I have sample points in an Excel file with XY coordinates and canopy density. I also have a Landsat ETM+ image. All points are collected from the same area as in the image.
- I exported all sample points by first ‘Display XY data’ and then ‘Export data’, thus I got a shapefile.
- I used "Sample" extracted all points from ETM+ image, then I got a table and exported it to a DBF file. In the DBF file I have XY coordinates for all sample points and band values.
- Then I copied all band values from DBF to original sample points Excel file, then I calculated NDVI and did linear regression (canopy density as dependent variable and NDVI as independent variable) in Excel. Therefore I got a regression equation.
- After added the Excel to ArcGIS and joined it to sample points shapefile, I carried out OLS. However, I only got all sample points regressed.
What could be the problem and how should I apply regression equation to the image so I can produce a map?