http://osgeo-org.1803224.n2.nabble.com/file/n5838904/gdalwarp_problem.doc gdalwarp_problem.doc
Hi there, I was trying to use GDALWARP command to do the NTv2 transformation on some German map data (raster data). However I have come across a lot of errors saying "failed to find a grid table for the location". I used the same grid shift file and the same projection settings in the ogr2ogr command to do the NTv2 transformation on the MapInfo map data files (vector data) we have got . It seems working perfectly without any error message. The grid shift file was downloaded from http://translate.google.com/translate?js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&sl=de&tl=en&u=http%3A%2F%2Fcrs.bkg.bund.de%2Fcrseu%2Fcrs%2Fdescrtrans%2FBeTA%2Fde_dhdn2etrs_beta.php this link . I am not sure whether I have used the GDALWARP command correctly. It seems that I got the error messages for all the raster map data I have got here by running the GDALWARP command to do the NTv2 transformation on them. I have attached two screenshots for your reference. As follows, please find the GDAL command I was using and some the error messages copied from the FWTools shell window. Note that I have turned on the debug mode before running the command in FWTools shell window: C:\Program Files\FWTools2.4.7>gdalwarp -s_srs "+proj=tmerc +lat_0=0 +lon_0=12 +k =1.000000 +x_0=4500000 +y_0=0 +ellps=bessel +datum=potsdam +nadgrids=C:\fh\comar ch\BETA2007.gsb +units=m +wktext" -t_srs "+proj=utm +datum=WGS84 +zone=32" C:\fh \comarch\backdrops\s4_01_01\l0.tif C:\fh\comarch\backdrops\s4_01_01\l0_test.tif pj_open_lib(proj_def.dat): call fopen(C:\PROGRA~1\FWTOOL~1.7\proj_lib\proj_def.d at) - succeeded pj_open_lib(proj_def.dat): call fopen(C:\PROGRA~1\FWTOOL~1.7\proj_lib\proj_def.d at) - succeeded Processing input file C:\fh\comarch\backdrops\s4_01_01\l0.tif. pj_open_lib(proj_def.dat): call fopen(C:\PROGRA~1\FWTOOL~1.7\proj_lib\proj_def.d at) - succeeded pj_open_lib(proj_def.dat): call fopen(C:\PROGRA~1\FWTOOL~1.7\proj_lib\proj_def.d at) - succeeded pj_open_lib(C:\fh\comarch\BETA2007.gsb): call fopen(C:\fh\comarch\BETA2007.gsb) - succeeded NTv2 DHDN90 62x84: LL=(5.5,47) UR=(15.6666667,55.3) pj_apply_gridshift(): failed to find a grid shift table for location (5.0347670dW,55.2216906dN) tried: C:\fh\comarch\BETA2007.gsb 0pj_apply_gridshift(): failed to find a grid shift table for location (5.0350256dW,55.2215588dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.0350256dW,55.2215588dN) tried: C:\fh\comarch\BETA2007.gsb NTv2 - loading grid DHDN90 pj_open_lib(C:\fh\comarch\BETA2007.gsb): call fopen(C:\fh\comarch\BETA2007.gsb) - succeeded pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): failed to find a grid shift table for location (5.0350534dW,55.2212791dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.0350534dW,55.2212791dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): failed to find a grid shift table for location (5.0350813dW,55.2209994dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.0350813dW,55.2209994dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): used DHDN90 pj_apply_gridshift(): failed to find a grid shift table for location (5.0351091dW,55.2207198dN) tried: C:\fh\comarch\BETA2007.gsb ................................. ................................. ................................. pj_apply_gridshift(): failed to find a grid shift table for location (5.1075622dW,54.4761871dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.1075622dW,54.4761871dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.1075888dW,54.4759073dN) tried: C:\fh\comarch\BETA2007.gsb pj_apply_gridshift(): failed to find a grid shift table for location (5.1075888dW,54.4759073dN) tried: C:\fh\comarch\BETA2007.gsb 100 - done. I did not copy all the error messages here as there are quite an amount of messages. Although we did get some resulting file after running this command, I did not manage to see anything (just blank) when opening the files in our map data/image tools. I am just wondering whether you are aware of any reason why this happens. Your help would be much appreciated. Thanks & Best Regards, Heng -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/An-issue-about-using-GDALWARP-to-do-the-NTv2-transformation-tp5838904p5838904.html Sent from the GDAL - Dev mailing list archive at Nabble.com. _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
