Welcome to the Documentation for MAVISIM

MAVISIM is a Python tool to simulate images generated by the MCAO Assisted Visible Imager and Spectrograph (MAVIS) instrument. MAVIS is an instrument being designed for ESO's VLT AOF (Adaptive Optics Facility, UT4 Yepun) with plans to go on-sky ~2027. For more information on MAVIS visit this link. If you use MAVISIM please cite Monty et al. 2021.

Current Version: 1.1

MAVISIM 1.1 builds on 1.0 with the major difference that it uses an end-to-end (e2e) PSF. The e2e PSFs provide significantly more realism, thus making them the preferable choice. However, some flexibility is lost with v1.1, please see the following "pros" and "cons" lists and the table at the end of this page to decide which version is best for you.

Capabilities

  • Simulate a full stellar field with built-in PSF spatial variability using an end-to-end PSF
  • Optimised for both photometric and astrometric studies
  • Models two major sources of astrometric error introduced by the AO system with full user control over each:
    1. Tip-tilt residuals originating from uncorrected low-order aberrations (in addition to NGS residuals which are built-in
    2. Static field distortion originating from the adaptive optics module

Limitations

  • Monochromatic images only
  • Point source input catalogues only

Previous Version: 1.0

MAVISIM 1.0 is optimised to explore the astrometric capabilities of MAVIS. Specifically, it utilises a Fourier approximation of the MAVIS PSF to simulate a monochromatic image of point sources.

Capabilities

  • Simulate a full stellar field with built-in PSF spatial variability
  • Optimised for astrometric studies
  • Models three major sources of astrometric error introduced by the AO system with full user control over each:
    1. Field variable tip-tilt residuals originating from uncorrected low-order aberrations (dependent on the natural guide star constellation brightness and geometry)
    2. Field variable high-order aberrations originating from the laser guide star constellation and characteristics
    3. Static field distortion originating from the adaptive optics module

Limitations

  • Monochromatic images only
  • Only compatible with an analytical approximate model of the MAVIS PSF using the Fourier method
  • Point source input catalogues only

Dev Version: 1.2

Which Version is Right for Me?

Version 1.0 is designed to give the user the most control over tuning each astrometric error term. Subsequent versions utilising an end-to-end PSF provide more accuracy regarding the PSF but are less tunable. If your aim is to explore the impact of astrometric error terms easily, 1.0 is the version for you, if photometry is your goal checkout versions 1.1 and 1.2 when they're released.

If you're not sure which version has what you need, here is a comparison of the current version with the planned upgrades in future versions.

Version PSF Source PSF Field Variability Wavelength Coverage Scientific Sources User Control
1.0 Fourier Approximation Yes Monochromatic - see PSF database for options Point sources only High
1.1 End-to-end Yes Monochromatic - see PSF database for options Point sources only Intermediate
1.2 dev End-to-end Yes Broadband - see filter and PSF database for options Point sources only Intermediate
2.0 End-to-end Yes Broadband - see filter and PSF database for options Extended objects T.B.D.