Setting up the map archives

Gtopo is just a viewer, it does not come with maps. (I hope you are not disappointed to discover this at this stage.) To use gtopo, you will need to own or have access to a set of the NGS TOPO! series of maps on CD for the state or states that you are interested in. You can sometimes find these for a decent price on Amazon marketplace or Ebay, or your local used book store.
Of course, you can also buy them full price (typically $100 per state).

Disk strategy

Gtopo lets you copy all of your CD's onto your hard disk and then never touch them again. Each CD gets copied verbatim into its own directory, and gtopo deals with the file layout as is, creating an index to everything on disk.

Decide where on your machine you want to put all of your map data. With on the order of 0.6 Gigabyte per CD, this can add up (although in this age of 500G disks, this is hardly a big issue). This could be /home/topo or /topo or any place you find handy and logical. I would suggest /home/topo since gtopo will by default look there, but it is easy to add directories to the list that gtopo searches.

Note also that you can split up the archive. This might be handy (as it was for me), if you have a small disk in an old laptop, with two partitions, each with something like 3G of free space. In my case I put arizona maps in /u1/topo and california maps in /topo. As long as you tell gtopo about all the places where your stash maps, it will handle this all transparently for you and will build one index to all of the various places where you put maps.

Looking at this another way, you can put maps in any or all of the places that gtopo knows about, and it joins them all into one big happy archive. Look at the settings file documentation for details.

File layout

Let us say you have settled on the directory /topo for your archive. What you are going to need to do next is to feed in your CD's one by one and copy their contents to your archive.

Gtopo expects to find the contents of each CD in its own directory in the archive. It also expects each of these directories to have a name like xx_d01, where "xx" is a two letter abbreviation for the state.

At this point in time, gtopo is quite rigid about what it expects to find on disk. Directories that don't follow this pattern (names with 6 characters and a "_" as the third character) are ignored. I have some ideas about how to relax these requirements, but for now this is how it is. If you create directories for each CD and copy them as described below, everthing should work, but let me know if you find surprises.

Backcountry Explorer

This is a 17 CD set at a nice price ($55.00) which explains why so many people have it. You get the entire United States at levels 1 through 4 (so you don't get the 1:24,000 7.5 minute series maps). I don't have a copy of this to test with, but at least a couple of people have had success with it. Let me know if you are using this, so I can update this section.
If you use names like BE_D01 and so forth for your disks, it should work.

Weekend Explorer

This is a 3 CD set with "eleven popular areas near metropolitan areas". I don't have a copy, and haven't heard yet from anyone using gtopo with it, so it either "just works" or nobody has tried it yet. Let me know if you do.
Try using names like WE_D01 and so forth for your disks.

Alaska

In May of 2011, I was contacted by a fellow in Alaska who was having trouble using gtopo with his Alaskan map set. In the Alaska set, there are 3 map series rather than 5 and most mapping is a 1:63000 rather than 1:24000. As of this time gtopo does not support the Alaska maps, but work is in progress to do so now that we are aware of the situation.

Loading the maps

Copy the CD's to your archive using a command something like this: 

mount /dev/cdrom /media/cdrom
cp -var /media/cdrom/az_d02 /home/topo
Note that the above won't do for disk 1 of a set though, because that disk doesn't have a xx_d01 directory in it.

To be specific, what I did to copy the Alaska set was: 

mount /dev/cdrom
cp -var /media/cdrom /home/topo
mv /home/topo/cdrom ak_d01
umount /dev/cdrom

mount /dev/cdrom
cp -var /media/cdrom/AK_D02 /home/topo
umount /dev/cdrom

...

There is one caveat on the above though. The above works for me when I do the mount myself and control what is going on. If you let the system automounter mount the disk for you, you will see it mounted on /media/AK_D04 or some such, but if you look closely you find that there is a path like /media/AK_D04/AK_D04, and you end up with a directory in a directory that you must fix. Pay close attention and try the following. Don't blame me, the system is trying to be too helpful. 

cp -var /media/AK_D01/AK_D01 /home/topo

How and where the CD gets mounted will depend on how your system is set up, and what linux variant you are running. My latest Fedora Core system mounts the CD automatically when I insert it (so I don't need the mount command), and mounts it at a location like /media/cdrom. Your mileage will almost certainly vary, and the people that change such things seem to particularly like changing this. When the smoke clears from the above, you will find a directory with a name like /home/topo/az_d02 or /home/topo/AZ_D02. Don't worry about whether the name is upper or lower case.

The first CD in each set is unique. It holds the TOPO! software, which you probably care less about. You may be able to skip this disk entirely saving some disk space. On some state sets, this disk holds large scale map images, and if this is the case, you will definitely need it. To be safe, unless you are really hurting for disk space, copy it. Most of the sets I have duplicate the state and atlas info on the other disks, but not all do.

