This sub-directory contains passband (".pb") files, that describe
individual/combined spectral transmissions of selected
filters/instruments.
- In each file there is one line per data-point. The first column
  is the wavelength, in Angstroems. The second column contains the
  transmission.
- Comment lines must begin with `#'.
- Wavelengths must be sorted by increasing lambda.
- Spectral responses are linearly interpolated between data-points
  by SkyStuff.
- Each spectral transmission curve must explicitely begin and end
  with transmission equal to 0.

				Emmanuel BERTIN <bertin@iap.fr>
