User Manual - pancroma

The next step is to overlay the Landsat channels over the spectrum. I did this inPower Point although you can use any convenient graphics editor.I then struck horizontal lines that marked the intersection of the Landsat bandswith the spectral curve. My strategy was to require that the reflectance be “atleast” as large as the peaks and “no more than” for the valleys. The next stepwill show how the LSA allows such discrimination.A note of caution: there are five “Lawn Grass” spectra listed and six “Grass”spectra, none of them exactly the same. I chose one arbitrarily to see what Iwould get. In reality, library spectra may be useful but it is best not to place blindfaith in them, as we shall soon see. The best spectra are the ones that comefrom a reliable source directly from your target area. You should at least read theDocumentation that accompanies each USGS spectrum.Now we are ready to scan our data. Select ‘File’ | ‘Open and open six or sevenLandsat band files, band1 (Blue), band2 (Green), band3 (Red), band4 (NIR)band 5 (SWIR) and band 7 (LWIR), or alternatively use the Thermal Infrared(TIR) band. If you decide to use the TIR band, open the files in the order:band1, band2, band3, band4, band5, band6 (TIR) and band 7. Now select‘Spectral Analysis’ | ‘Landsat Spectral Analyzer’ | ‘Six/Seven DN Bands’.IMPORTANT NOTE: Using the TIR band may give additional discriminatingpower to your analysis. If you decide to use the TIR band, you may have to238