Changes between Initial Version and Version 1 of Ticket #708, comment 13


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Timestamp:
Dec 3, 2016, 6:37:54 PM (7 years ago)
Author:
Bang Pham Huu

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  • Ticket #708, comment 13

    initial v1  
    55In short words, '''I think CRS extension only can transform from existing CRSs supported by GDAL''' (e.g: EPSG:4326 - EPSG:32633, '''but not from user defined CRS''', EPSG:4326 - FICTION:4326_upgraded (FICTION:4326_upgraded is a copy of EPSG:4326 with only change a value of angle from ''UNIT["degree",0.0174532925199433], to UNIT["degree",0.0274532925199433]'').
    66
    7 As you can see, gdal already stores the wkt of all the supported EPSG:Crss so we don't need to provide wkt as input parameter. However, if someone can understand and can create/modify an existing CRS, we can assume he can create WKT/+proj4 definition for this CRS as well (he should be a geologist and can do like this https://docs.qgis.org/2.2/en/docs/user_manual/working_with_projections/working_with_projections.html#custom-coordinate-reference-system)
     7As you can see, gdal already stores the wkt of all the supported EPSG:Crss so we don't need to provide wkt as input parameter. However, if someone can understand and can create/modify an existing CRS, we can assume he can create +proj4 definition for this CRS as well (he should be a geologist and can do like this https://docs.qgis.org/2.2/en/docs/user_manual/working_with_projections/working_with_projections.html#custom-coordinate-reference-system)
    88
    9 '''so what need to be discussed here''' is how to allow to add +proj4 manually in SECORE (proj4 is likable as it is short and straightforward), then in Petascope it can just add these parameter to encode().
     9'''so what need to be discussed here''' is how to allow to add +proj4 manually in SECORE (proj4 is likable as it is short and straightforward), then in Petascope it can just add these parameters to encode().
     10
     11
     12{{{
     13EPSG:4326
     14
     15proj4:
     16"+proj=longlat +datum=WGS84 +no_defs"
     17
     18WKT:
     19GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",
     206378137,298.257223563,AUTHORITY["EPSG","7030"]],
     21TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6326"]],
     22PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
     23UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9108"]],
     24AUTHORITY["EPSG","4326"]]
     25}}}
     26
    1027
    1128If gdal/geotool or some library can convert GML (validated by GML 3.2.1 schema) to proj4 then we just don't ask user to add the proj4 when he creates/updates definition anymore, but it is of course not what can be happened soon.