Galactic + M101 ISP correction is based on an "Epoch 5" observation of
SN2011fe made on 2011 November 28 UT at the Steward Observatory 61" Kuiper
Telescope with the SPOL spectropolarimeter.

The adopted ISP in the sightline to SN2011fe is:

q_max = -0.0013664                  P = 0.199%; theta = 66.62 degrees
u_max =  0.0014526

where it is assumed that the wavelength of maximum ISP is at 5550 Angstroms.
The ISP spectrum is assumed to follow a Serkowski law.

The spectra ISP_epoch5.q and ISP_epoch5.u within this directory show the
adopted ISP from 4000 to 7550 Angstroms.