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mfurlend/Difference between EPSG 4326 & 3857

Forked from keum/Difference between EPSG 4326 & 3857
Created November 21, 2016 00:33
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  1. @keum keum renamed this gist Nov 7, 2015. 1 changed file with 6 additions and 3 deletions.
    9 changes: 6 additions & 3 deletions gistfile1.txt → Difference between EPSG 4326 & 3857
    View file
    Original file line number Diff line number Diff line change
    @@ -1,7 +1,8 @@
    EPSG: 4326 uses a coordinate system on the surface of a sphere or ellipsoid of reference.
    WGS 84 - Earth as Geoid. -Mercator

    EPSG: 3857 uses a coordinate system PROJECTED from the surface of the
    sphere or ellipsoid to a flat surface.
    sphere. Earth as perfectly sphere. -Web Mercator

    Think of it as this way:

    @@ -19,7 +20,9 @@ You want your GeoJSON to be this. Leaflet likes this and does the projection to
    An interesting tid bit about 900913 is that it is GOOGLE in digits (like when you play with a calculator).
    They did this until EPSG made them a valid projection.

    web mercator == spherical mercator == google mercator == Web Mercator (Auxiliary Sphere)

    web mercator NOT == spherical mercator
    google mercator == Web Mercator (Auxiliary Sphere)

    Loading data to Mapbox Studio/TileMill has to be in WGS 84, Mercator EPSG:4326
    Once those data gets uploaded, it converts into EPSG:3857 WebMercator.

  2. @keum keum revised this gist Dec 23, 2013. 1 changed file with 5 additions and 2 deletions.
    7 changes: 5 additions & 2 deletions gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -12,9 +12,12 @@ EPSG 3857 uses a coordinate system the same as a MAP (flat surface).
    Convert GDAL to convert HARN NAD83 Washington North (EPSG of 2926) into Web mercator WGS84 (EPSG of 4326)

    From NICK:
    TileMill and Github are going to be using the same, Spherical Mercator. EPSG4326 is Plate Carree (Geographic), meaning that it is NOT yet transformed to a projection. You want your GeoJSON to be this. Leaflet likes this and does the projection to Web Mercator for you.
    TileMill and Github are going to be using the same, Spherical Mercator.
    EPSG4326 is Plate Carree (Geographic), meaning that it is NOT yet transformed to a projection.
    You want your GeoJSON to be this. Leaflet likes this and does the projection to Web Mercator for you.

    An interesting tid bit about 900913 is that it is GOOGLE in digits (like when you play with a calculator). They did this until EPSG made them a valid projection.
    An interesting tid bit about 900913 is that it is GOOGLE in digits (like when you play with a calculator).
    They did this until EPSG made them a valid projection.

    web mercator == spherical mercator == google mercator == Web Mercator (Auxiliary Sphere)

  3. @keum keum revised this gist Dec 23, 2013. 1 changed file with 11 additions and 1 deletion.
    12 changes: 11 additions & 1 deletion gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -9,4 +9,14 @@ EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface).
    EPSG 3857 uses a coordinate system the same as a MAP (flat surface).


    Convert GDAL to convert HARN NAD83 Washington North (EPSG of 2926) into Web mercator WGS84 (EPSG of 4326)
    Convert GDAL to convert HARN NAD83 Washington North (EPSG of 2926) into Web mercator WGS84 (EPSG of 4326)

    From NICK:
    TileMill and Github are going to be using the same, Spherical Mercator. EPSG4326 is Plate Carree (Geographic), meaning that it is NOT yet transformed to a projection. You want your GeoJSON to be this. Leaflet likes this and does the projection to Web Mercator for you.

    An interesting tid bit about 900913 is that it is GOOGLE in digits (like when you play with a calculator). They did this until EPSG made them a valid projection.

    web mercator == spherical mercator == google mercator == Web Mercator (Auxiliary Sphere)



  4. @keum keum revised this gist Dec 11, 2013. 1 changed file with 2 additions and 1 deletion.
    3 changes: 2 additions & 1 deletion gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -1,6 +1,7 @@
    EPSG: 4326 uses a coordinate system on the surface of a sphere or ellipsoid of reference.

    EPSG: 3857 uses a coordinate system PROJECTED from the surface of the sphere or ellipsoid to a flat surface.
    EPSG: 3857 uses a coordinate system PROJECTED from the surface of the
    sphere or ellipsoid to a flat surface.

    Think of it as this way:

  5. @keum keum revised this gist Dec 11, 2013. 1 changed file with 2 additions and 1 deletion.
    3 changes: 2 additions & 1 deletion gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -4,7 +4,8 @@ EPSG: 3857 uses a coordinate system PROJECTED from the surface of the sphere or

    Think of it as this way:

    EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface). EPSG 3857 uses a coordinate system the same as a MAP (flat surface).
    EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface).
    EPSG 3857 uses a coordinate system the same as a MAP (flat surface).


    Convert GDAL to convert HARN NAD83 Washington North (EPSG of 2926) into Web mercator WGS84 (EPSG of 4326)
  6. @keum keum revised this gist Nov 13, 2013. 1 changed file with 4 additions and 1 deletion.
    5 changes: 4 additions & 1 deletion gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -4,4 +4,7 @@ EPSG: 3857 uses a coordinate system PROJECTED from the surface of the sphere or

    Think of it as this way:

    EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface). EPSG 3857 uses a coordinate system the same as a MAP (flat surface).
    EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface). EPSG 3857 uses a coordinate system the same as a MAP (flat surface).


    Convert GDAL to convert HARN NAD83 Washington North (EPSG of 2926) into Web mercator WGS84 (EPSG of 4326)
  7. @keum keum created this gist Nov 12, 2013.
    7 changes: 7 additions & 0 deletions gistfile1.txt
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,7 @@
    EPSG: 4326 uses a coordinate system on the surface of a sphere or ellipsoid of reference.

    EPSG: 3857 uses a coordinate system PROJECTED from the surface of the sphere or ellipsoid to a flat surface.

    Think of it as this way:

    EPSG 4326 uses a coordinate system the same as a GLOBE (curved surface). EPSG 3857 uses a coordinate system the same as a MAP (flat surface).