From download to your first report.

1. Download and verify

   Download the ZIP and checksum. Compare the ZIP’s SHA-256 with the value shown on the download page.

2. Extract the entire package

   Use Windows “Extract All”. Open the extracted Pytheia200_Evaluation folder. It contains Pytheia200.exe, settings.ini, app, runtime, integrity, license, and other files. Keep them together. Do not run from inside the ZIP.

3. Install your separate activation

   Request a license from Orionis. Copy the supplied license.json and license.sig into the package’s license folder. Keep the public key already in that folder.

   Copy the personalized LICENSE.txt into the package root, replacing the generic agreement. Read it: the name and period come from your signed license. Your 30 UTC calendar days begin on issuance.

4. Run the bundled example

   Open PowerShell in the folder containing Pytheia200.exe and run:

   .\Pytheia200.exe

   The default settings.ini selects example/example.dat. The reference fit converges to total RMS 2.5608 arcseconds.

5. Open the outputs

   Open example/output/results_example.html in a browser. The fitted coefficients are in example/output/coefficients_example.txt. Check the report’s licensed-recipient attribution.

6. Use your own observations

   Edit settings.ini or keep another settings file for your telescope. Relative data and output paths are resolved from that settings file’s folder.

   .\Pytheia200.exe "C:\My Telescope\mytelescope.ini"

   Select azel or hadec, your terms, and the input data. HA/Dec requires site latitude. Consult the bundled documentation before creating additional terms or using results operationally.

Evaluate an existing model

After running the bundled fit, open PowerShell in the package folder and run:

.\Pytheia200.exe --evaluate example\example.dat example\output\coefficients_example.txt settings.ini

This evaluates the supplied coefficients without refitting or changing the coefficient file. It prints rigorous and first-order residual statistics and writes example/output/example_evaluate_residuals.csv.

To check coefficients against independent observations, use:

.\Pytheia200.exe --evaluate "C:\My Telescope\night2.dat" "C:\My Telescope\coefficients_night1.txt" "C:\My Telescope\evaluation.ini" --external

The settings file is optional; the default is the package settings.ini. Command-line relative paths are resolved from the current PowerShell folder. Paths inside the settings file are resolved from that settings file.

Only terms in the coefficient file are evaluated. Use coefficients with matching mount mode, term definitions, site latitude and auxiliary settings. Version 2.1.1 retains the corrected 2.1.0 scientific definitions.

Use --external when coefficients were fitted on other observations. It removes no fitted-parameter degrees of freedom from population SD; it does not change the residuals or RMS.

CSV residuals are in arcseconds, with the sign predicted minus observed. Repeating evaluation with the same data basename and output folder replaces the CSV; use separate output folders to retain comparisons.

If the program stops

Maintenance build 26L33 corrects the identified pandas chained-assignment warning during coordinate loading. The README identifies the maintenance build and its validation scope. If a similar diagnostic appears, retain the complete console output and contact Orionis; do not modify bundled dependencies or suppress warnings.

For help, email support@orionisgroup.com with the exact console output and your settings, omitting confidential observation data where appropriate.

Startup and model settings

The launcher displays the signed recipient and expiry before checking the installation. A cold start on a mechanical hard drive can take several minutes; progress messages show that verification is continuing.

Select terms in settings.ini using the readable term catalogue. Before reusing older coefficients, read the 2.1.0 scientific upgrade guidance. The TCS modules apply fitted models in a control system.