[cdt-l] topo maps

[cdt-l@mailman.backcountry.net (Jeff Braun)]

A couple of other topo map options also exist. I have previously pointed
out the the USGS maps for MT, ID, WY, and NM are available for free.
These are DRGs or geotif maps at 250 dpi.  The compressed file size are
about 3 Mbytes. I downloaded the Montana and Yellowstone maps and burned
them onto two CDs.

Links are available through:

http://mcmcweb.er.usgs.gov/drg/free_drg.html

I tried the TopoZone Map Factory demo, those are at 125 dpi. The nice
thing about these maps is it looks like adjacent maps are spliced
together for you.  Since the resolution is lower, these maps should
download faster if you are doing it through a modem. My quick tests
through a high speed connection actually downloaded about twice as fast
from WY  than Topozone, despite the file being twice as big (3MB vs. 1.5
MB) for maps covering the same amount of area.

The CDTS lastest Dividends issue also noted that they now offer a CD
with all of the USGS 1:100,000 scale maps covering the entire CDT.  I
believe the price was $35 and includes software to view and print them.
They have not updated their Marketplace page yet, but you probably can
get more info through gorp.com/cdts

Jeff

Jonathan Ley wrote:

> The TOPO! statewide CD-ROMs are $200 each!  The
> maps from these are really nice - seamless and
> they offer contour shading.  TOPO! does offer
> CD-ROMs of smaller areas for like $50 (I have
> a couple of them for Washington).  They do print
> decent maps, but they're no better than the
> topozone maps - Both are just scanned USGS maps.
> (In fact, the topozone scans are actually a higher
> quality - the white background is actually white.
> On the TOPO! maps, it's an eggshell shade)
>
> I've found that it helps to adjust the "gamma" of
> the topo maps (from either source) to about 0.50
> using some kind of graphical editing software (I
> have Corel).  This makes the minor topo lines
> easier to read.
>
> Also, by importing the maps to Corel, I can erase
> non-critical parts of the maps to save on printing
> costs (for example, if the trail follows a river for
> 10 miles, there isn't much added value to a map
> which shows miles of surrounding mountains.)
>
> This new "map factory" feature on topozone gives it
> the same flexibility as the TOPO! CD-ROMs - I can
> export the files to Corel and edit them.  For those
> of you interested, this is what I do -
> -Select a 1:24000 map at 2100 x 3000 pixels
> -Import the file to corel and adjust the gamma to
> 0.5 (and crop off un-needed stuff if warranted)
> -Print on high-quality paper at 650DPI, using a
> print scaling factor of 50%.
>
> This gives a crisp image (even smallest text is
> readable) that's 8" x 10" printed, & about 1 mile
> to the inch.  I've also found that prints on high-
> quality paper don't "bleed" when they get wet.
> With a lot of moisture, they will get blurry, but
> it takes a lot!
>
> I'm really liking these 8" x 10" maps - a lot easier
> to handle than some big folding nightmare & in full
> color.  I have yet to see how many I can print with
> one ink cartridge though.
>
> -Jonathan
>
> PS: there's also another company - maptrails.com
> that is like TOPO! & has a CD-ROM of Colorado
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