Six Mueller matrix estimates trigonometry function fitting for all altitudes and azimuths. The QQ and QU terms are on top. The UQ and UU terms are in the middle. The QV and UV terms are on the bottom. The top graphic shows spectral order at 6225 Å. The bottom graphic shows spectral order at 8601 Å with much reduced circular polarization cross-talk (low QV and UV values). The sinusoidal variation in the linear polarization terms represent the transformation between the altitude-azimuth frame and a Zenith based polarization frame.