Adjust Attitude Estimator Sun Vector Error Representation

[kylekrol]

Currently, we define our expected sun vector distribution as a spherical coordinate representation plus or minus a predetermined uncertainty in phi and theta. While the sun vector is around the equator this is alright as a given step in phi or theta traverse a similar distance on the unit sphere. If the expected sun vector, however, is near a pole (plus or minus z), this representation is no longer consistent.

We need to define a local error distribution around the expected sun vector for this to work more consistently.

[shihaocao]

[shihaocao]

[shihaocao]

First time scale was on the order of day : hours : mins