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wiki:exercise1 [2017/12/05 22:53] (current)
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 +__Open the Landsat image with the image viewer openev:__
 +<code bash>
 +openev -h ${LANDSATDIR}/​${LANDSATIMG}
 +</​code>​
 +
 +__Select different band settings (false colour images)__
 +
 +consult web page with landsat bands for different thematic band settings
 +<note important>​natural (true) colour image for Landsat imagery: R=band 3(red), G=band 2 (green), B=band1 (blue)</​note>​
 +zoom in on particular area of interest
 +  * method 1: + button
 +  * method 2: control button + drag window
 +  * method 3: control button + left mouse button
 +zoom out from particular area of interest
 +  * method 1: - button
 +  * method 2: control button + right mouse button
 +  * method 3: use fit all layers button (square box with arrow in each corners)
 +
 +__create vector with forested areas by selecting forest from cornwall_natural.shp and reprojecting to epsg:3035 (ETRS89:​LAEA)__
 +<code bash>
 +ogr2ogr -t_srs epsg:3035 -where "TYPE in ('​forest'​)"​ ${VECTORDIR}/​cornwall_forest_3035.shp ${VECTORDIR}/​cornwall_natural.shp
 +</​code>​
 +
 +__open forest vector in openev on top of landsat raster image__
 +
 +question: can you distinguish forest from other vegetated areas?
 +
 +question: can you easily distinguish forest from inland water?
 +
 +__select the standard false colour composite__
 +
 +<note tip>​standard false colour image for Landsat: R=band 4(NIR), G=band 3(red), B=band2(green)</​note>​
 +
 +Interesting web sites for interpreting Landsat images:
 +
 +http://​web.pdx.edu/​~emch/​ip1/​bandcombinations.html
 +
 +http://​zulu.ssc.nasa.gov/​mrsid/​tutorial/​Landsat%20Tutorial-V1.html
 +
 +<note tip>Do not forget to enhance raster when loading new bands using button with horizontal line</​note>​
 +
 +question: what does vegetation look like in this false colour image, why?
 +
 +question: what about water and forest now?
  
wiki/exercise1.txt ยท Last modified: 2017/12/05 22:53 (external edit)