Spectrum Spatial (SSA/LIM)

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  • 1.  Building a Tile set from Rasters that are not EPSG:3857

    Posted 12-20-2017 03:22

    Hi,

    I have lots of imagery that is in the projection EPSG:28355 and I would like to use it to build a Tile set that I can use as a Basemap in SSA alongside the Bing Basemaps.

    I know that I can reproject this imagery to EPSG:3857 and then create a Tile set in SSA and that works as I would expect.

    I've also noticed that I can create a map in any projection and then create a EPSG:3857 Tile set that point to this data even though its not the same projection. However I've only been able to get this to work if the source map is vector, it apears to me that Spectrum will not reproject any raster data on-the-fly.

    Is this correct or am I missing something?



  • 2.  RE: Building a Tile set from Rasters that are not EPSG:3857

    Posted 12-21-2017 04:28

    Hi Duri

    That is correct - raster and grid files cannot be re-projected on the fly by Spectrum Spatial. When SSA renders a map it asks for it in the projection of the current base map in SSA (often this is EPSG:3857) and whilst vector data can be re-projected, raster tables will throw an error and mo map is returned (you can see the error in the browsers developer tools).

     

    We are planning to make use of client side re-projection in SSA in a future release (which is now supported in Openlayers), which will overcome this issue. This would include projecting Bing to EPSG:28355 or your imagery to EPSG:3857 in the client. In the meantime the only option is to ensure that all base maps (and any other raster files added) are in the same projection as each other.



  • 3.  RE: Building a Tile set from Rasters that are not EPSG:3857

    Posted 12-21-2017 18:24

    Thanks Mustafa

    It will be good to have client side reprojections, I look forward to seeing this feature.

    Duri



  • 4.  RE: Building a Tile set from Rasters that are not EPSG:3857

    Posted 12-28-2017 05:14

    Vector datasets can be re-projected onto the base mapping



  • 5.  RE: Building a Tile set from Rasters that are not EPSG:3857

    Posted 01-05-2018 05:54

    Reprojecting rasters is processor intensive and should be avoided if possible. Only if you don't know your target projection or it could be one of many, or your rasters are vast, is it worth paying the price for projecting on the fly. If possible, I always reproject (and resample) rasters into their target format in order to minimise real-time processing. GDAL is a great open source tool for doing this. FME also, but I think that uses GDAL under the hood too.