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Which map(s) should I install

Started by Little German, January 18, 2011, 01:00:09 PM

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Little German

I just bought a Garmin 450. I am using it for geocaching with my family, I am confused on which maps are best or recommended for this. What if I want to do this in multiple states???

maps4gps

Which area(s) are you interested in?  What type of 'data' do you feel you need (routing, contours, detailed hydro, most recent city streets, trails, etc)?   Have you looked at the listing of what is available for your area of interest.

Boyd

Only you can answer this question. Since the maps on this site are free, just look at the listings for the states you want, choose some and try them. If you don't like them, try some more.

If you are really confused and this seems too complicated, you might consider buying Garmin's US Topo 100k. It has its shortcomings, but for a newcomer it's not a bad start if you can afford it. You can purchase on a pre-loaded data card that just plugs into your 450 and you will have the entire US available. Cost is about $100, maybe less if you shop around.

Little German

I loaded the topo maps for Nevada and California. They are 1.25 GB +/-
I was wondering how can garmin do the whole North America when this device only supports a 4 GB card?
Is this the only way to do that?
Thanks for the replies!

maps4gps

The less detail the less space required.
If you mean Garmin's City Navigator North America; their CN products are primary transportation and people type POI (points of interest) - very basic hydro, no contour lines and no elevations in gridded format to product 3D views.
It is more a matter of a 4000 segment/tile/quad limit; the Gbyte limit is the most a single file can be; many are using 8 and/or 16Gb memory cards.

Little German

So if I wanted to have several states on my gpsr I would have to look for less detailed maps and download them all?

Boyd

You can use a 16GB card in your Oregon - I am in my 400t. Garmin has a lot of confusing and misleading information of their website that should be updated. The main reason you might want a big card would be to use BirdsEye imagery however. That can take up quite a lot of space.

Garmin's full US Topo 100k is just under 3GB. Like maps4gps says, it's all about the amount of detail. Map size is based on area, and hence it's a squared function. When we say "100k" that means the map scale is 1:100,000 or that objects on the map are 1/100,000 of their actual size.

So if you take a square section of a 100k map and cover the same area at 24k resolution (1:24,000) it would be 4 maps across by 4 maps high. That would be 16x the amount of data to cover the same area (the map would be 16x more detailed). It would also (theoretically) take 16x the amount of storage space.

Now that may not really hold true for vector based digital maps the same as it would for a scan of a paper map, but the principle is what's important. Higher resolution maps require more space to store.

maps4gps

That CA topo map is overly large due to an inappropriate contour interval being used.  About 2/3's of the CA 24k USGS topo quads use a 40' or even 80' CI, while the CA topo used 20' for the entire State.  You may find using my US planimetric (no contours) southwest along with my CA 40'contour overlay mapsets more suitable to you needs. 

FYI - you do not have to upload and entire State to your GPSr; you can select one or many quads/tiles or all of them for upload.  See the tutorials: http://www.gpsfiledepot.com/tutorials/how-to-open-maps-in-mapsource/ and http://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/

Little German