| Jack Erbes 2007-04-30, 10:33 pm |
| MajBach wrote:
<snip>
> uploaded them into the unit. There was one particular spot I was
> anxious to look at, specifically CA 273097. Well that's what the map
> is called when you hover the mouse over it on MapSource, but when you
> select it, it is called CA2202 (E) 20000 in the left column. I
> actually selected many maps of that region when I uploaded them.
CA273097 is a large scale (1:100,000) chart of the Georgian Bay area.
You can see the limits of that map by choosing the Select tool and
moving your cursor over the light blue (unselected) or pink (selected)
boundary lines.
The CA2202(E) is one of the 1:20,000 scale charts included within the
area of the CA273097. There are many charts of various scales in the
area of CA273097.
When you are using the Select tool, the right end of the status line at
the bottom of the MapSource window shows what chart your cursor is over.
There will always be some changes as you move your cursor around and
also as you zoom in and out.
> However, when I viewed them on the GPS, the northern area of the above
> map appeared fine - displaying all the detail like it was displayed on
> the PC. However, when I zoomed in with the cursor placed within that
> map, the display information changed-most of the detail was lost and
> the background went from white to blue. But this was only for the
> northernmost tip of that map, 95% of the map still was normal. What
> struck me as odd was the fact that the detail IS there as I could
> briefly see it as I scrolled the map or zoomed in on an adjacent one,
> but as soon as I got close, it went funky. When I zoom back out, that
> particular area remains blue, unlike it appeared before I zoomed in.
> Thinking it might have something to do with other maps, setting etc, I
> removed all POIs, waypoints and other maps so that only that one map
> was in the unit-no change. At no point does it look like this on the
> computer. the bottom line is, I cannot see the detail in this small
> region of the map - all other areas seem fine, including other map
> areas that overlap. The detail is visible just fine via Mapsourse. Any
> ideas?
The MapSource and BlueChart User's Guides can be downloaded here:
http://www8.garmin.com/products/man...efrom=bluechart
Neither of those documents is much help as far as explaining how the
BlueChart charts work under MapSource on a PC or on a GPS receiver (I
use BlueChart on a 76Cx).
The behavior you describe above is best described (my words) is an issue
with zoom levels chart scales. Those two factors seem to combine to
cause the appear and disappear at various times as you pan around and
move on to and off of charts of various scales.
A good example of it is to go to Frying Pan Island at UTM 17 T 567733
5002039 or N45 10.115 W80 08.285. Center that in the MapSource screen
and then use the (+) and (-) buttons to zoom in and out. At 15 miles
you'll see no chart details, only the outlines of land masses and lakes
with a few names.
As you start zooming in, the chart details from the 1:100,000 chart
appear at the 7 mile level. As you continue to zoom in you are getting
a closer and closer view of the large scale chart details. Depending of
the amount of detail on the charts it can look like you have lost all
detail at time as there my not be any soundings or other details visible.
Eventually, when you get down to .2 miles, the details from CA2202(H)
appear. If you continue to zoom in, the "overzoom" label (warning?)
appears near the scale marker in the lower right corner. But you can
continue to zoom in if you want.
Set you zoom level to 500 feet and then start tapping the left arrow key
to start panning to the west. Eventually you will pan off of the
CA2202(H) cart and only the CA273097 will be visible. At that point
you'll get another "overzoom" warning because the software thinks you
are now over zoomed for the scale of that 1:100,000 chart. If you tap
the "-" (minus or dash) key on your PC it will back you out to the 800
foot level and the overzoom warning will go away.
The zoom levels I mention above may vary depending on the size of and
settings on your PC's video display. I am using a 1024 x 768 display on
a laptop for what I describe here.
Once you start using the charts on a GPS receiver, you'll go through a
similar overzoom warnings and changes in the amount of visible detail as
your boat moves onto and off of charts of various scales.
When I am using the 76Cx for navigation it spends most of it's time
zoomed in to the 200 to 500 foot level (as shown on the 76Cx display).
I zoom in and out some as I go from narrow coastal passes to more open
off shore areas. And as I go on and off of charts of various scales I
see the same overzoom warnings. I've just gotten accustomed to zooming
in and out to clear them, at times I simply just ignore them if I am
seeing the level of chart detail I want.
Before I shifted to the Garmin and got the BlueChart charts last year, I
had been using a Magellan Meridian Color with Magellan's BlueNav charts
(also licensed from Navionics). The BlueNav and BlueChart charts all
perform in a similar if not identical manner on Magellan and Garmin
handhelds.
The details of using the licensed Navionics charting on Garmin (or
Magellans) are not clearly explained anywhere. Navionics does not want
to talk to you about it or be of any help. They quickly got to the
point of rudeness on it and told me to talk to Magellan or Garmin.
I tried once to get help from Garmin Support by phone. The people I
talked to appeared to be pretty severely, as far as their helping me
with questions about using marine navigation products, by their being
located in Olathe, Kansas. I gave up, went away, and finally figured
things out on my own.
> Also, I have a 1 gig card in the unit. Is there a way to merely add to
> the maps that I have previously uploaded to the GPS instead of having
> to download them from the unit, add a map then upload again? It's kind
> of time consuming to add a 2 meg map to 600 meg worth already
> uploaded(40 minutes).
You have to recompile and upload the map selections to make any changes.
There is no way to add or remove a few maps. When I do map selections
I make sure I do the BlueChart in one window and save the selection to a
*.gdb file. Then I open another window and do the City Navigator
selection and save that to a *.gdb file. Then I open a third, do the
U.S. Topo selection, and save that.
Then I copy the map selections from BlueChart and Topo and paste them
into the City Navigator window. And I save that to a *.gdb file. Then
I upload the map to the microSD card in a reader with the GPS receiver
attached to the USB port to get MapSource to use the right unlock code.
I also copy the gmapsupp.img file from the microSD card back to the hard
drive to save them. Those can be copied from the hard drive to a
microSD card faster than they can be recreated from scratch. A lot of
my backing up and saving of the *.gdb files goes back to when I had
fewer and smaller microSD cards, I don't do that much any more. But I
do still save the gmapsupp.img files so I can restore one if I need to.
> BTW, if anyone can tell me how to determine the revision dates of
> various maps, such as MetroGuide or Navigator etc. much appreciated. I
> would like to know how current they all are.
In MapSource, from the Help > About MapSource > Product Info page you
can see the version numbers and copyright dates for the mapping products
and for the data sources used in each of the products. Those will give
you approximate dates of the software and data. Garmin is a little
sloppy on their software production. Some of the software I have
display a different version number from the About screens than is shown
on the CD-ROM case or sleeve (U.S. Topo 3.01 reports itself as both 2.01
and 3.01 from About, MetroGuide 3.02 reports itself as 3.01, etc.).
Jack
|