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Coordinatesystems in MiPro

  • 1.  Coordinatesystems in MiPro

    Posted 11-26-2021 05:42
    Hi there,

    when i do trainings in MiPro it's allways a sure laugh when it comes to choose a new coordinate-system, and you have all participants sitting there with this "you must be joking" Expression on their faces:
    What: You cannot search for a coordinate system?
    What: You cannot search for an EPSG-Code?
    What: Not every coordinate-system definition is associated with an EPSG-Code?
    What: The list of categories is not even sorted in any way?
    ...that makes looking for the right coordinate system real fun.

    When looking for the official German Federal coordinate system: UTM 32N based on ETRS89 with the EPSG-Code 25832,
    it gets even worse:
    I think anyone would suggest to find it in a category named UTM.... but

    no, there it isn't.
    If you know what to search for you can find it in the PRJ-File here:

    "--- Danish Bounded Coordinate Systems---"
    "Bounded UTM Zone 32 ETRS89\p25832", 2008, 115, 7, 9.0, 0, 0.9996, 500000, 0, 50000.0, 5750000.0, 1050000.0, 6750000.0
    "Bounded UTM Zone 33 ETRS89\p25833", 2008, 115, 7, 15.0, 0, 0.9996, 500000, 0, -200000.0, 5750000.0, 800000.0, 6750000.0

    "--- Lithuanian Coordinate Systems ---"
    "UTM Zone 34 (EUREF89)\p25834", 8, 115, 7, 21, 0, 0.9996, 500000, 0
    "UTM Zone 35 (EUREF89)\p25835", 8, 115, 7, 27, 0, 0.9996, 500000, 0

    "--- ETRS Transverse Mercator (ETRS89) ---"
    "ETRS TM Zone 32, Northern Hemisphere (ETRS89)\p3044", 8, 115, 7, 9, 0, 0.9996, 500000, 0
    "ETRS TM Zone 33, Northern Hemisphere (ETRS89)\p3045", 8, 115, 7, 15, 0, 0.9996, 500000, 0
    "ETRS TM Zone 34, Northern Hemisphere (ETRS89)\p3046", 8, 115, 7, 21, 0, 0.9996, 500000, 0
    "ETRS TM Zone 35, Northern Hemisphere (ETRS89)\p3047", 8, 115, 7, 27, 0, 0.9996, 500000, 0

    So MiPro calls this a Danish Coordinate System (Hi Peter H., - it's not exclusivly yours!)
    You can find the same crs under "ETRS Transverse Mercator", - why is it called ETRS Transverse Mercator,
    when it is called UTM in Danish & Lithuanian Coordinate Systems? It's the same definition.

    From my point of view it would be consequent to rename the ETRS Transverse Mercator - Kategorie to 
    Universal Transverse Mercator (ETRS89) so that one is able to find it, or what would you think?

    Now MiPro 2021 can use GDAL to open some more file formats, but wait, - what about coordinate systems here?

    Just yesterday a customer send me a shape file that he wasn't able to open with mipro, but he claimed, that it was in UTM 32N ETRS89.
    When trying to open it with the new GDAL-Format-Option i got this dialog:

    without any possibility to change the sourcefile coordinate system. I suggest, this relys on the ability of gdal to get the crs from the file,
    but remember: the *.prj-File of a shapefile is optional, and not mandatory. So if there isn't such a file, even gdal get's lost.
    When i tried an ogrinfo on that file, it told me, that the crs is unknown.

    In the end i found out, that the file was in a coordinate system mipro doesn't know anything about, EPSG 5650 (..UTM 32N with leading 32 in the x-coordinate), so i generated the missing lines for the customer Mapinfow.prj-File and he could translate it via UT.

    But the thing is: GDAL does know this CRS, so ogr2ogr can translate from 5650 to 25832,
    and since MiPro 2021 utilizes GDAL in the background, this should be technicaly possible with MiPro 2021, - if you were able to choose the right crs when opening the file.

    Would be great to have this option in a future version!

    best regards

  • 2.  RE: Coordinatesystems in MiPro

    Posted 11-28-2021 14:31
    Hi Stephan,

    You would be just the right man to review my "Projection Explorer" app on the Windows Store!

    It is just a demo, and it is free. Download it from the Windows Store by searching for "Projection Explorer" by Roberts Geospatial Engineering.

    It is based on the MapInfo PRJ file and allows you to search for your desired projection using EPSG code or any other text or by clicking on a world map, in addition to searching by category. It has some of the improvements you are asking for but still suffers from some of the limitations.

    The app uses EPSG code extensively and many of the coordinate systems in the PRJ file do not have an EPSG code, which is an annoying limitation. However, it would probably be hard work to comprehensively upgrade the PRJ file. Worth talking about though! Maybe someone could write some software to semi-automate the process by matching with the EPSG database.

    Let me know if you like it! The app will soon appear as a projection selection tool in some new software I am going to release early next year called ProRaster.
    Projection Explorer search dialog

    Sam Roberts
    Founder, Roberts Geospatial Engineering