PhoSim Version 3.7 Completed

Dear Science Collaboration Members-

You may be already familiar with the Photon Simulator (PhoSim), but if not-- PhoSim is the ab initio photon/electron physics simulation tool for optical survey telescopes. It is capable of running on your laptop as well as on high throughput computing platforms and grids. It may be useful for your future science planning and data challenge practice with LSST. It is straight-forward to make a synthetic catalog of either parameterized model or truth images of your favorite astronomical objects, and then use PhoSim to turn those realistic astronomical FITS images. Behind the scenes PhoSim will draw photons from your objects and propagate those through the atmosphere, telescope, and camera using realistic physics with a photon Monte Carlo approach.

I’m posting this today, since the thirteenth major release of the Photon Simulator (PhoSim) is now completed, tagged, and validated. Its called PhoSim v3.7.

There have been a number of changes that speed up PhoSim more than an order of magnitude. PhoSim also has more refined physics detail in the sky background, clouds, detector, and optical perturbations. PhoSim now can simulate the correct time correlations of various aspects of the turbulence, clouds, and sky background from two or more different PhoSim runs. PhoSim is also continuing to expand the functionality for simulating systems other than LSST: LSST ComCam is fully implemented, DES is fully implemented (see PIN-24), and JWST and WIYN are mostly completed. The documentation on the website has been redone again and should be much more user-friendly with an updated walkthrough and lots more examples.

You can download the new version and get all the documentation here:

Full release notes for v3.7 can be found through the link above. If you have any problems, please file tickets for bugs at the PhoSim site. Feel free to email me more complicated questions as well.

Best Regards,

John Peterson

v3.7.1 is out at the same place

Fixes two bugs related to bright stars.

v3.7.2 is now done at:

it fixes a bug related to the new source ID as a string feature

v3.7.3 is done:

bug in optimization of photons off chip for extended sources

v3.7.6 is now completed. it fixes a bug in the bright star optimization that was compiler-dependent.

v3.7.8 is posted. it fixes a bug with bright extended galaxies triggering the optimizer which results in non-poissonian noise in some situations.

v3.7.10 is posted. fixes multithreading of random number sequences and significantly improves performance when using large numbers of threads.

v3.7.11 is released and fixes v3.7.10

v3.7.12 has more multithreading performance fixes

v3.7.13 is even better

v3.7.14 is out.

We have created a primer on PhoSim. This is a document intended for LSST science collaboration members who are interested in using PhoSim but are not familiar with the full set of LSST terminology and simulation data products. The primer leads a user through the installation of PhoSim, the software and data files needed as inputs, and a summary of the data products. We will attempt to update this primer as needed based on comments and feedback.

PhoSim Primer v0.21.pdf (986.3 KB)

Great! Thanks, Joshua and Elle.