Overview of Today's Class
Introduction to performing inversions in LTE (Local Thermodynamic Equilibrium) with synthetic profiles.
Creation of synthetic profiles with added noise for realism.
Plans to compare outcomes from these profiles against synthesized atmospheres.
Course Materials and Setup
Access to the latest version of the software from the Dropbox folder.
Instructions for installing the software using 'make install'.
Recommendation to create a new folder for each session using the new version.
Creating Input Atmospheres
Utilizing the HSRI atmosphere with adjusted parameters for synthesis.
Output file named 'input.mod' for atmosphere comparison during inversions.
Analysis of atmospheric parameters such as temperature, magnetic field, and microturbulence.
Synthesis and Noise Addition
Synthesis performed for specific calcium lines and the addition of noise to profiles for realism.
Utilization of a normal distribution function to introduce random noise into data.
Separate plotting of profiles for clarity and analysis of the added noise impacts.
Saving Profiles for Inversions
Profiles synthesized from the atmosphere saved for future inversion use.
A second atmosphere created with different parameters for comparison purposes.
Discussion on the importance of noise levels in stock parameters during analysis.
Inversion Process Setup
Initiating a new atmosphere file for the inversion process.
Configuration changes for inversion separated from synthesis for clarity.
Setting parameters such as node configuration and inversion cycle limits for processing.
Running Inversion Calculations
Execution of inversions on profiles, with mentions of code speed and efficiency.
Discussion on threshold values affecting calculations and their implications.
Stressing the importance of proper input atmosphere in generating realistic profiles.
Reviewing Inversion Results
Overview of how to interpret the results from the inversion process.
Final profiles saved along with atmosphere models indicating cycles performed.
Introduction of chi-square evaluation as a measure of inversion success.
Chi-Square Values and Configuration
Two different configurations are yielding close chi-square values, making comparison tricky.
A new column may be added to simplify the comparison of configurations.
A file containing chi-square values is available for analysis.
Log Files and Iteration Issues
A log file tracks chi-square values and design iterations.
The log file may provide hints for convergence issues or code stoppages.
Output Files Review
The current output file structure is being reconsidered to better understand entities.
Future updates will allow computation of the best atmospheric entity results.
Profile Fitting and Comparisons
Input profiles will be compared with their fitted counterparts to assess accuracy.
Observational data is not always available for such comparisons.
Inversion Results and Observations
Initial results from profiles show good fits, especially for photospheric lines.
Chromospheric line fits have variations due to noise, suggesting reduced weight on those observations.
Model Comparison and Error Analysis
Comparisons of models indicate that atmospheric behavior is complex and requires careful analysis.
It is crucial to select the appropriate spectral lines for inversion to enhance accuracy.
Future Improvements and Learning
Next classes will focus on improving inversion results and synthesis processes.
The importance of starting with simpler atmospheric models is emphasized for effective learning.
DeSIRe inversion code online tutorial, Day 5: Inversions of the Stokes profiles in NLTE
DeSIRe inversion code online tutorial, Day 5: Inversions of the Stokes profiles in NLTE