[PROJ] Vector Data Reprojection

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Hello,

when comparing using spatialreference.org
we can find the following information: 

-------------------------

EPSG:4612

+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs 
-------------------------

EPSG:4326

+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs 
------------------------- 

And looks like they are exactly the same. Same projection
and same datum (zero to WGS84). And about the ellipses, they
are pratctically the same:

(From Wikipedia)

"The WGS 84 originally used the GRS 80 reference ellipsoid,
but has undergone some minor refinements in later editions
since its initial publication. Most of these refinements
are important for high-precision orbital calculations for
satellites but have little practical effect on typical
topographical uses. The following table lists the primary
ellipsoid parameters.

Ellipsoid reference     Semi-major axis a     Semi-minor axis b    
Inverse flattening (1/f)
GRS 80     6 378 137.0 m     ≈ 6 356 752.314 140 m     298.257 222 100
882 711...
WGS 84     6 378 137.0 m     ≈ 6 356 752.314 245 m     298.257 223 563

Equatorial (a), polar (b) and mean Earth radii as defined in the 1984
World Geodetic System revision (not to scale)

The very small difference in the flattening thus results
in a tiny difference of 0.105 mm in the semi polar axis. "

Regards: Janne.

******************************************** 

ivay kirjoitti 2019-08-20 11:31:

> Here is projection of the original shapefile with EPSG 4612. 
> 
> _GEOGCS["JGD2000",_
> 
> _    DATUM["Japanese_Geodetic_Datum_2000",_
> 
> _        SPHEROID["GRS 1980",6378137,298.257222101,_
> 
> _            AUTHORITY["EPSG","7019"]],_
> 
> _        TOWGS84[0,0,0,0,0,0,0],_
> 
> _        AUTHORITY["EPSG","6612"]],_
> 
> _    PRIMEM["Greenwich",0,_
> 
> _        AUTHORITY["EPSG","8901"]],_
> 
> _    UNIT["degree",0.0174532925199433,_
> 
> _        AUTHORITY["EPSG","9122"]],_
> 
> _    AUTHORITY["EPSG","4612"]]_ 
> 
> Thank you. 
> 
> ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ 
> On Tuesday, August 20, 2019 6:11 PM, ivay <ivaygis at protonmail.com> wrote: 
> 
>> Hi, 
>> 
>> I have a shape file with epsg 4612. 
>> I converted it into new shapefile with epsg 4326. 
>> When I opened both shape files (with 4612 and 4326 epsg codes), there is no change in the X and Y locations. 
>> Does both shapefiles (with epsg 4612 and 4326 codes) have same X and Y values? 
>> My requirement is to convert the original file with "epsg code 4612" exactly into the "epsg 4326" . 
>> Thank you for your ideas. 
>> Ivay
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