Hello all<br><br>I would like to reproject (to WGS84) an HDF raster image dataset.<br>The problem is that I am not quite sure of what I should be using for the GCP extraction and so which geographic data from within the HDF SDSs..<br>
On tail with this email I have copied the output from gdalinfo on my main HDF file containing multiple SDSs...<br><br>Do I need to use the Latitude/Longitude SDSs&nbsp; (subdatasets 11, 12 ) from the reprojection operations? Can anyone point me out on how I could possibly do this as<br>
to get a correctly georeferenced images? One which will not look like a swath scanned image, but a skewed and correctly referenced one...<br><br>Hint: The image data covers a big part of China... hence, the reprojection needs to take into account this... probably reprojecting onto WGS84 ??<br>
Any suggestions would be appreciated...<br><br>Other problem is that out of the SDSs that I have, I would like to extract 8 bit raster images (from 16 bit unsigned ones in subdataset 0) ... Now, I have been trying to approach this problem in different ways and still cannot figure out which would be the best... Is it better to extract the SDS into a separate HDF file first with hdp? Can I do the task by using hdftor8 directly?? By using gdal_translate for the first decomposition?? Any other options ??<br>
<br>Best regards...<br><br>gdalinfo output:<br><br>Driver: HDF4/Hierarchical Data Format Release 4<br>Files: AMOD021KM20070104035343.hdf<br>Size is 512, 512<br>Coordinate System is `&#39;<br>Metadata:<br><br>&nbsp;GRINGPOINTLATITUDE.1=64.763542175293, 58.4916687011719, 20.8642158508301, 24.1079616546631<br>
&nbsp; GRINGPOINTLONGITUDE.1=91.4718399047852, 134.930770874023, 110.696083068848, 88.3426055908203<br><br>.... OTHER METADATA ....<br><br>&nbsp; EASTBOUNDINGCOORDINATE=134.930768655651<br>&nbsp; WESTBOUNDINGCOORDINATE=88.3307203917252<br>
&nbsp; NORTHBOUNDINGCOORDINATE=64.7989342568829<br>&nbsp; SOUTHBOUNDINGCOORDINATE=20.7060304288409<br><br>.... OTHER METADATA ....<br><br>Subdatasets:<br>&nbsp; SUBDATASET_1_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:0<br>
&nbsp; SUBDATASET_1_DESC=[15x4630x1354] EV_1KM_RefSB (16-bit unsigned integer)<br>&nbsp; SUBDATASET_2_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:1<br>&nbsp; SUBDATASET_2_DESC=[15x4630x1354] EV_1KM_RefSB_Uncert_Indexes (8-bit unsigned integer)<br>
&nbsp; SUBDATASET_3_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:2<br>&nbsp; SUBDATASET_3_DESC=[2x4630x1354] EV_250_Aggr1km_RefSB (16-bit unsigned integer)<br>&nbsp; SUBDATASET_4_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:3<br>
&nbsp; SUBDATASET_4_DESC=[2x4630x1354] EV_250_Aggr1km_RefSB_Uncert_Indexes (8-bit unsigned integer)<br>&nbsp; SUBDATASET_5_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:4<br>&nbsp; SUBDATASET_5_DESC=[2x4630x1354] EV_250_Aggr1km_RefSB_Samples_Used (8-bit unsigned integer)<br>
&nbsp; SUBDATASET_6_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:5<br>&nbsp; SUBDATASET_6_DESC=[5x4630x1354] EV_500_Aggr1km_RefSB (16-bit unsigned integer)<br>&nbsp; SUBDATASET_7_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:6<br>
&nbsp; SUBDATASET_7_DESC=[5x4630x1354] EV_500_Aggr1km_RefSB_Uncert_Indexes (8-bit unsigned integer)<br>&nbsp; SUBDATASET_8_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:7<br>&nbsp; SUBDATASET_8_DESC=[5x4630x1354] EV_500_Aggr1km_RefSB_Samples_Used (8-bit unsigned integer)<br>
