You cannot use aerosol retrieval with SPOT data because it does not have appropriate bands. You can either choose to perform no aerosol retrieval and use a standard model with a fixed visibility.
http://www.harrisgeospatial.com/docs/...
The water column multiplier you use is dependent on the model atmosphere you choose. A multiplier can be used to customize the amounts as desired.
http://www.harrisgeospatial.com/Suppo...