Not allowing default data sources when downloading online data

normmdanormmda Global Mapper UserPosts: 5
edited September 2011 in Downloading Imagery
I want to be certain which data I download using the
"Download free maps/imagery from online sources"
option of GlobalMapper. How do I tell GM not to use
a default data source? I created a new data source
with a bogus URL (ostensibly for SRTM data), and still GM displayed
a DEM on the screen, claiming it is from the bogus source,
which, of course, is wrong.

Thank you.

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited September 2011
    I guess I'm not sure exactly what you are saying. Where did you create a bogus source and get the DEM data still displayed? There aren't any "default" data sources, you should only get data from the source that you select.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • normmdanormmda Global Mapper User Posts: 5
    edited September 2011
    After clicking on "Download free maps/imagery from online sources", I press the button "Add new source...". Responding to all the questions, I also give a bogus url for the data source. This is what I mean by a bogus data source.
    Some of the existing data sources have the following text as part of the data source description
    "[Use http://srtm.csi.cgisar.org/ if fails]
    This is what I mean by a default data source (maybe "fallback" is a better term to use).

    My question is how GM is finding data when the data source has an invalid URL, and no fallback URL is specified. I want to tell GM, that if it cannot use the URL that I specify, it must not display any data.

    Thank you
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited September 2011
    The fallback URLs aren't automatic anyway, they are for you to manually go to that web site and download data if the online source fails.

    Was your source successfully added? It shouldn't go to any other source if your URL is bad, there is not such thing as a default pass-through URL in Global Mapper, it will just give you an error. What type of source are you adding (i.e. WMS, WCS, OSM, TMS, etc.)? Are you selecting that newly added source before pressing OK to select the source?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • normmdanormmda Global Mapper User Posts: 5
    edited September 2011
    Thanks for the info.
    My source was successfully added.
    After highlighting and clicking OK, my screen gets filled with valid data,
    and at the bottom left of the GM window is the name of the bogus source that I added.
    However, I am not able to query the data source to see what URL is actually stored -- I am able only to view the category and description of the data source by right clicking on the data source entry in the list.

    My source type is WMS, as part of the TERRAIN DATA category. The name of my data source is
    "SRTM derived global elevation, 3 arc second -- PHONY"

    Maybe you can give it a try? It should only take a couple of minutes to test ...

    Thank you,
    Norm
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited September 2011
    Norm,

    What URL did you use? You shouldn't be able to add a completely phony WMS source as you have to enter a URL that provides a valid WMS GetCapabilities response and then select a layer to add the source. This wouldn't work for a phony URL so you'd never have a layer from that URL to select, you would likely be selecting from the last valid queried WMS server on the dialog where you add the source.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • normmdanormmda Global Mapper User Posts: 5
    edited September 2011
    I used the following URL
    http://phony
    or, something like that (I don't know how to query which URL my data source has stored).
    Are you saying that GM finds out this is a bogus url, and then takes the initiative to
    use the latest valid URL, instead? I would prefer a failure message, as you explained.
    Are we staring at a bug, here? :-)

    Thanks,
    Norm
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited September 2011
    Norm,

    I'm saying that if you entered http://phony on the 'Select WMS Source to Load' dialog and pressed the 'Get List of Available Data Layers' button, you would get an error and the list of layers would still be whatever it was when you opened the dialog. You can't add a WMS source from a URL until you can successfully get a list of layers from that server URL. You can tell what was used if you select the phony source that you added, then press Add Source, then select WMS for the type, then observe what URL is listed for the 'Server URL'. It will default to the URL of the selected source (if a WMS source is selected). There really isn't a way to add a phony source.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
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