[gdal-dev] Re: gdal to define projection, EPSG:3412

[Hermann Peifer]

Did you try: gdalwarp -s_srs EPSG:3412 ?

Hermann

John Callahan wrote:
> Is it possible to define/set a coordinate system using GDAL?   I 
> downloaded some data (from NSIDC) I know is in EPSG:3412.  
> (http://spatialreference.org/ref/epsg/3412/, 
> http://nsidc.org/data/atlas/epsg_3412.html)
> 
> The data is in bsq format, therefore requires a hdr file that I've been 
> piecing together manually.  The hdr file has a "projection info" line 
> that defines the projection parameters.   Here is the hdr file I've been 
> using, unsuccessfully:
> 
> ENVI
> description = {
>  File Imported into ENVI.}
> samples = 316
> lines   = 332
> bands   = 1
> header offset = 300
> file type = ENVI Standard
> data type = 1
> interleave = bsq
> sensor type = Unknown
> byte order = 0
> map info = {NSIDC Sea Ice Polar Stereographic South, 1.0000, 1.0000, 
> -3950000.0000, 4350000.0000, 2.5000000000e+004, 2.5000000000e+004, 
> Hughes 1980, units=Meters}
> projection info = {31, 6378273.0, 6356889.4, -70.000000, 0.000000, 0.0, 
> 0.0, Hughes1980, NSIDC Sea Ice Polar Stereographic South, units=Meters}
> wavelength units = Unknown
> pixel size = {2.50000000e+004, 2.50000000e+004, units=Meters}
> 
> 
> 
> The data displays properly with other vector data in EPSG:3412, say in 
> QGIS.  To me, this simply means the "map info" line of correct.  
> However, when I try to project the data (gdal_translate, gdalwarp), the 
> output is nonsense (nearly all null or nodata).  I believe my 
> "projection info" line is wrong, and may have something to do with 
> denoting the lat of origin as -90 and standard parallel as -70.   Thanks 
> for any help.
> 
> - John
> 
> **************************************************
> John Callahan, Geospatial Application Developer
> Delaware Geological Survey, University of Delaware
> URL: http://www.dgs.udel.edu
> **************************************************