potpyri.primitives.solve_wcs

WCS solution using astrometry.net and Gaia DR3 alignment.

Provides coarse solution via solve-field and fine alignment by matching detected sources to Gaia. Writes RADISP/DEDISP and updated WCS to FITS. Authors: Kerry Paterson, Charlie Kilpatrick.

Functions

align_to_gaia(file, tel[, radius, ...])

Refine WCS by matching detected sources to Gaia DR3 and fitting WCS.

clean_up_astrometry(directory, file, exten)

Remove astrometry.net temporary files (.axy, .corr, .solved, .wcs, etc.).

get_gaia_catalog(input_file[, log])

Query Gaia DR3 for stars in the field; return filtered catalog table.

solve_astrometry(file, tel, binn, paths[, ...])

Run astrometry.net (solve-field) to get coarse WCS; optionally use custom index.
potpyri.primitives.solve_wcs.align_to_gaia(file, tel, radius=0.5, max_search_radius=<Quantity 5. arcsec>, save_centroids=False, min_gaia_match=7, log=None)[source]

Refine WCS by matching detected sources to Gaia DR3 and fitting WCS.

Parameters:

  • file (str) – Path to FITS file with WCS (e.g. after solve_astrometry).

  • tel (Instrument) – Instrument instance.

  • radius (float, optional) – Gaia query radius in degrees. Default is 0.5.

  • max_search_radius (astropy.units.Quantity, optional) – Match radius for source-Gaia matching. Default is 5 arcsec.

  • save_centroids (bool, optional) – If True, save centroid table. Default is False.

  • min_gaia_match (int, optional) – Minimum number of Gaia matches required. Default is 7.

  • log (ColoredLogger, optional) – Logger for progress.

Returns:

True if alignment succeeded and WCS was updated, False otherwise.

Return type:

bool

potpyri.primitives.solve_wcs.clean_up_astrometry(directory, file, exten)[source]

Remove astrometry.net temporary files (.axy, .corr, .solved, .wcs, etc.).

Parameters:

  • directory (str) – Directory containing the files.

  • file (str) – Base filename (with extension); exten is replaced to form temp names.

  • exten (str) – File extension (e.g. ‘.fits’) to replace with .axy, .corr, etc.

Return type:

None

potpyri.primitives.solve_wcs.get_gaia_catalog(input_file, log=None)[source]

Query Gaia DR3 for stars in the field; return filtered catalog table.

Uses header RA/DEC to define field; filters by PSS, Plx, PM.

Parameters:

  • input_file (str) – Path to FITS file; header used for CRVAL1/CRVAL2 or RA/DEC.

  • log (ColoredLogger, optional) – Logger for progress and errors.

Returns:

Filtered Gaia DR3 table (PSS>0.99, Plx<20, PM<10), or None if empty, or False if coordinates could not be parsed.

Return type:

astropy.table.Table or None or False

Raises:

Exception – If Gaia query fails after retries.

potpyri.primitives.solve_wcs.solve_astrometry(file, tel, binn, paths, radius=0.5, replace=True, shift_only=False, index=None, log=None)[source]

Run astrometry.net (solve-field) to get coarse WCS; optionally use custom index.

Parameters:

  • file (str) – Path to FITS file to solve.

  • tel (Instrument) – Instrument instance (name, get_pixscale).

  • binn (str) – Binning string (e.g. ‘22’) for pixel scale.

  • paths (dict) – Paths dict (source_extractor key for solve-field).

  • radius (float, optional) – Search radius in degrees. Default is 0.5.

  • replace (bool, optional) – If True, write WCS into original file; else write .solved.fits.

  • shift_only (bool, optional) – If True, only update CRPIX/CRVAL. Default is False.

  • index (str, optional) – Path to custom index file or directory for solve-field.

  • log (ColoredLogger, optional) – Logger for progress.

Returns:

True if solve succeeded, False otherwise.

Return type:

bool