PhoSim v6.1 completed

The 24th major release of the Photon Simulator (PhoSim) is completed, tagged, and validated as PhoSim v6.1!

See the end of this message if you are new to PhoSim.

Some highlights:

  1. PhoSim v6.1 has several new improvements.

    -The largest improvement is the complete ab initio physical implementation of coating interactions on all optical surfaces including a/r coatings, protective coatings, etc. and some augmentation of multilayer physics. All coatings also allow for inhomogenous thickness, and the light responds accordingly.

    • We also updated various measuring tools, added more example catalogs, flexibility in the SED normalizing point, adjusted airglow levels, spectra, and variability based on careful photometric studies, implemented correlated time-dependence of aerosol distributions, added absorption in materials, and streamlined the installation scripts and dependencies to work on more systems.
      -The wide-field survey telescope (WFST) was implemented (W. Luo).
      -Various improvements were made to the Pan-STARRS implementation (G. Magnier).
      -The WIYN telescope coatings and contamination levels were implemented.
      -The Rubin optics coatings and contamination levels were completely redone replacing old methods.
      -There are a number of bug fixes and many new optimizations that improve performance as well.
  2. All documentation (tutorials, documentation, links to reference material, etc.) and instructions to get the code are at:

  3. The fifth reference paper was completed. Follow the technical links for more information.

  4. We are also creating more tools/APIs related to machine learning/AI.

  5. We’re attempting to facilitate the implementation of many more telescopes much more rapidly, which some of the improvements simplify. To do this, we are building a number of tools as well as simplifying the interfaces for implementation of telescopes. Please contact us if you want to collaborate on any telescope.

Please file tickets for bugs at the main site. And please email your feedback, questions, or collaboration ideas!



PhoSim is an ab initio Monte Carlo simulation code of the IR/optical/UV/X-ray physics of astronomical observations. PhoSim fundamentally creates emergent measurement errors (photometric/astrometric/PSF size/shape) imprinted in realistic images by using basic physics rather than using models/parameterizations. PhoSim is also extremely fast with novel numerical algorithms, advanced Monte Carlo techniques, and efficient multithreading methods. It can be run on laptops/desktops as well as in high performance computing environments. Major improvements in the past 5 years have been: 1) full implementation of opto-mechanical physics, 2) complete sensor electrostatics physics, 3) self-consistent atmosphere global hydro-based representations, 4) a variety of optical surface interface physics 5) generalizations and implementations for many different telescopes, 6) simplification of the user interface, 7) an internal astronomical catalog generator & operations capabilities. There is a major release (vX.Y) once or twice a year. The major releases include hundreds of revisions. Between releases, there are intermediate patches (vX.Y.Z). These fix urgent bugs. There are hundreds of pages of documentation that are routinely updated, 22 user tutorials, and the 5 reference papers. There are now 33 implemented telescopes, and more in development from at least 5 different teams. In addition, if you don’t want to run PhoSim yourself, there is a substantial amount of example images which includes the PhoSim Rubin Survey (PRS).