a problem this really is.
For instance, if I can run between two buoys spaced 300' with a scanner
that's over 100' in the air and watch them pass down my side, how much
difference can there be with a small boat and a scanner placed 30' up,
unless you are totally crowding the buoy to one side (not good).
Also, by that point, if you lose sight of the buoy, you should have all
ready changed your concentration to some new point or reference, ahead.

It is a big problem with small-craft radars, in my experience. The
vertical angle is nothing like what you describe on the Furuno and
Raytheon units I have used.
Rodney Myrvaagnes Opionated old geezer

Faith-based economics: It's deja voodoo all over again