piastrometry program description

1. General description

piastrometry is a program for finding astrometric transformation (x,y)->(RA,DEC) and calculating of coordinates of all stars stored in mag file into
(RA,DEC) and writing results to so called ast file

piastrometry -h

In the later section each option will be described in detail , program is called :

piastrometry mag_file ast_file output.cfg OPTIONS

2. Program options


Option Name
 Description
 DEFAULT
-to_fits
 saves astrometry transformation to specified fits file, use in scan astrometry to save transformation for later making parts
not set
-timeout
 timeout in seconds
 INFINITY
-verb
 verbose mode
 not set
-ord
 order of transformation polynomial, best setting is 4
 1
-errf
 sets value of global variable MAX_AST_ERR_FATAL ( default value 0.6/2 = 0.3 ) , which means maximum allowable astrometric error ( in pixels ), used in :
1/ loop break condition - astrometry stops when ast_err<=MAX_AST_ERR_FATAL*fwhm AND radius < MAX_GET_RADIUS*fwhm
 0.3

in asas-pipeline  value is
0.6
-err
 sets value of global variable MAX_AST_ERR ( default value 0.3/2 = 0.15 ), which means maximum allowable astrometric error ( in pixels ), it is used for :
1/ loop break condition - astrometry stops when error ( ast_err < MAX_AST_ERR*fwhm )
 0.15

in asas-pipeline values is
0.3
-pixscale
 number of seconds in single pixel ( specific for camera ) ,  for k2a,k2b 59.5 was the best value
-fi
 angle of orientation
 0
-init_header_astro
 This is option for using astrometry saved in header file ( if present ) as starting point for astrometry procedure , can be a little bit faster ( comparison of old and new version is given here But it is not very significant improvement, it was tested on night 20060919 with fast photometry mag files, and it taken 9 hours in old version and 8h50m in new version .... !!! WARNING : be cerful with this option it may cause that astrometry will converge worse than without this option, it can be try in re-try but rather not in the first iteration !!!
no set