[GRASS-user] Estimating import time for large data file

[Helmut Kudrnovsky]

Rich Shepard wrote
> On Sun, 31 May 2020, Markus Neteler wrote:
> 
>> I didn't confirm at all :-) It was just an information or warning.
> 
> Markus,
> 
> Using ogr2ogr was what Moritz suggested.
> 
>> I'd stick to submeter but I don't know what data you are working with
>> nor what their resolution/scale is...
> 
> This is what the *.prj file has to offer:
> 
> PROJCS["WGS_1984_Web_Mercator_Auxiliary_Sphere",GEOGCS["GCS_WGS_1984",
> DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],
> PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],
> PROJECTION["Mercator_Auxiliary_Sphere"],
> PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],
> PARAMETER["Central_Meridian",0.0],PARAMETER["Standard_Parallel_1",0.0],
> PARAMETER["Auxiliary_Sphere_Type",0.0],UNIT["Meter",1.0]]
> 
> How sub a submeter would be a good start?

is it 

EPSG:3857 [1] [2]

?

keep in mind the scope of this projection is Web mapping and visualisation
applications, not heavy GIS processing.

from [1]

"Remarks: Uses spherical development of ellipsoidal coordinates. Relative to
WGS 84 / World Mercator (CRS code 3395) errors of 0.7 percent in scale and
differences in northing of up to 43km in the map (equivalent to 21km on the
ground) may arise. "

better to use a projection appropriate to your working area.

[1] http://epsg.io/3857
[2] https://en.wikipedia.org/wiki/Web_Mercator_projection




-----
best regards
Helmut
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