I haven't worked with MERIS on NDVI data but I know about MODIS:<br>
<br>
so let's say we have four MODIS files lvl3 data:<br>
MOD13Q1.A2010113.h08v04.005.2010133194933.hdf<br>
MOD13Q1.A2010113.h08v05.005.2010134041223.hdf<br>
MOD13Q1.A2010113.h09v04.005.2010135200404.hdf<br>
MOD13Q1.A2010113.h09v05.005.2010133080730.hdf<br>
<br>
if you go to the map:<br>
<a href="https://lpdaac.usgs.gov/lpdaac/products/modis_overview">https://lpdaac.usgs.gov/lpdaac/products/modis_overview</a><br>
<br>
you are going to see that these tiles represent the west coast<br>
<br>
what I do is extract the data from hdf to geotiff<br>
<br>
if you do gdalinfo MOD13Q1.A2010113.h08v04.005.2010133194933.hdf<br>
<br>
you are going to have:<br>
...<br>
SUBDATASET_2_NAME=HDF4_EOS:EOS_GRID:"MOD13Q1.A2010113.h08v04.005.2010133194933.hdf":MODIS_Grid_16DAY_250m_500m_VI:250m
16 days EVI<br>
SUBDATASET_2_DESC=[4800x4800] 250m 16 days EVI MODIS_Grid_16DAY_250m_500m_VI (16-bit integer)<br>
SUBDATASET_3_NAME=HDF4_EOS:EOS_GRID:"MOD13Q1.A2010113.h08v04.005.2010133194933.hdf":MODIS_Grid_16DAY_250m_500m_VI:250m
16 days VI Quality<br>
SUBDATASET_3_DESC=[4800x4800] 250m 16 days VI Quality MODIS_Grid_16DAY_250m_500m_VI (16-bit unsigned integer)<br>
SUBDATASET_4_NAME=HDF4_EOS:EOS_GRID:"MOD13Q1.A2010113.h08v04.005.2010133194933.hdf":MODIS_Grid_16DAY_250m_500m_VI:250m
16 days red reflectance<br>
SUBDATASET_4_DESC=[4800x4800] 250m 16 days red reflectance MODIS_Grid_16DAY_250m_500m_VI (16-bit integer)<br>
<br>
...<br>
<br>
you do:<br>
<br>
gdal_translate
'HDF4_EOS:EOS_GRID:"MOD13Q1.A2010113.h08v04.005.2010133194933.hdf":MODIS_Grid_16DAY_250m_500m_VI:250m
16 days NDVI' image1.tif<br>
0...10...20...30...40...50...60...70...80...90...100 - done.<br>
<br>
so you will have your first tif<br>
<br>
you do the same for the others files<br>
<br>
and you will have:<br>
image1.tif<br>
image2.tif<br>
image3.tif<br>
image4.tif<br>
<br>
we are going to make a virtual mosaic using the vrt format:<br>
<br>
gdalbuildvrt mosaic.vrt *.tif<br>
<br>
if you open in a text editor the mosaic .vrt you are going to see the details<br>
<br>
now we are going to convert the mosaic to WGS84 projection<br>
gdalwarp -t_srs WGS84 mosaic.vrt final.tif<br>
<br>
my final.tif does not have any lines<br><br><div class="gmail_quote">On Thu, Jul 7, 2011 at 5:02 PM, katrin eggert <span dir="ltr"><<a href="mailto:katrineggert1980@gmail.com">katrineggert1980@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Greetings<div>I'm using gdalwarp to reproject a few tiles from platecarré to UTM WGS84 (for a specific zone). Originally they are tiles so they don't have any "blank" space between them but when I reproject to UTM I get a few areas in the borders of the image. What can I do to still have a perfect match between tiles?</div>
<div>Thanks</div><div>Kat</div>
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