[Gdal-dev] GMU WCS Server supports netCDF

[Denis Nadeau]

Frank,

Netcdf now support UTM and LCC. 
TM projection works fine with WCS data from NWGISS server .

I have checked for uniform grid spacing in projected values at three places 
in the image:
left, middle and right 
If I establish that spacing is uniform accross the map, I enable the 
GeoTransform, 
otherwise it stays disable. 

But I need help with LCC metadata found in the test file RUC.nc. 
I used osr.SetLCC1SP with STD_PARALLEL as dfScale. (Probably wrong...) 
I just don't know what to do with these values for Lamber Conformal Conic :

standard_parallel=25
longitude_of_central_meridian=-95
latitude_of_projection_origin=25
GRIB_earth_shape=spherical
GRIB_earth_shape_code=0

You can see that False_Easting an False_Northing are missing so, I set them 
to 0 which is probably wrong too.

Finallly, for latitude/longitude data, I use WKT "WGS84". 
(I also check for uniform grid spacing as before ...)



Regards,
Denis


2005/8/26, Frank Warmerdam <fwarmerdam at gmail.com>:
> 
> Denis,
> 
> The GMU WCS NetCDF file now reports:
> 
> Coordinate System is `'
> Origin = (94.692708,6.738066)
> Pixel Size = (0.00271231,-0.00268426)
> 
> Corner Coordinates:
> Upper Left ( 94.6927079, 6.7380663)
> Lower Left ( 94.6927079, 4.8295543)
> Upper Right ( 96.8978175, 6.7380663)
> Lower Right ( 96.8978175, 4.8295543)
> Center ( 95.7952627, 5.7838103)
> 
> But, I am not sure how this could be. The file is apparently
> projected in transverse mercator, but those are lat/long values.
> The file presumably is not projected in lat/long so the lat/long
> pixel size will not be consistent across the image. It is important
> we only set the geotransform based on the lat/lon (or projected values)
> if we can establish that the pixel spacing is uniform across the
> dimension maps.
> 
> In this file, we should be picking up the TM values from the xdim and
> ydim arrays.
> 
> ... phone call from you ...
> 
> Well, I think we have covered this mostly on the phone now, but i'll
> send what I had in the email so far.
> 
> Best regards,
> --
> 
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up | Frank Warmerdam, 
> warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush | Geospatial Programmer for Rent
>
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