In this talk, I review the present state of our knowledge of the polarization of the coherent bremsstrahlung beam in Hall D. Many systematic issues that were observed during commissioning have been resolved with the help of data collected in Spring 2017. The leading source of remaining uncertainty is believed to come from the unknown virtual beam spot profile at the collimator. Using our Monte Carlo model, we have a direct map between the observable photon beam spot profile and the virtual electron beam spot profile that controls it in our model. With the help of a fast raster, it will be possible to measure the photon beam spot profile with accuracy in less than 40 minutes.
