Spectrum Spatial (SSA/LIM)

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  • 1.  Support for GDA2020 MGA55 (EPSG 7855) as a base layer

    Posted 03-26-2024 02:23

    Hi,

    I haven't been able to find a specific answer as to whether EPSG 7855 is supported as a base layer in SSA. My experience in SSA v2018.1 is as follows:

    1. Business layers are in EPSG 7855 and display with no problem.
    2. Within Project Settings, I add a EPSG 7855 tile layer (created in Spatial Manager) as a base map and set it as default.
    3. Within the Extents tab I specify the new base layer:

    After saving settings and selecting the project within SSA, the coordinate system in use defaults to a different projection - seemingly taken from the next base layer available (Bing, in this case):

    Note that projected GDA94 (EPSG 28355) is supported as a base layer in 2018.1.

    My questions are:

    A) Are my findings correct - that EPSG 7855 is not supported as a base layer in 2018.1?

    B) If so, in which layer is it supported (if any)?

    C) If it is not supported, what is the recommended approach?

    Thanks.



    ------------------------------
    James Nolet
    GIS Manager
    Caf Consulting
    Mentone office, VIC, Australia
    ------------------------------


  • 2.  RE: Support for GDA2020 MGA55 (EPSG 7855) as a base layer

    Posted 21 days ago
    Edited by Duri Bradshaw 21 days ago

    Hi James,

    I suspect it might be a version issue as its look good in version 2023.1

    Sorry I don't have a 2018.1 test server anymore.



    ------------------------------
    Duri Bradshaw
    Spatial IT Consultant
    Insight GIS
    ------------------------------

    Original Message


  • 3.  RE: Support for GDA2020 MGA55 (EPSG 7855) as a base layer

    Posted 5 days ago

    Hi Duri,

    Thanks for giving this a go - I greatly appreciate it and the feedback.  This pretty much confirms my conclusion.  It would have been good if this information was available in official Precisely documentation but I guess we don't want things to be too easy - or we'd be out of a job!

    (Sorry for my delayed reply but Community posts haven't been getting through to me via email lately.)



    ------------------------------
    James Nolet
    GIS Manager
    Caf Consulting
    Mentone office, VIC, Australia
    ------------------------------

    Original Message


  • 4.  RE: Support for GDA2020 MGA55 (EPSG 7855) as a base layer

    Posted 21 hours ago
    Edited by Duri Bradshaw 21 hours ago

    Hi James,

    Your post got me thinking and I remembered seeing this in some documentation, so I had a bit of a look and found this in the 12.2 documentation but cant see it in 12.1 Spectrum Spatial Guide

    Does the title render in 7855 even though the basemap is 3857? I can't remember which version allows for mixed projections in basemaps but I would have thought 18.2 allows this. If not does it render if you add the title as a business map? 


    ------------------------------
    Duri Bradshaw
    Spatial IT Consultant
    Insight GIS
    ------------------------------

    Original Message


  • 5.  RE: Support for GDA2020 MGA55 (EPSG 7855) as a base layer

    Posted 20 hours ago

    Hi Duri,

    As the documentation says, GDA2020 is supported in 18.2.  I assumed this meant it would be supported as a base layer, but that is not the case (as far as I can tell).

    In 12.1 or 12.2, to ensure that the map is rendered as GDA94 Zone 55 we had to have a base map in this projection.  I recall that all business maps needed to use the same coordinate system back then.  With the upgrade to 2018.2, I believe this was not the case.  We still needed the base map to be in the desired projection, but business maps did not need to match.  They would be transformed on the fly, to match the base map.

    Since GDA2020 Zone 55  (EPSG 7855) is supported in 18.2, I assumed this would still be the case for this newer projection.  I just needed to ensure that the base map is now in 7855.  But SSA does not recognise it.  It defaults to the coordinate system of the next base map down - 3857 in this case.  The map is then rendered in this coordinate system.  All business maps are transformed on the fly to match the base map.

    Incidentally, all business maps are in EPSG 7855 as well as the base map.  So SSA is recognising EPSG 7855 for the business maps - it is just that they are being transformed on the fly to match the base map.  As soon as we are able to specify an EPSG 7855 base map we should be right.  At least, this was the case for GDA94 Zone 55 (EPSG 28355).

    Thanks again for your help.



    ------------------------------
    James Nolet
    GIS Manager
    Caf Consulting
    Mentone office, VIC, Australia
    ------------------------------

    Original Message