Prepping for Daophot and Allstar

The calm before the storm?
December 03, 2007


Before beginning daophot, we must prepare a series of files.

1. The Image Files

Luckily, we have updated daophot and it now acccepts fits images!
Please note that during the course of the photometry, we will make a series of potentially large ascii files as well as making at least 2 copies of the original fits image. Please make sure you have enough free disk space to do this. The errors output by the program when the disk is full are quite difficult to interpret correctly.

2. The OPTions Files

Daophot and Allstar each require a file that contains a series of image specific parameters. These files can be automatically generated with an IDL program written by David Nidever.

However, the headers for the Fan Mountain data contain none of the required information. So, we're going to do this the old fashioned way.

Tony Sohn wrote a Fortran script, mkopt.f , that will create the opt files for daophot and allstar. This code requires a very specific preparation file that we nominally call night#.log. In this file you will collect a series of image parameters that will be complied into the opt files by mkopt.f .

The file has a very specific format :
		  Image     exptime    gain  rdnoise   FWHM   Hi-limit Filters
		   Name       (s)    (e/ADU)   (e)   (pixels)  (ADU)
		--------------------------------------------------------------
		obj516_1      5.000    1.30     5.4    5.20    60000.    V
		obj516_2      5.000    1.40     5.5    5.20    60000.    V
		obj516_3      5.000    1.50     5.5    5.20    60000.    V
		obj516_4      5.000    1.40     5.3    5.20    60000.    V
	
There are a few things to note. A CAVEAT: It is very tempting to take the saturation limit to be the actual limiting count of the amplifier. In practice, however, this is not the actual saturation limit of the stars.

Once this file is put together you can compile and run mkopt.f:
		> mkopt
		 Log file ?
		Pal11.log
	
Now you will have a obj????.opt and obj????.als.opt files for each image in your file. Daophot and Allstar look for these files as daophot.opt and allstar.opt respectively. Thus you will need to change the name of the file for each run in daophot.

The obj????.opt file is for Daophot. You should recognize some of your inputs in the .log file for mkopt:
		RE =     3.79
		GA =     1.40
		LO =     7.00
		HI = 60000.00
		FW =     2.70
		TH =     3.50
		LS =     0.20
		HS =     1.00
		LR =    -1.00
		HR =     1.00
		WA =    -2.00
		FI =     2.70
		PS =    10.80
		VA =     2.00
		AN =    -6.00
		EX =     5.00
		PE =     0.75
		PR =     5.00
	
The key fields to note are: The obj????.als.opt files are for Allstar:
		FI =     2.70
		IS =     1.70
		OS =    11.80
		RE =     1.00
		WA =     0.00
		PE =     0.75
		PR =     5.00
		CR =     2.50
		CE =     6.00
		MA =    50.00
	


3. The photo.opt file

The photo.opt file is a list of apertures for aperture photometry to be performed in daophot. Daophot will read in this file automatically if it has the name photo.opt. The default file is adequate for our purposes here:
		A1 =  3.0000
		A2 =  3.7965
		A3 =  4.8046
		A4 =  6.0803
		A5 =  7.6947
		A6 =  9.7377
		A7 = 12.3232
		A8 = 15.5952
		A9 = 19.7360
		AA = 24.9762
		AB = 31.6077
		AC = 40.0000
		IS = 45.0000
		OS = 50.0000