WFI Detector Noise Generator (NG)
Bernard Rauscher has created a WFI Detector Noise Generator (NG) (written in Python v.3.4) to simulate Roman Space Telescope's Wide Field Imager (H4RG+SIDECAR) detector noise. An associated paper describes the generator. A Python notebook named "01_README.ipynb" that comes with the code describes the generation of WFI noise images in Example 2.2.1. The output of the code is a noise-containing FITS image or a three-dimensional noise-containing datacube. The simulated noise components include:
- white read noise;
- residual bias drifts;
- pink (1/f) noise;
- alternating column noise;
- picture frame noise.
Noise Generator includes uncorrelated, correlated, stationary, and non-stationary noise components. It correctly accounts for end of row and end of frame timing gaps.
Noise Generator can be used as a starting point for simulating astronomical scenes by adding dark current, scattered light, and astronomical sources into the results. To simulate a scene that contains astronomical sources, background light, instrument glow, and dark current, one would begin by using Noise Generator to generate an empty noise datacube. The noise cube would contain no charge from any source whatsoever. One would then use separate software to simulate the astronomical scene and effects of the telescope. Finally, as charges are integrated in pixels, they should be summed into the datacube at the correct pixel locations and arrival times.
Please note that you must have the following modules loaded in Python 3 before the generator works: astropy, datetime, numpy, os, scipy, and warnings.