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Subject: TWL: LCD and Gray Scales
From: Michael Maurice (mikem@XXX.XXX)
Date: Mon Apr 02 2001 - 06:44:59 EDT
Georgs, Post this to TWL will you. I'll be away for a while on a delivery
from San Diego to Seattle.
I have been having a think about LCD and gray levels.
It seems that I missed a whole bunch of new LCD radars in the Consumer
Marine Electronics Cataloge. There are couple of pages of High End radars
with LCD ($4000+). This is new stuff this year, I gather. But I noticed
that some of them still say, 4 levels of gray.
Someone made the remark that looking at the difference of 4 levels or 8
levels was like trying to discern tea leaves or some such.
And I have thought about that. So here is it is.
It's NOT that the eye can discern all that well 4 or 8 levels, but the
display machinery in the radar can! I don't claim to be able to discern the
difference. But I can adjust the machine to delete levels below say 3 and
on a 4 level machine, that only leaves the brightest level.
But on an 8 level machine that still leaves 5 levels of intensity which is
the power being returned from the target. This allows you to get rid of the
low power reflections from birds, whitecaps and other "clutter" and still
have targets of importance. Like small boats.
Mike
Capt. Mike Maurice
Near Portland Oregon.
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