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QGIS is a free, open source, cross platform (lin/win/mac) geographical information system (GIS)
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.kap files, OSM no longer georeferenced #39630

Closed SV-Pelagia closed 4 years ago

SV-Pelagia commented 4 years ago

Never had a problem with this until last week or so:

When I bring in a .kap file as a raster layer, it comes in without any georeference (CRS?). I can zoom to layer to see it, but its lat/lon coordinates are nonsensical.

Same .kap files work fine in chartplotting software such as OpenCPN. (I even downloaded fresh new test kap/bsb files from NOAA -- still no luck

File comes in with "Unknown CRS"

Name 12323_1
Path C:\CHARTS\RASTER\TEMP\BSB_ROOT\12323\12323_1.KAP
CRS Unknown CRS: PROJCRS["Global Mercator",BASEGEOGCRS["WGS 84",DATUM["World Geodetic System 1984",ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4326]],CONVERSION["unnamed",METHOD["Mercator (variant B)",ID["EPSG",9805]],PARAMETER["Latitude of 1st standard parallel",0,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8823]],PARAMETER["Latitude of natural origin",0,ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9122]]],PARAMETER["Longitude of natural origin",-74,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8802]],PARAMETER["False easting",0,LENGTHUNIT["Meter",1],ID["EPSG",8806]],PARAMETER["False northing",0,LENGTHUNIT["Meter",1],ID["EPSG",8807]]],CS[Cartesian,2],AXIS["easting",east,ORDER[1],LENGTHUNIT["Meter",1]],AXIS["northing",north,ORDER[2],LENGTHUNIT["Meter",1]]] - Projected
Extent -48810.0743519349925919,4755289.5712047731503844 : 39636.3257532024435932,4863264.4713630015030503
Unit meters
Width 13388
Height 16344
Data type Byte - Eight bit unsigned integer
GDAL Driver Description BSB
GDAL Driver Metadata Maptech BSB Nautical Charts
Dataset Description  
Compression  
Band 1  
More information  
Dimensions X: 13388 Y: 16344 Bands: 1
Origin -48810.1,4.86326e+06
Pixel Size 6.60639379333264376,-6.60639379333264376
gioman commented 4 years ago

@SV-Pelagia please attach/link a sample.

SV-Pelagia commented 4 years ago

http://www.charts.noaa.gov/RNCs/12323.zip

gioman commented 4 years ago

@SV-Pelagia the fact that the layer comes up with an unknown CRS it does not means it has no valid CRS,in fact here the layer works ok when adding a basemap

Screenshot_20201027_110249

it seems the CRS used by these maps is a custom one, so QGIS says is "unknown".

SV-Pelagia commented 4 years ago

Thanks gioman! Your comment made me check again...

I tried setting OSM as the basemap. Wouldn't display correctly. But then I noted the coordinates at the bottom were all wrong -- turns out it was set to incorrect EPSG. Changed to EPSG 4326 and presto, the coordinates came out correct, and various".kap" files came in fine.

I THOUGHT I had previously set the EPSG correct -- never had a problem with this. Perhaps some "update" to software?

Whatever, it works now. Thank you for responding quickly.