It seems interesting I'll keep a note on this :) The question is how you can build a VRT mosaic directly from MODIS hdf files, because the problem is that you have to mosaic first and after that to transform them to the EPSG:4326 projection. If you transform them first and mosaic them after you might have white lines.
--Nikos 2011/7/25 Brian Case <[email protected]> > anna, Nikolaos, > > after much experimentation I found something that seems to work. > > gdalwarp --config GEOL_AS_GCPS FULL \ > -tps -geoloc -t_srs EPSG:4326 \ > -te -119.88004906118 13.5092548294379 \ > -92.6036641645677 34.7070050511582 \ > HDF4_EOS:EOS_SWATH:"MOD02HKM.A2011169.1750.005.NRT.hdf":MODIS_SWATH_Type_L1B:EV_500_RefSB > \ MOD02HKM.A2011169.1750.005.NRT.tif > > note i tried to escape the newlines to make it easy to read but the > email may mess that up. > > there is about 2.7 million gcp's in a normal 5min modis swath file, by > default gdal only reads every 10th row and column of gcp's this is not > enough to handle the bowtie effect. > > > Brian > > On Tue, 2011-01-18 at 16:33 -0800, Nikolaos Hatzopoulos wrote: > > You are right, I notice that there isn't any difference from the > > band_1.tiff and band_1_warp.tiff > > > > --Nikos Hatzopoulos > > > > On Mon, Jan 17, 2011 at 8:15 AM, anna auge <[email protected]> wrote: > > Hi all, > > > > I am trying to convert modis level 1B data (type SWATH) to > > geotiff following these steps. > > > > 1) Examining the HDF > > gdalinfo d:\modis\1b > > \MOD021KM.A2011008.0850.005.2011008195744.hdf > > gdalinfo HDF4_EOS:EOS_SWATH:"d:\modis\1b > > > \MOD021KM.A2011008.0850.005.2011008195744.hdf":MODIS_SWATH_Type_L1B:EV_1KM_RefSB > > 2) Extracting the 1. band of the subdataset > > MODIS_SWATH_Type_L1B:EV_1KM_RefSB > > gdal_translate -of GTiff -b 1 HDF4_EOS:EOS_SWATH:"d:\modis\1b > > > \MOD021KM.A2011008.0850.005.2011008195744.hdf":MODIS_SWATH_Type_L1B:EV_1KM_RefSB > d:\modis\1b\band_1.tiff > > 4) Warping the image to WGS84 > > gdalwarp -t_srs EPSG:4326 d:\modis\1b\band_1.tiff d:\modis\1b > > \band_1_warp.tiff > > > > The example dataset, which i am using, can be downloaded here > > > ftp://ladsftp.nascom.nasa.gov/allData/5/MOD021KM/2011/008//MOD021KM.A2011008.0850.005.2011008195744.hdf > > > > And now to my problem: I get always an certain shift > > ( > http://www.flickr.com/photos/54033867@N00/5363471425/in/photostream/), > which is avoided if i am using the "Georeference MODIS" option in ENVI ( > http://www.flickr.com/photos/54033867@N00/5364083966/in/photostream/). > > I also tried a few workarounds, f.g. > > http://thread.gmane.org/gmane.comp.gis.gdal.devel/10482, but > > nothing worked properly. > > As far as I understand gdal supports Modis L1B SWATH, so what > > I am doing wrong? Any help is appreciated. > > > > Regards Anna > > > > P.S. I am using FWTools 2.4.7 on Windows > > > > > > > > WEB.DE DSL Doppel-Flat ab 19,99 ยค/mtl.! Jetzt mit > > gratis Handy-Flat! > > http://produkte.web.de/go/DSL_Doppel_Flatrate/2 > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev > > >
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