User Manual - pancroma

Regression coefficients must be computed for each raw band file individually.Then the coefficients will be used to transform the raw band file into a correctedband file. PANCROMA TM has a utility for regressing three independent variable(bands) against a third dependent variable band, i.e. solving the equationY = a + b 1 X 1 + b 2 X 2 + b 3 X 3Where X1, X2 and X3 represent the independent multispectral or hyperspectralband files and Y represents the dependent band file. In order to compute theslope and intercept terms, select ‘File’ | ‘Open’ and open the dependent (Y) bandfirst, and then the X 1 , X 2 and X 3 bands. Then select ‘PreProcess’ | ‘MultipleRegression’ | ‘Three Independent Variables’. When the Data Entry box becomesvisible, select the sampling interval. (If the sampling interval is one, every DN willbe included in the computation and it will take longer. If the interval is 2, everyother DN will be computed, etc. The linear coefficient terms will be reported tothe diagnostic screen on the Main Window. They will also automatically beinserted into the Data Entry Form for subsequent use for linear transformations.We will conduct the transformations in three steps as follows. Open the Landsatblue band file. Then open the three resized pan sharpened band files so thatfour files are opened. Now compute the regression coefficients as describedabove. I accepted all of the default conditions for this example. After thecoefficients are computed, select ‘Close Graphics Window and Reset’. Nowselect ‘Pre Process’ | ‘Band Math’ | ‘Band Linear Combination’ | ‘Three Bands’. Ifyou have done everything correctly, you should see the Data Entry form alreadypopulated with your regression coefficients, looking something like the formbelow.379