LSST Image Simulations

The precise measurements planned for the Large Synoptic Survey Telescope (LSST) require careful algorithmic studies before the telescope begins operating with its unprecedented image production rate. The LSST Image Simulation group is leading the effort to simulate the LSST system from end-to-end using a high fidelity framework. We first synthesize input astrophysical object catalogs that include stars based on a galaxy model, asteroids, and cosmologically-based galaxy catalogs with morphological parameters. We then use a novel approach to simulate images using a photon Monte Carlo approach. We draw photons from the objects using their spectral energy distributions and propagate those photons through the Universe, atmosphere, telescope, and camera using complex wavelength-dependent photon simulation physics. We describe the simulation framework, and discuss the photon simulation approach that has been used generate millions of high fidelity images.