Use Spectral Resampling to resample spectral data files to match one of the following:

  • The response of a known instrument (for example, AVIRIS)
  • An ASCII wavelength file, with or without full-width-half-maximums
  • The wavelengths of a specific image input file.

The resampling method you use depends on the input information. If you only provide wavelengths (band centers), ENVI assumes critical sampling and uses a Gaussian model with an FWHM equal to the band spacings.

If you provide wavelengths and FWHM information, ENVI uses a Gaussian model with FWHM spacings. If you provide a filter function, ENVI uses that for the resampling.

  1. From the Toolbox, select Spectral > Spectral Resampling. The Spectral Resampling Input File dialog appears.
  2. Select the name of a spectral data file.
  3. Click OK. The Spectral Resampling Parameters dialog appears.
  4. Follow the steps in Select Resampling Types.