Import Aperture Definitions from a Text File into AstroImageJ

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Import Aperture Definitions from a Text File into AstroImageJ

A list of RA/Dec coordinates for all of the stars to be measured can be imported into AIJ. To create an example file to give a template showing the required input format, open a plate-solved image (or plate-solve an image). Then in multi-aperture enable "Use RA/Dec to locate apertures...", define 3-4 apertures, and press enter to perform the photometry. The results are not important, but the last step records the apertures in AIJ memory. Now go to Image_Display->File->"Export Apertures to RA/Dec list..." to create an example RA/Dec file. Modify this file with a text editor and include one line for each star you want to measure.

After creating your the desired aperture input file, load the file using Image_Display->File->"Import Apertures From RA/Dec list...". Now start multi-aperture and make sure "Use previous 'N' apertures" and "Use RA/Dec to locate apertures" is enabled. Press "Place Apertures" and then <enter> to start the photometric measurements.

Here is an example of what the RA/Dec input file should look like:

#RA in decimal or sexagesimal HOURS
#Dec in decimal or sexagesimal DEGREES
#Ref Star=0,1,missing (0=target star, 1=ref star, missing->first ap=target, others=ref)
#Centroid=0,1,missing (0=do not centroid, 1=centroid, missing=centroid)
#Apparent Magnitude or missing (value = apparent magnitude, or value > 99 or missing = no mag info)
#Add one comma separated line per aperture in the following format:
#RA, Dec, Ref Star, Centroid, Magnitude
06:30:31.870, +29:42:27.34, 1, 1, 99.999
06:30:32.781, +29:40:20.38, 0, 1, 99.999
06:30:22.613, +29:44:42.19, 0, 1, 99.999
06:30:00.055, +29:46:06.79, 0, 1, 99.999
06:29:48.332, +29:38:14.22, 0, 1, 99.999

If your images are aligned, a similar process can be followed to save the apertures in x,y coordinates by exporting the apertures using Image_Display->File->"Save Apertures". The order of the entries in the file is not important. Any of the items, except x,y aperture locations, can be left out of the file and defaults will be used. After modifying the apertures file, open the defined apertures using Image_Display->File->"Open Apertures". This file format is different in that each listed parameter that corresponds to individual aperture specifications contains the data for all stars in a comma separated list. The order of the items in the file is not important, but the order of the stars in each item must be the same for all items in the file. Here is an example file showing the correct format for 5 apertures:

#AstroImageJ Saved Apertures
#Mon Apr 03 03:59:43 EDT 2017