How to Create a Calibrated Modal Amplitude for Modal History
This guide helps you to create a calibrated modal amplitude for modal history push-pull.
Normally one can use the old one.
The first step is to perform an AO calibration with a modal history based on an old modal amplitude. If there are no previous modal amplitudes you can use a constant vector, for example 1. The Interaction Matrix object records also the RMS slopes for each mode and each WFS. It is possible to use this vector to calibrate the modal amplitude to get a new modal history and a new Interaction Matrix where each modes is measure with the same RMS value.
If RMS slopes are too small (dominated by noise) or too large (signal saturation) it is possible to adjust the Modal Amplitude dividing the vector with a "constantFactor".
To get the new Modal Amplitude:
For example MODAL_AMP_TAG 20151211_164800_rms0.10 should provide on LGSW a constant slopes RMS of 0.1 for each mode.
- 24 Feb 2018