[gdal-dev] reproject python numpy binary swath/lat/lon

[Rutger]

David Hoese wrote
> 
> Thanks for the reply.  I tried the s_srs tag and it still didn't help.  
> I also tried using the -geoloc flag which I had tried earlier too and 
> still get the 441 out of 441 failed to transform error.  I have tried 
> PyTroll, but there KDTree algorithm seems to be too slow for the amount 
> of data I'm using (not sure why), I have contacted them in the past.
> 

I think their the KDTree algorithm comes from scipy. I have had some
problems with large swaths as well, on Win32 my memory was limited so i
ended up doing the resampling is small chunks. Which works, but will only
further decrease performance. 


David Hoese wrote
> 
> I'm attempting to project satellite data to an AWIPS grid.  Assuming I 
> have the grid defined correctly with proj4 parameters, I've been using 
> "+proj=latlong +datum=wgs84" as my s_srs parameters.  Does that sound 
> correct for satellite data?  So my command line call (still for testing) 
> becomes:
> 

Is it publicly available satellite data? I will give it a go myself if i
have some sample data.


David Hoese wrote
> 
> gdalwarp -s_srs "+proj=latlong +datum=wgs84" \
> -te 59.844 -123.044 14.335 -65.091 \
> -ts 5120 5120 \
> -t_srs "+proj=lcc +lon_1=-95.000  +lon_0=-113.133 +lat_2=25.0001 
> +lat_1=24.9999 +lat_0=16.369" \
> -geoloc -of GTIFF \
> image.vrt out.tif
> 
> The output grid is 5120x5120 and I wasn't sure if -te was lat/lon 
> points, but that's what I used.  -te has lat/lon of upper left pixel of 
> the grid and lat/lon of the lower right pixel of the grid.  Does any of 
> this look correct?  Thanks for the help.
> 

Geographic WGS84 (lat/lon) is an obvious choice if you're not sure, but its
not necessarily correct. As you can see, your Lambert target projection has
coordinates in a similar value range, so you cannot be sure just based on
the values alone.
The syntax for gdalwarp seems alright to me. Because you're outputting to a
rather large area (geographically), it might be useful to test it for a
small subset first to rule out difficulties in finding a proper
transformation, although im not sure if it could help in this case.

Regards,
Rutger

--
View this message in context: http://osgeo-org.1560.n6.nabble.com/gdal-dev-reproject-python-numpy-binary-swath-lat-lon-tp4978609p4981173.html
Sent from the GDAL - Dev mailing list archive at Nabble.com.