I've been bad at posting daily, but I will get better. Since Monday, update, I've read the RR Lyrae and BHB star papers. The RR Lyrae one had V-band magnitudes, which was useful as a jumping-off point, even though it's not one of the LSST filters. The BHB paper has magnitudes as a function of metallicity, which gave me some pause because the metallicities in the simulation are higherthan expected. For now I'm using RR Lyrae stars as tracers.
I also had some difficulty resolving the proper-motion discrepancy, which turns out to have mainly been caused by my own negligence of units. Now that everything's in MAS per year, the differences are much smaller (though not quite zero). I'm both happy and frustrated about that, as I spent a good deal of time trying to find some deep underlying cause when most of the problem was simple oversight. Now that the proper motions are in better shape I've started to convolve them with LSST errors and make plots of "observations." I'm not 100% on how to make plots of vx versus vy for different radial bins other than by oplotting each bin onto the graph, so that's teh next thing to learn about IDL.
As far as the FoS simulation is going, it seems like starfish and x11 don't get along so well, and Joe Cammisa has been great in helping out with that so far. I've also started to try binning the halo particles into 'pixels,' which ran into a snag with the where() function, which now believes that all of the stars are in all of the bins. I also looked at the code for smoothing filters and am a bit unsure of it. The FoS idea seems more intimidating the more I think about it.