[Gdal-dev] L1G Landsat data

[Frank Warmerdam]

On Wed, 2 Feb 2005 15:49:31 +0100, Stephan Holl <sholl at gmx.net> wrote:
> Thanks for answering.
> 
> Sure, you can download the data here:
> ftp://ftp.glcf.umiacs.umd.edu/glcf/Landsat/WRS2/p141/\
> r055/L71141055_05520010314.ETM-USGS.LPGS/
> (should be in one line)
> 
> Thanks for looking into this.
 
Stephan,

Looking in the _HDF.L1G file there does not seem to be any
georeferencing available.  I assume that is the file you are selecting
to get the data?  

But the _MTL.L1G file does have various supporting metadata,
including the product corners here:

    PRODUCT_UL_CORNER_LAT = 8.1775571   
    PRODUCT_UL_CORNER_LON = 79.5875317  
    PRODUCT_UR_CORNER_LAT = 8.1793694   
    PRODUCT_UR_CORNER_LON = 81.7280759  
    PRODUCT_LL_CORNER_LAT = 6.2812164   
    PRODUCT_LL_CORNER_LON = 79.5934122  
    PRODUCT_LR_CORNER_LAT = 6.2826047   
    PRODUCT_LR_CORNER_LON = 81.7250438  
    PRODUCT_UL_CORNER_MAPX = 344400.000  
    PRODUCT_UL_CORNER_MAPY = 904200.000  
    PRODUCT_UR_CORNER_MAPX = 580200.000  
    PRODUCT_UR_CORNER_MAPY = 904200.000  
    PRODUCT_LL_CORNER_MAPX = 344400.000  
    PRODUCT_LL_CORNER_MAPY = 694500.000  
    PRODUCT_LR_CORNER_MAPX = 580200.000  
    PRODUCT_LR_CORNER_MAPY = 694500.000  
...
  GROUP = PROJECTION_PARAMETERS 
    REFERENCE_DATUM = "WGS84" 
    REFERENCE_ELLIPSOID = "WGS84" 
    GRID_CELL_SIZE_PAN = 15.000000
    GRID_CELL_SIZE_THM = 60.000000
    GRID_CELL_SIZE_REF = 30.000000
    ORIENTATION = "NUP"
    RESAMPLING_OPTION = "CC"
    MAP_PROJECTION = "UTM"
  END_GROUP = PROJECTION_PARAMETERS 
  GROUP = UTM_PARAMETERS 
    ZONE_NUMBER = 44
  END_GROUP = UTM_PARAMETERS 

So if you use the current development version of GDAL you could assign
a coordinate system and bounds something like this:

gdal_translate 'HDF4_SDS:UNKNOWN:"L71141055_05520010314_HDF.L1G":0'
b10.tif -a_srs '+proj=utm +datum=WGS84 +zone=44' -a_ullr 344400 904200
580200 694500

With older versions you would need to associate the bounds bounds after
the fact with a tiff world file, since the -a_ullr flag is very new.
If you need to handle quite a few datasets, you could write a script
to harvest required metadata from the _MTL file.  I'm sorry there is no 
full solution already implemented. 

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent