verify_astrometry
Verify an image's astrometric solution by measuring how well it reproduces sky positions, comparing detected stars to Gaia DR3 and reporting deviation statistics.
Instructions
Measure how well an open image's astrometric solution reproduces the sky, with the engine of PixInsight's AstrometricSolutionVerifier script (PixInsight 1.9.5 or later), run without its dialog: no deviation map, graphs, files or new windows, and the image is not modified. Every detected star is PSF-fitted, placed on the sky with the image's solution and compared with its Gaia DR3 star at the observation time. The result (JSON) gives the star counts (detected, PSF-fitted, matched, rejected by sigma clipping), the catalogue and its limit magnitude, the deviations (median, sigma, rms, 90th and 99th percentile, maximum) in pixels and arcseconds over the stars kept after sigma clipping and over all matched stars, the median bias, and the grid cell with the largest median deviation (cells with fewer than 3 matched stars are skipped) with its column, row and centre in image pixels. The view needs an astrometric solution.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| view_id | Yes | View ID to verify | |
| magnitude | No | Catalogue limit magnitude used when auto_magnitude is false (script default 16) | |
| grid_cells | No | Number of grid cells along the largest image dimension, 1 to 255 (script default 8) | |
| auto_magnitude | No | Choose the catalogue limit magnitude automatically (script default true) | |
| rejection_sigma | No | Sigma-clipping factor on the deviations; matched stars beyond median + factor x sigma are left out of the retained statistics and the grid, 0 disables (script default 5) | |
| matching_tolerance | No | Maximum distance in pixels between a detected star and its catalogue position for a match (script default 3) |