Repeat this process for each CD, and go ahead and include the CD 1 if you have space. If you find the directory SI_D01, you are in luck! (I found this on disk 1 of my circa 2006 Nevada Set.) This holds the entire United States at level 1, 2, and 3. Worth scrounging around to find if you don't already have it. The Alaska Set includes it also.

When you are all done, your /topo directory will look something like this: 

dr-xr-xr-x 10 tom tom      4096 Sep 26  2002 AZ_D01
dr-xr-xr-x 17 tom tom      4096 Sep 26  2002 AZ_D02
dr-xr-xr-x 15 tom tom      4096 Sep 26  2002 AZ_D03
dr-xr-xr-x 15 tom tom      4096 Sep 26  2002 AZ_D04
dr-xr-xr-x 13 tom tom      4096 Sep 26  2002 AZ_D05
dr-xr-xr-x 13 tom tom      4096 Sep 26  2002 AZ_D06
dr-xr-xr-x 16 tom tom      4096 Sep 26  2002 AZ_D07
dr-xr-xr-x 15 tom tom      4096 Jul 24  2001 AZ_D08
dr-xr-xr-x 10 tom tom      4096 Oct 24  2001 CA_D01
dr-xr-xr-x 14 tom tom      4096 Oct 24  2001 CA_D06
dr-xr-xr-x 17 tom tom      4096 Oct 24  2001 CA_D08
dr-xr-xr-x 20 tom tom      4096 Oct 24  2001 CA_D10
dr-xr-xr-x 16 tom tom      4096 Oct 24  2001 ca_d02
dr-xr-xr-x 14 tom tom      4096 Oct 24  2001 ca_d03
dr-xr-xr-x 17 tom tom      4096 Oct 24  2001 ca_d04
dr-xr-xr-x 16 tom tom      4096 Oct 24  2001 ca_d05
dr-xr-xr-x 14 tom tom      4096 Oct 24  2001 ca_d07
dr-xr-xr-x 17 tom tom      4096 Oct 24  2001 ca_d09
dr-xr-xr-x 10 tom tom      4096 Sep 21  2001 nm_d01
dr-xr-xr-x 18 tom tom      4096 May  7  2003 nm_d02
dr-xr-xr-x 16 tom tom      4096 May  6  2003 nm_d03
dr-xr-xr-x 15 tom tom      4096 May  6  2003 nm_d04
dr-xr-xr-x 15 tom tom      4096 May  7  2003 nm_d05
dr-xr-xr-x 14 tom tom      4096 May  6  2003 nm_d06
dr-xr-xr-x 15 tom tom      4096 May  6  2003 nm_d07
dr-xr-xr-x 15 tom tom      4096 May  6  2003 nm_d08
dr-xr-xr-x 13 tom tom      4096 May  6  2003 nm_d09
dr-xr-xr-x  4 tom tom      4096 Jan 10  2006 nv_d01
dr-xr-xr-x 13 tom tom      4096 Dec 10  2005 nv_d02
dr-xr-xr-x 11 tom tom      4096 Dec 10  2005 nv_d03
dr-xr-xr-x 11 tom tom      4096 Dec 10  2005 nv_d04
dr-xr-xr-x  9 tom tom      4096 Dec 10  2005 nv_d05
dr-xr-xr-x 11 tom tom      4096 Dec 10  2005 nv_d06
dr-xr-xr-x 12 tom tom      4096 Dec 10  2005 nv_d07
dr-xr-xr-x 10 tom tom      4096 Oct 18  2000 ut_d01
dr-xr-xr-x 16 tom tom      4096 Oct 18  2000 ut_d02
dr-xr-xr-x 14 tom tom      4096 Oct 20  2000 ut_d03
dr-xr-xr-x 13 tom tom      4096 Oct 20  2000 ut_d04
dr-xr-xr-x 19 tom tom      4096 Oct 20  2000 ut_d05
dr-xr-xr-x 17 tom tom      4096 Oct 18  2000 ut_d06
This is what I have on my hard disk, which has Arizona, California, New Mexico, Nevada, and Utah. You can load only the CD's you like, there is no reason to load all the CD's, and as I have said, you can safely skip loading CD 1 for each state. Note however that I found SI_D01 on disk 1 of my Nevada set.

Rearranging maps

You can do a lot of things as long as you present gtopo with directories in the repository that have the form xx_Dxx. In other words, directory names with exactly 6 characters and with "_D" or "_d" in the middle, anything else goes. Given this, you should preserve the Dxxyyy directories in those directories along with their contents. What I have done is to put all (or most) of the maps for one state onto a DVD and then have everything for say Utah in one directory UT_DVD. It is also possible to delete any part of a state rather than lumping, or to pick and choose from different states along a boundary. This kind of thing can be very useful when you have a laptop with a small hard drive.
Feedback? Questions? Drop me a line!

Gtopo / tom@mmto.org