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Matt O'Toole Matt O'Toole is offline
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First recorded activity by BoatBanter: Sep 2006
Posts: 106
Default Raster vs Vector (Was Electronic Charting)

On Mon, 18 Sep 2006 07:45:00 -0400, Gerald wrote:

"Matt O'Toole" wrote in message
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I haven't tried Fugawi, but I'd like to. I'm convinced vector charts
are the way to go.


And I am convinced that raster charts are the way to go and that,
perhaps, I am not in the mainstream and have made it to the position of
'old-fart'. I am in the process of looking at some current generation
chart plotters to go on a new boat. I haven't paid much attention to
marine electronics in the past 6 or 7 years since I outfitted my last
boat. It has surprised my that every non-pc based chart plotter out
there is vector based --- no one has done one to support raster.


This is because raster charts take too much processing power and memory
for simple, low-power devices like handheld plotters. Vector charts also
render much faster on all devices, for instant loading, zooming and
panning.

I have been using paper charts for nearly 55 years. My last 2 boats had
PC based systems (Maptech and/or Cap'n). I found that having chart
images on my screen that looked exactly like the charts on my nav table
was a BIG plus.


There's nothing wrong with a personal preference. A lot of people
prefer traditional charts.

One thing I like about paper/raster charts is that you know when you've
reached their limit of resolution, because the picture gets grainy.
Vector charts can be too smooth at their limit. They're supposed to have
a warning label to tell you when you've zoomed in too far, but I think the
grainy picture is more intuitive.

BTW, I usually have a paper chart open too, along with my electronic one.

It has been my experience that vector charts have less information on
them than raster charts. While some see this as an advantage I do not:
one mans clutter is another mans important data. Most of the vector
charts that I have looked at do not show light characteristics: you
need to point to it to get a pop up. That makes absolutely no sense to
me. Having to manage my vessel and putz around with a pointing device
trying to find the light with a 6 second flash is somewhere between dumb
and dangerous. Raster charts have all the information right there with
no screwing around. Vector technology salesmen take great pride in
their products' ability to remove layers of information to 'unclutter'
the screen. When they demo this feature, all I see being removed is
information I deem important.


This is all a function of the plotter software, not vector charts
themselves. Vector charts are basically a database, which can hold many
more layers of information than raster charts. Which information gets
shown is decided by the software designer, and then the user. But as
you've found, software designers often make poor choices!

My understanding of the vector chart
manufacturing process is that they all start out with the raster charts.
So they do not have any more accurate or timely information. In fact
the process of going from one format to the other has been known to
introduce errors.


Actually it's the other way around. The new master format is a database,
which can be updated in whole or in part, have layers added, etc. -- like
GIS for the sea. Charts can be rendered from this in vector or raster
formats.

Let me say at this point that I am a retired geek. I have spent most of
my life playing around with the then current technologies. I still
consider my self to be pretty much of a geek. So I am not afraid of
something new. I had great hope for vector charting. but IMHO, that
promise has yet to be fulfilled. The biggest failure of this technology
is in not being able to provide timely updates. With digital, it should
be a simple matter to push out weekly (daily ??) NTM updates via the
internet. This is something I had been able to do with the MapTech Pro
service . Each week I would get NTM updates to 100% of my charts. Now,
you can download them yourself for free. Not with vector charts.


Actually the technology allows much easier updating. Whether they're
doing it or not is another story, but apparently they are. Some info:

http://www.nauticalcharts.com/fugawi-c.htm

So, less information, less accurate information, less usable
information, what am I missing? Am I really getting that far out of
touch?


Not really. I don't think the promise has been realized either, but
that's the fault of the software marketers, not vector charting itself.

Matt O.