ME topo map

[savage]

I am making progress on my Maine topo map but all the data files are too big to load in Global Mapper (ran out of memory). I could easily split the map North/South but what is the best way to do it? Should I overlap the two parts? Any other comments/tricks I could use.

[-Oz-]

Is this occurring when you try to load all the files or just the dem files?

My new trick is to use my program and then it processes each quad separately so i don't have all the arcgrid/tiff files loaded at once.  If you are gonna split it I recommend splitting it along a degree line and then you won't need overlap.

I am having issues with california for this reason (trying to create a better version than what is offered now).

[savage]

First release of the Maine topo map is available here

First release of the map. Includes:

    * Contour lines (50' interval)
    * Street names, rail roads
    * Lakes, ponds and streams
    * Federal lands
    * State and counties border
    * Apalachian trail

[-Oz-]

How did you get over the ran out of memory thing?  I keep running into it with New Mexico and thus far exported the segments with roads, water, land coverage, etc as one file than the contours as another file then combine each one individually.  Processing is taking 4+hrs a piece with cgpsmapper though so that stinks.

I'll download your map soon.

[savage]

I think the problems were with the contours. I switched to the TIFF files for the South part of the map and was able to do it with all the problems I reported in other messages. ME was hard to do. I think it is easier to do it in multiple parts and combine at the end of the process.

[savage]

I realize I did not clearly answer your question.

What I did is to generate 2 sets of contours, one for the North and one for the South.
I did not change anything for the other data (water, transportation, gnis, etc).
I generated the .MP files in 2 runs. One run with the North elevations and one run with the South elevations.
Everything else is the same.

The cut between North and South is at 45 degree latitude. For the North I used Global Mapper for the contours but I use your tool for the South side. For some reasons Global Mapper could not process the South side (internal error of some sort).

[-Oz-]

Aha, what was the internal error message?

I also am now running into RGN table limits with cgpsmapper; same thing I was having with Hawaii (and have yet to resolve) is happening with New Mexico.

[savage]

There was no specific error message, just internal error or something similar.

[John P]

Hi, first I want to say thanks for making the maps available. I live in Massachusetts and I've loaded the MA one into my GPS and as far as I'm concerned, with roads and topo data, it's giving me everything I bought the GPS unit for.

I took a quick look at the maps as shown on the computer (I used GPSMapEdit). Being a railroad buff, I looked at the railroads and one thing I saw was that the Massachusetts map included the Watertown Branch of the Boston & Maine--that line closed in 1960! Clearly the database isn't very well updated.

Then I took a look at the Maine map, specifically 94537126.img, because it covers the area around Chesuncook Lake, where I went canoeing this summer. The landscape all looks right, but the name on Chesuncook Lake is "Foster Field", and because it's a large lake, the name shows up over and over. There is a "Foster Field" on the same map, or at least there should be: but when I went to see what was there, the name wasn't shown (I found it on the topo, as seen on USAPhotomaps.com). It must have wandered off to Chesuncook! This was a bit strange, but if it's just one error I wouldn't complain, considering the price. I did check a few other place names and they were all OK. But maybe this one error could be demonstrating something systematic that affects more places? I don't know if you want to hear about errors of this kind.

Edited a little while later to say that it seems that a "lake" can have only one name on the map, whereas in Maine it's common for connected bodies of water at the same level to have more than one name. Often this is a result of water levels being artificially raised by dams, which causes lakes to merge, but you'll still find the original names on the topo maps. Example is Telos Lake and Chamberlain Lake. On map 94537126.img it's all "Telos Lake", which is actually the smaller of the two (and there are other parts of the same lake with separate name, also now part of "Telos Lake"). Likewise, Eagle Lake has disappeared into "Heron-Churchill Lakes".

[savage]

All the data comes from government sites. It would be interesting to see if the Garmin maps or other topo maps have the same bugs. Maybe they use other source of information to produce their map.

I have only use the MA maps around where I live and so far it is good. I will travel to ME soon and I will see how it goes.

[smr260]

Thanks for the Maine and Massachusetts maps, they look great. 

My one issue is the elevation and contours on the Maine map - the numbers seem to be way off.  Is anybody else having this problem?  I don't know if it's my setup or something with the map itself.

[savage]

Could you give an example where you think the map is wrong?

[smr260]

If you look in the western part of the state, at the Mahoosuc Range, the elevations are all over the place.  Goose Eye Mountain is listed at 11,483 feet and all the surrounding elevations are similarly inflated.  I check around the map and it occurs over the largest area there, but I found pockets in other spots.  When you move the cursor over a mountain, it actually gives two elevations - one correct, and one very high, but when you look at the contour lines they also seem to have two or even three figures.  Here's a spot: N44.33.621 W70.58.804

[savage]

Don't know! I will investigate that in the next few days. I used the map in the northern part of the state and everything looked reasonably good but there might be something wrong in the process.

[maps4gps]

If you look in the western part of the state, at the Mahoosuc Range, the elevations are all over the place.  Goose Eye Mountain is listed at 11,483 feet and all the surrounding elevations are similarly inflated.  I check around the map and it occurs over the largest area there, but I found pockets in other spots.  When you move the cursor over a mountain, it actually gives two elevations - one correct, and one very high, but when you look at the contour lines they also seem to have two or even three figures.  Here's a spot: N44.33.621 W70.58.804

I have not looked at your map, but this sounds very strange.  The 11,483 is close to a correct elevation in feet being converted from meters to feet again!?  Sounds like data from GNIS might have been duplicated - once with a meter to feet conversion, and again with a second conversion applied.  I have not seen the 2 or 3 contour line label issue before.  Are you close to using the max
memory on your machine?