Displaying Landsat ETM+

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07-02-2010 11:21 AM
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New Contributor
Hi there,
I'm an archaeologist trying to integrate Landsat ETM+ imagery to a regional survey in the Bolivian Amazon Basin. I've downloaded a file from the Global Land Cover Facility (http://glcf.umiacs.umd.edu)
that came in L1G format. So far I have followed the directions given at this web page "http://glcf.umiacs.umd.edu/library/guide/fileformat.shtml", and "http://glcf.umiacs.umd.edu//library/pdf/fileguide_l1g_arcgis.pdf" but I'm having problems with step 2, creating a World File.
According to the first link I should be able to find all the information needed in the metadata file, but there is SO MUCH information there that I don't know what should I copy to the hdr file and what should the the correct name of the hdr file. Without it I try to import the data, the files load but Im not able to see anything.
I am attaching the metadata file to this post. Could anyone give me hand making the world file? Maybe I'm doing something wrong? can anyone post a better tutorial on how to use Landsat ETM+ files in ArcMap 9.3?
Thanks a lot
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Occasional Contributor III
I am quite sympathetic. All the different file formats for remote sensing data can be quite a challenge. I would check if GeoTiff's are available for this scene. Historically GeoTiff was the format GLCF distributed data in. As far as I can tell here is what your header (hdr) file should look like for bands 1-5 and 7 (will need a separate hdr file for each band).

Image BSQ header file
nrows 6951
ncols 7871
nbands 1
nbits 8
layout bsq
skipbytes 0
ulxmap 210000.000
ulymap 8505000.000
xdim 30
ydim 30

Here is the info I extracted from the metadata for the reflectance bands (1-5 & 7).
nrows - PRODUCT_SAMPLES_REF = 7871 (Can't remember if this is row or col)
ncols - PRODUCT_LINES_REF = 6951 (Can't remember if this is row or col)   
ulxmap - PRODUCT_UL_CORNER_MAPX = 210000.000 (Looks like UTM coord for zone -20)
ulymap - PRODUCT_UL_CORNER_MAPY = 8505000.000  (Looks like UTM coord for zone -20)
xdim - GRID_CELL_SIZE_REF = 30.000000
ydim - GRID_CELL_SIZE_REF = 30.000000

Here is where it gets tricky. The data is band-sequential so when you import bands 6H, 6L (thermal) and 8 (panchromatic) you will need to change the header info to reflect different row,column dimensions and cell resolutions. The suffix in the metadata for bands 1-5 & 7 - "REF", for 6L and 6H - "THM", and band 8 - "PAN".

As soon as you get this working I would export each band into a grid and then use MAKESTACK (available in raster calculator) to make an image stack for multispectral viewing.
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I am quite sympathetic. All the different file formats for remote sensing data can be quite a challenge. I would check if GeoTiff's are available for this scene. Historically GeoTiff was the format GLCF distributed data in. As far as I can tell here is what your header (hdr) file should look like for bands 1-5 and 7 (will need a separate hdr file for each band).

Image BSQ header file
nrows 6951
ncols 7871
nbands 1
nbits 8
layout bsq
skipbytes 0
ulxmap 210000.000
ulymap 8505000.000
xdim 30
ydim 30

Here is the info I extracted from the metadata for the reflectance bands (1-5 & 7).
nrows - PRODUCT_SAMPLES_REF = 7871 (Can't remember if this is row or col)
ncols - PRODUCT_LINES_REF = 6951 (Can't remember if this is row or col)   
ulxmap - PRODUCT_UL_CORNER_MAPX = 210000.000 (Looks like UTM coord for zone -20)
ulymap - PRODUCT_UL_CORNER_MAPY = 8505000.000  (Looks like UTM coord for zone -20)
xdim - GRID_CELL_SIZE_REF = 30.000000
ydim - GRID_CELL_SIZE_REF = 30.000000

Here is where it gets tricky. The data is band-sequential so when you import bands 6H, 6L (thermal) and 8 (panchromatic) you will need to change the header info to reflect different row,column dimensions and cell resolutions. The suffix in the metadata for bands 1-5 & 7 - "REF", for 6L and 6L - "THM", and band 8 - "PAN".

As soon as you get this working I would export each band into a grid and then use MAKESTACK (available in raster calculator) to make an image stack for multispectral viewing.


Thank you so much for your help, I've been trying to figure this out by myself for long, since I'm right now down in the field. I created the hdr file but it doesnt seem is being read by ARCmap when I add the HDF file. Could it be because of naming convention? how do you relate a specific .hdr to the dataset?
so far, the file I created is named L712320070_07020000612_HDF.hdr, same name as the L712320070_07020000612_hdf.bsq.

am I missing something?

Thank you again.
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Ok, I figured it out, you need one file FOR EACH BAND literally.
Thank you so much for your help, the ETM+ panchromatic band is awesome, I've been working with 3 arc second STRMs for very long, I'm super excited about this.
Can anyone point me into a good resource to properly use the rest of the bands? I really want to learn how to work with this data.
Thanks
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Occasional Contributor III
You can perform some simple visualization by creating an image stack using the MAKESTACK command. This is a legacy Workstation ArcInfo command but is available in Spatial Analyst's raster calculator. The usage would look like this (no spaces in path name):
MAKESTACK C:\YourPath\stackname LIST C:\YourPath\band1 C:\YourPath\band2 ...

This will create a dataset that has all of your bands contained within. When you add this image stack to ArcMap you get an RGB color composite. You can change which color gun a band is assigned to in the datasets properties. 

Here is a nice introduction to multispectral band composites
http://www.crisp.nus.edu.sg/~research/tutorial/opt_int.htm 

For actual classification there are some tools available in ArcGIS (i.e., Maximum Likelihood Classification). However, if you are interested in classification I would recommend taking a look at a the following open source (free) remote sensing software.   

MultiSpec (Documentation has nice introduction to image classification)
http://cobweb.ecn.purdue.edu/~biehl/MultiSpec/

OSSIM
http://www.ossim.org/OSSIM/OSSIM_Home.html

ILWIS
http://www.itc.nl/Pub/research/Research_output/ILWIS_-_Remote_Sensing_and_GIS_software.html

SPRING
http://www.dpi.inpe.br/spring/english/

You may also be interested in BASP (The Bonn Archaeological Software Package)
http://super3.arcl.ed.ac.uk/baspmirror/basp.html
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New Contributor III
do you have access to envi / envi ex? you can open the header file directly there to get the information you need..
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