I downloaded the MODIS images with HDF format from NASA EOSDIS Reverb website. And I am trying to project MOD09GQ from Sinusoidal to WGS84 using gdalwarp with Python. However, the DN value range (data type) in the output Geotiff after projecting MODIS using gdalwarp with python has been changed.
gdalwarp -of GTIFF -r near -t_srs EPSG:4326 -ot Float32 HDF4_EOS:EOS_GRID:"MOD09GQ.A2014279.h11v02.006.2015291113528.hdf":MODIS_Grid_2D:sur_refl_b01_1 20142792.tif 0...10...20...30...40...50...60...70...80...90...100 - done.
I used the above code. And I also projected the image using the MCTK of ENVI. The DN value range of the image which has processed by the MCTK is same with the original image. The DN value of the image which was processed by GDALwarp has been changed from [0,1.15] to [112,11422]. But, I set up the data type of the output Geotiff to float 32
-ot Float32. Moreover, I have tried to set up
-ot Int16 (is same with original data type of Modis). Its DN value range still was changed.
How do I keep the original DN value range (data type) after projecting MODIS using gadlwarp?