Discussion utilisateur:Matthewedwards

Re: Map tutorials / Didacticiels cartographiques

Hello Matthew.
Glad to know that somebody else follows the paths of cartography trying to improve the contents of the encyclopaedia.
Good also that you found the solution for your problem. Note that several times the modules don't seem to finish their tasks as the sentence indicating that the work is finished doesn't display but in fact they do.
GRASS is really powerful... but also a hell to handle with imo. I wrote the tutorials using this software because it was the one I found which was able to read all the basic formats, to export in SVG, free and multi-OS so anybody could use the same base, but it's not the one I use to create my own maps. Too complicated for my taste and my non-professional skills.
Greetings, and good contributions! Sting (m'écrire) 25 mai 2009 à 20:32 (CEST)

Hello Matthew. Did you find out what was the problem with the SVG file size?

For the additional data you can check this page (in French, but the Web sites are in English) where I reported the most common tools and data sources we need to create our maps here using GIS software. This particular section will guide you to the data you're looking for but there are also some useful links in the sections above in the page (the Géobase for the Canada, the World Data Bank II for boundaries and rivers at a country scale). If you don't find in the future data precise enough for one map you're creating, don't forget to make a Web search including words like bathymetry, DEM, data, GIS. Most of the time you will find this way specific data for your region of interest, but always check if this data is free to use. Note that if using GIS is the “top” in cartography, putting together data from different sources will show the limits of these data as they usually don't perfectly match together: misplaced islands, rivers which don't run in the lowest part of the valleys, etc. So you will have to make corrections, trying to guess which of the data is the most accurate. Until now I found out that the SRTM one seems to be the most reliable.

Greetings. Sting (m'écrire) 29 mai 2009 à 15:47 (CEST)

Here in the Cartographic Workshop on WP-fr we use a template which follows the conventions we set together to help us keep an unified style. I give you here the link to the English translated version which I didn't check. For the fonts, use the free DejaVu type (Sans or Serif) which is well supported by Wikimedia but prefer the < Condensed > sub-types as the standard ones give problems in rendering. You can also take a look to this page if you want to create your own colour palette for Inkscape which eases the map creation.

Greetings. Sting (m'écrire) 29 mai 2009 à 20:22 (CEST)

Re: Bathymetry

Hello Matthew.
By lack of time I didn't write any tutorial about how to integer the bathymetry in a map, but I hope I will in the coming months.
Demis data isn't useful anymore as we can have direct access to the free sources they used. To use the ETOPO1, consider it more or less like the SRTM topographic data and use it the same way. “Ice Sheet Surface” or “Bedrock Surface” has importance only on areas permanently covered by ice (Antarctica, Greenland). Click on “Create custom grids” on the left and specify the coordinates of your area of interest. For the “Grid Format”, using GRASS with “Multiple formats using GDAL”, “Binary Raster Format” with “ASCII Header” should work. You don't need 3DEM for the bathymetry, neither the GEODAS software.
I hope this helps. Don't hesitate to ask if you need more help. Greetings. Sting (m'écrire) 17 février 2010 à 13:54 (CET)

Hi. Don't worry, there's no problem.

When the data is processed, simply click on « Compress and retrieve your grid », without selecting any of the two options bellow. After the download, decompress the zip: there are two files “.flt” and “.hdr” which are the ones that will be used in your GIS software, the other ones (.htm, .gif) aren't useful. I didn't reinstall GRASS for some time now so I don't remember well, but I think that using the Multiple formats using GDAL module will work. First create a project in Lat/Lon as it's the native projection of the data (use the correct limits of your map, the grid resolution, etc.), then import the file using the above module, create another project with the cartographic projection of your choice and re-project the precedent processed data in it. Now you can export your map as a raster image.

Sorry not being able to give you more detailed step-to-step instructions, but I don't use GRASS anymore: if really powerful, I think it's much too complicated to use and I preferred to “invest” some bucks in Global Mapper which is a way more friendly-to-use software and spare time and sweat. I used GRASS for the tutorials as it was the only free multi-platform GIS software which was able to handle raster and vector data I could bring to work on my Win system at that time.

Greetings. Sting (m'écrire) 24 février 2010 à 13:17 (CET)

Re: More help with Bathymetry, please!

Hello Matthew.

Don't use those tutorials in my sandbox (Utilisateur:Sting/Brouillon/...), they are very old and are the ones I wrote first, before having a better knowledge of the available GIS data. That's why I didn't put them in the main space. You will find the 25 colors scale they use for the bathymetry in the same page (here). I took it from their forum but you can also find it (and modify it) in the preferences of the Demis Mapper software, I don't remember exactly where.

As Demis use public domain data, it's much better go directly to the source of these data.

Depending your needs you can use the ETOPO2 v2 (2' resolution), the more recent ETOPO1 (1' resolution) or even the SRTM30 Plus (30” resolution) (download page) which is the most precise free worldwide data for the bathymetry available. Note that for this last the use of the data is free but not its distribution (the raw data) which in our case doesn't matter. Note also that it contains many artefacts (tracks of the ships f.ex.) which will need correction. For the ETOPO ones, click on Create Custom Grids and enter the coordinates for your area of interest. There are more precise data available on the Internet for some specific areas, mainly the US.

After that you use these data in your GIS software like the topographic ones, which should be simple and with the advantage of having also the shadows of the relief.

If you have issues trying to use these data, just ask!

Hope this helps. Greetings. Sting (m'écrire) 28 juin 2010 à 15:48 (CEST)

P.S.: For Demis' bathymetric scale, I used the same post from their forum. I don't know if they changed it but as I said, you can check it in the preferences of their software, this if you decide to use Demis anyway.

Yes, I saw after posting that we already spoke about ETOPO earlier.

The Demis scale is the one of the left column, the 8 colors of the right column are the ones used in WP-fr (but are the old ones: they were updated since I wrote the tutorial). At that time I only specified 8 colors as 25 are far too much for a clear Web display. Since then I specified 10 colors which suit most of our needs.

You better use Demis Mapper as it uses Lat/Lon projection. You will also be able to find the limits of the map in it so you can reproject it easily. With the World Wind add-on it will be much more difficult.

Greetings. Sting (m'écrire) 29 juin 2010 à 16:11 (CEST)

Unfortunatelly I'm not using Demis Mapper for years now. It seems to be a bit more complicated than before as you mention a Mapper.NET, so I have no idea of what could be your problem. Try to contact them on their forum, for sure you will get a solution there.

Good luck. Sting (m'écrire) 1 juillet 2010 à 00:42 (CEST)

Re: Map request

Hello.
I'm downloading for the moment the dataset for that area (big problems of connections on my side) to see what I can do for you. Greetings. Sting (m'écrire) 16 novembre 2011 à 23:03 (CET)