The default value of 'pattern_checking_stars' is 8. When solving 11deg FOV images with 20-30 detected stars against a mag=7 database, I find that solving frequently fails. Increasing 'pattern_checking_stars' to e.g. 12 helps in the few cases I've investigated so far.
Because 'pattern_checking_stars' uses the N brightest detected stars, 8 should have been a reasonable default-- we need more than 4 to allow bright interlopers (e.g. planets) to be skipped, and to deal with brightness variations due to variable stars, different spectral response of the camera vs. the star catalog, etc.
This issue is to track my investigation (and hopefully improvements) around why pattern_checking_stars=8 is often insufficient.
The default value of 'pattern_checking_stars' is 8. When solving 11deg FOV images with 20-30 detected stars against a mag=7 database, I find that solving frequently fails. Increasing 'pattern_checking_stars' to e.g. 12 helps in the few cases I've investigated so far.
Because 'pattern_checking_stars' uses the N brightest detected stars, 8 should have been a reasonable default-- we need more than 4 to allow bright interlopers (e.g. planets) to be skipped, and to deal with brightness variations due to variable stars, different spectral response of the camera vs. the star catalog, etc.
This issue is to track my investigation (and hopefully improvements) around why pattern_checking_stars=8 is often insufficient.