Welcome, Guest. Please login or register.

Login with username, password and session length
Forums Search:  

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - John P

Pages: [1]
Who said anything about editing? I just wanted to see what was in the files, and GPSMapEdit is the program I usually use to look at IMG files. I've had no problems with files that are part of the Northeast Topo United States series, so I was wondering what's incompatible with the USStatesandCounties ones.

Oh, I suppose the use of GPSMapEdit maybe makes it look as if I actually do want to edit stuff. No, just take a look. It usually works fine for that purpose.

Thanks for the pointer to the map creation tutorial.

I tried getting the map set placed here by Oz, but my edition of GPSMapEdit (version 0.99b, a freeware version) refuses to load any of the maps. Here's an example of the error message that it produces. Should I expect this to happen with this software?

Edited to say, the maps in the "Northeast topo" series load to GPSMapEdit just fine. So it's not that I have software that doesn't work.


Loading data from file 'C:\Program Files\GPS\IMG maps\Northeast\USStatesandCounties\54881258.img'...
* Block size:   1024
* Updated:   2008/07
WARNING: The file header contains incorrect data offset field.
ERROR: loading has terminated.
1 warning(s).
Load time is 0.00 s.

Map Making Support / Duplicate data in map files
« on: June 22, 2009, 04:23:22 PM »
A while ago I noticed that a place name on a map was wrong, and I decided to fix it up using GPSMapEdit. When I did that, the corrected name appeared overlaid with the wrong name--which made me think it had been in there twice to begin with. I exported the file from GPSMapEdit in Polish format, which is a human-readable form, and sure enough, there were identical features, now with two different names. Back in GPSMapEdit I used the command "Remove Object Duplicates", and it found plenty of them.

The file which covers my home in Massachusetts is a good example (94537047.IMG). It has a size of 9.25MB, but if you import it to GPSMapEdit, eliminate the duplicates (68470 of them!) export it and re-compile to an IMG file, it shrinks to 7.51MB. But given how long compilation takes with cGPSmapper, I'm not going to do it for very many files.

I don't want to seem like someone who's ungrateful for free stuff! Having these maps available is what really makes owning a mapping GPS receiver worthwhile, but it seems as though the files do have this excess data. I wonder if the people who create the map files are aware of it.

Map Making Support / Re: ME topo map
« on: September 25, 2008, 02:13:45 PM »
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".

Pages: [1]