Most Recent News: (12/14/18) PhoSim v5.0.2 is available! Comprehensive Opto-Mechanical Capabilities! See the detailed announcements.

The Photon Simulator (PhoSim) is a set of extremely fast photon Monte Carlo codes used to calculate the physics of the atmosphere and a telescope & camera in order to simulate realistic optical/IR astronomical images. It does this using modern numerical techniques applied to the physical response of photons (and electrons) to comprehensive physical descriptions of the atmosphere, telescope, and camera. After these detailed physics calculations, PhoSim simply generates images by collecting electrons into pixels. This photon simulation [movie] shows the photon Monte Carlo method used in the simulation where photons and electrons are physically propagated through the system using appropriate approximations. The physics of the site/telescope/camera includes: hydrodynamic-based descriptions [movie] of the atmosphere, elasticity theory calculations [movie] of optics deformations, and electrostatic simulations [movie] of sensors. Since PhoSim is a physics-based code, it is written independent of the telescope/camera/site system, so there are a number of present, past, and future observatories implemented as different input configuration files. Despite the physics detail, PhoSim is quite fast due to novel efficient numerical techniques and multithreading-- individual astrophysical objects can be simulated in milliseconds, and large fields of objects in minutes to hours depending on the size and depth. The links below describe how to use PhoSim, document detailed technical information about PhoSim, and show several example images.

• User Information:

  • Basic PhoSim Walkthrough (Last Updated 1/17/19)

  • Detailed User Documentation (Last Updated 2/20/19)

  • PhoSim Announcement Page (Last Updated 12/14/18)

• Detailed Technical Documentation:

  • PhoSim First Reference Paper: Peterson et al. 2015, ApJS 218, 14.

  • PhoSim Second Reference Paper: Peterson et al. 2019, ApJ 873, 98.

  • PhoSim Reference Document

  • PhoSim Internal Notes

  • PhoSim Related Publications

• Contact Information:

  • About PhoSim

  • Email Questions to: John Peterson

  • Current Official Support: LSST (NSF) and JWST (NASA)

• Examples:

  • Very large-scale PhoSim images

  • An uncalibrated uiy 13'x6' PhoSim image is below. An explanation for what you are looking at is here.

  • A sequence of 100 exposures of a 13' x 13' field [movie] similar to the example image below.

  • A cumulative sequence of these exposures [movie].

  • A sequence of a smaller 2.5' x 2.5' field [movie].

  • The cumulative sequence of the smaller field [movie] of this smaller field.

  • Sample images to download.

  • Guider simulation [movie]

  • Hubble galaxy sequence

  • Mirror control simulation [movie]