&nbsp; SUBDATASET_9_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:8<br>&nbsp; SUBDATASET_9_DESC=[16x4630x1354] EV_1KM_Emissive (16-bit unsigned integer)<br>&nbsp; SUBDATASET_10_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:9<br>
&nbsp; SUBDATASET_10_DESC=[16x4630x1354] EV_1KM_Emissive_Uncert_Indexes (8-bit unsigned integer)<br>&nbsp; SUBDATASET_11_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:10<br>&nbsp; SUBDATASET_11_DESC=[926x271] Latitude (32-bit floating-point)<br>
&nbsp; SUBDATASET_12_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:11<br>&nbsp; SUBDATASET_12_DESC=[926x271] Longitude (32-bit floating-point)<br>&nbsp; SUBDATASET_13_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:12<br>
&nbsp; SUBDATASET_13_DESC=[926x271] Height (16-bit integer)<br>&nbsp; SUBDATASET_14_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:13<br>&nbsp; SUBDATASET_14_DESC=[926x271] SensorZenith (16-bit integer)<br>&nbsp; SUBDATASET_15_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:14<br>
&nbsp; SUBDATASET_15_DESC=[926x271] SensorAzimuth (16-bit integer)<br>&nbsp; SUBDATASET_16_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:15<br>&nbsp; SUBDATASET_16_DESC=[926x271] Range (16-bit unsigned integer)<br>&nbsp; SUBDATASET_17_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:16<br>
&nbsp; SUBDATASET_17_DESC=[926x271] SolarZenith (16-bit integer)<br>&nbsp; SUBDATASET_18_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:17<br>&nbsp; SUBDATASET_18_DESC=[926x271] SolarAzimuth (16-bit integer)<br>&nbsp; SUBDATASET_19_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:18<br>
&nbsp; SUBDATASET_19_DESC=[926x271] gflags (8-bit unsigned integer)<br>&nbsp; SUBDATASET_20_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:19<br>&nbsp; SUBDATASET_20_DESC=[4630x1354] EV_Band26 (16-bit unsigned integer)<br>
&nbsp; SUBDATASET_21_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:20<br>&nbsp; SUBDATASET_21_DESC=[4630x1354] EV_Band26_Uncert_Indexes (8-bit unsigned integer)<br>&nbsp; SUBDATASET_22_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:21<br>
&nbsp; SUBDATASET_22_DESC=[16x10] Noise in Thermal Detectors (8-bit unsigned integer)<br>&nbsp; SUBDATASET_23_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:22<br>&nbsp; SUBDATASET_23_DESC=[16x10] Change in relative responses of thermal detectors (8-bit unsigned integer)<br>
&nbsp; SUBDATASET_24_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:23<br>&nbsp; SUBDATASET_24_DESC=[463x16x10] DC Restore Change for Thermal Bands (8-bit integer)<br>&nbsp; SUBDATASET_25_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:24<br>
&nbsp; SUBDATASET_25_DESC=[463x2x40] DC Restore Change for Reflective 250m Bands (8-bit integer)<br>&nbsp; SUBDATASET_26_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:25<br>&nbsp; SUBDATASET_26_DESC=[463x5x20] DC Restore Change for Reflective 500m Bands (8-bit integer)<br>
&nbsp; SUBDATASET_27_NAME=HDF4_SDS:UNKNOWN:&quot;AMOD021KM20070104035343.hdf&quot;:26<br>&nbsp; SUBDATASET_27_DESC=[463x15x10] DC Restore Change for Reflective 1km Bands (8-bit integer)<br>Corner Coordinates:<br>Upper Left&nbsp; (&nbsp;&nbsp;&nbsp; 0.0,&nbsp;&nbsp;&nbsp; 0.0)<br>
Lower Left&nbsp; (&nbsp;&nbsp;&nbsp; 0.0,&nbsp; 512.0)<br>Upper Right (&nbsp; 512.0,&nbsp;&nbsp;&nbsp; 0.0)<br>Lower Right (&nbsp; 512.0,&nbsp; 512.0)<br>Center&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (&nbsp; 256.0,&nbsp; 256.0)<br><br>-- <br>Mattia<br>