[gdal-dev] ogr2ogr vector central meridian change, vector offset issue.

[Ilia Koen]

Hello all,
     The same re-projection issue is not fixed by the -wrapdateline . 
Here is a screenshot of the issue 
http://dukodestudio.com/client_room/coralreefs/robinson_projection-offsetlineissue.png

This is used to reproject the bluemarble.
gdalwarp -s_srs EPSG:4326 -t_srs '+proj=robin +lon_0=-90 +x_0=0 +y_0=0' 
world.topo.200407.3x5400x2700.geo.tif 
world.topo.200407.3x5400x2700.robin(-90).tif

and this to re- project the countries outline to the robinson projection.
ogr2ogr -overwrite -wrapdateline -s_srs EPSG:4326 -t_srs '+proj=robin 
+lon_0=-90 +x_0=0 +y_0=0' -spat -180 -90 180 90 countries_robin.shp 
countries.shp

Is it possible to fix the offset lines with some sort of processing in 
gdal ?

I was thinking that one way to fix this is to rasterize the countries 
outline while at EPSG:4326 and then warp it to the robinson projection. 
But then I will loose the vectors to rasters.

Any suggestions or work practices are welcome !
Best ik.


On 3/6/11 3:24 PM, Ilia Koen wrote:
> Hello,
>     We are trying to re-project the coral reef dataset via ogr2ogr for 
> the dataset to fit the bluemarble projection. The coral reef is a 
> vector shape dataset and it is using the Lambert Cylindrical Equal 
> Area at -160 central meridian. Once we re-project we are getting lines 
> connecting the shapes that are cutoff at the edges from -180 to 180. 
> Is that a bug ? or  are we doing something wrong?
>
> You can see the offset issue here 
> http://dukodestudio.com/client_room/coralreefs/coralReefData-offsetlineissue.png 
>
>
> Here is the location of the dataset 
> http://www.wri.org/publication/reefs-at-risk-revisited#datasets
>
> Our command is as follows:
> ogr2ogr  -s_srs '+proj=cea +lon_0=-160 +lat_ts=0 +x_0=0 +y_0=0' -t_srs 
> EPSG:4326 reefPoly28.shp reef_500_poly.shp
>
> We did try to use the "-spat -180 -90 180 90" flag with the above 
> commnd but without success.
>
> Thanks, ik.
>
>
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