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Why has a map of the entire US not been made?

Started by Jerny, January 09, 2020, 03:04:40 PM

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Jerny

I know Garmin has the 100k topo maps. I was wondering why there is not a free version. I have spent a little time making maps, and I know that it is pretty intensive to make them, but was wondering if there were other reasons. I am really new to all of this, but wanted to know if someone with more knowledge or info could shed some light on the subject.

Sorry if this has already been discussed, I searched and couldn't find anything.

Boyd


popej


jolly47roger

There are technical reasons why a single Garmin map of the US cannot be made. Garmin devices vary but are limited to a few thousand map segments and, for the maps I make from USGS, each state is a few hundred although it depends on the level of detail, too.

Boyd

#4
I'll have to disagree with that. :) Old Garmin handhelds had a limit of about 2000 map tiles.  Starting with the Oregon (IIRC) they increased that to about 4000 tiles. Most of their handhelds still have that limit, but a few of the premium new models have increased this to 10,000 (maybe 15,000, not sure).

However, there really isn't any limit on what the size of a tile can be. We have discussed this here before - it's a trade-off between the size of each tile vs the quantity of tiles. But to give a concrete example that I'm familiar with, the Garmin 100k topo that was originally distrubuted on DVD had a total of about 6500 tiles (I had this), so there was no Garmin GPS that could accomodate this whole map.

Then they introduced the Oregon 400t that included a pre-loaded version of that same map for the entire US - I bought one of these in 2008. The way they accomplished this was to use much large tiles for the same map. The pre-loaded 100k topo only had about 500 tiles total - quite a difference from the old 6500! This allowed you to have the whole US plus a lot of other maps on the GPS at the same time (the device had a 4000 tile limit).

Now that Garmin has stopped selling maps on DVD, the 500 tile version of that map is all they sell. They intentionally made the tiles very small in the old map, so it would be compatible with their very old devices with tiny amount of memory and no card slots. That was always the  real reason for making small tiles.

But aside from all this.... making your own map of the whole US would be a huge job (I"m talking about making an original map, not just re-packaging OSM data). And what would be the point? ;)

Red90

The 4 GB file limit causes a real one. You would still need more than one map.

Boyd

Not sure what you mean Red. As the OP noted, Garmin sells a topo map that covers the whole US.

https://buy.garmin.com/en-US/US/p/127633

It is pre-loaded on the "T" models of their handheld devices. I don't care for it (or any of Garmin's topo maps, for that matter), but it exists. Had it on my old Oregon 400T and the DriveTrack 71 that I got last year also had it.

The current version from the DriveTrack 71 is 3.3gb. I removed it from the device to make room for other maps and archived it on disk.

BTW... seems really ridiculous that Garmin still clings to the ancient FAT32 filesystem in 2020. The EU maps are already more than 4GB and require two files. I understand the need for compatibility with old devices, but IMO there's no excuse for still having this limit on new models.

Red90

The one Garmin sell is low resolution. I assume he is wanting to do a proper one.

Boyd

Yeah, the Garmin 100k topo isn't very good. I have had 4 different versions of it going back through the years. It used to be the only topo map that Garmin sold. At least the current version has decent roads from HERE (same as City Navigator).

But actually, if you read the OP again, he isn't asking for a better map, just a free one.  ;)

Quote from: Jerny on January 09, 2020, 03:04:40 PM
I know Garmin has the 100k topo maps. I was wondering why there is not a free version.

popej

I think the only limit for a big map is maximum of about 2048 tiles in a single mapset. Assuming size of a big tile is 10-20MB, then the maximum size of a map could be in range of 30-40GB.

I usually create maps of whole continent like Europe, Africa, South America. I have a topo map of US + Canada. It is about 12GB. Europe is 14GB.  MapInstall can cope with transfer of big maps to GPS. It creates multiple files for a single map, each file up to 4GB size.

Would anyone be interested in downloading  US Topo, which is about 8GB? I doubt, and this is the reason, that I split map of US into 8 parts with manageable sizes.

Boyd

Maybe I don't understand what you're saying Popej? As mentioned above, Garmin's old 100k US Topo had about 4500 tiles in a single mapset. It was originally distributed on multiple CD's, and later they switched to one DVD.

That is very interesting about MapInstall splitting files automatically. Didn't know it could do that!

Regarding large files, I disagree. I make big multi-level raster maps at very high resolution. They are specialized maps that only cover the small region where I live in Southern New Jersey. These are all big files and the two most popular are 15gb and 12gb with lots of downloads. https://boydsmaps.com

So IMO, if the map is something that people want, large files are not a problem (at least here in the US).

popej

I have never seen US Topo with 4500 tiles. IMO Mapsource or Basecamp could have problems with too many tiles in a mapset. Ore maybe tools we use to create mapsets have problems?

If you think big downloads are no problem, I can try to add some big maps with next release. We will see.

Boyd

Well, sorry, my memory was wrong on that point. It actually had a lot more - total of 6633 segments in Topo 2008! I had this version and an older version from around 2004? Then I have two new versions with the small segment count (about 500) that were pre-loaded on my Oregon 400t and DriveTrack 71. See this old article:

http://www.gpsinformation.net/waas/maps/topo2008.html

"The 2008 topo maps have a total of 6633 segments."

It's my opinion that large files aren't a problem in and of themselves. But in my case, these are unique maps you can't find anywhere else, so if somebody wants them, they have no choice. And my target is mostly smartphone app users, not Garmin owners. People using dedicated Garmin handhelds might be a little more.... old fashioned?  ;D

All I can say is that nobody has yet complained about file sizes. My maps load into Mobile Atlas Creator where users can send smaller portions to either a GPS or phone (like MapInstall).