FGS-Sim

Claudio Arena PhD Thesis

Claudio Arena - 2020

Code was adapted, modified and extended, starting from Feiyu Fang initial code.

PHASM201 MSci Project

Feiyu Fang

Twinkle FGS-Sim MSci project, October 2017

Changelog

Version number, Date in ISO 8601 format, Notes on changes

• 1.0. 2017-07-12, Initial version in summer project. Full summer changelog in CHANGELOG-Summer.md.
• 2.0. 2017-07-20, Changed format to be suitable for meaningful testing.
• 2.3. 2017-09-18, Final summer version. Monte Carlo simulations from a Gaussian.
• 3.0.0 2017-11-02
  • v3. Using a PSF instead of a generated Gaussian.
  • Wrote a preliminarily procedural Read.cpp to read PSF data from a Zemax-generated .txt file. Output is a vector<vector>.
  • NB: Input file must be converted from MS-DOS to Unix encoding.
  • Rewrote Read.cpp into a PSF class which imports data from Zemax output into a vector<vector> of photons.
  • Main.cpp now works by taking in a .tsv and calculates the coordinates of the centroid.
• 3.0.1 2017-11-15
  • Added functions to PSF class so that the coordinates of the PSF centre can be specified, for future PSF movement use.
  • This is by taking the original normalised centroid PSF and shifting its centre, replacing empty simels with 0 values.
  • Confirmed working, with the Main.cpp correctly working out the centroid location with no Zodiacal light or readout noise, but these parameters ruin things very quickly.
• 3.0.2 2017-11-23
  • Added functions to generate Brownian motion with a given bias distance and direction in the field of view.
  • MonteCarlo class modified to iterate over this Brownian motion, giving a path of a moving star.
  • NB: This is only while assuming that the PSF stays the same when the star moves around the FOV.
  • Example of Brownian motion simulation:
• 3.1.0 2017-12-13
  • Brownian motion code moved to separate class to allow star movement within a single camera exposure
• 3.2.0 2018-02-22
  • Extracted the needed Zemax PSFs for each field on 2018-02-12.
    • 17 fields were taken, with location of fields shown here.
    • Fields were taken at the centre, halfway out, and on the edge of the CCD. As the CCD is 6 arcmin across, PSFs were taken at -2.9', -1.5', 0', +1.5' and +2.9'.
    • PSF TSVs and images of these PSFs are on Dropbox.
  • Changed run() in MonteCarlo class to output average errors, instead of outputting directly into a CSV.
    • This allows iterations of many Zemax PSFs.
    • Added a public member variable for standard deviation of the errors over a set of iterations, for access and output in Main
  • File handling moved from MonteCarlo to Main.
  • Some fields perform better than others:
  • More Zemax work done.
    • Lens data taken.
    • Diffraction test done, showing that the PSFs are generated properly.
    • Effect of defocus on PSFs found. FWHMs change significantly once the defocus coordinate break is changed by ~0.5mm.
    • The focal plane has a certain natural defocus due to the off-axis tilt, so the focal plane can be re-tilted to partially cancel this.
• 3.2.1 2018-03-21
  • Fixed dark signal bug on Test.cpp, where temperature variation did not have any effect.
  • Made some of the Doxygen documentation clearer