Troubleshooting guide

detail the use of both here.
The flmntools tasks fwcheck and fwscan take differences of images, and then run SExtractor on
the central 1250 × 1250 pixel region to determine the average FWHM; sources brighter than 10,000
ADU in the difference image are ignored and objects with FWHM < 1.3 pixels are rejected as cosmic ray
hits. To use these, first enter the flmntools package to get the following prompt:
cl> flmn
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Welcome to FLMNTOOLS - The FLAMINGOS Observing Tools
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tasks included are:
fwcheck - Quickly check the fwhm and display the difference image
fwscan - Compute the fwhm for each frame in a set of observations
fwcheck fwscan
fl>
This package is used at more than one telescope, so on the off-chance that the parameters have been
unlearned, verify the telescope field is set to Mayall (the 4-m):
fl> epar fwscan
PACKAGE = flmntools
TASK = fwscan
root = ugc3371.j Root infile name?
First = 21 First image in set?
Last = 25 Last image in set?
(telesco= Mayall) Telescope(MMT,Mayall,KPNO2.1m)?
(mode = q)
fwscan takes a range of images as inputs, in the form
fwscan <image root name> <First image number> <Last image number>
It computes running difference images from which it computes the FWHM. You can use this to monitor
the seeing during a sequence of observations. To use this for focus runs, e.g.
4mguest@flmn-4m-1a{1} singleimage.pl
4mguest@flmn-4m-1a{2} relative.offset.kpno.pl 10 0
Ask the operator to increment the focus (e.g 50 – 100 units).
Repeat these three steps as necessary, offsetting the telescope back and forth between each image.
Once you've taken 2 or more images epar fwscan to make certain it is setup for the 4-m, then run
fwscan. Here's some sample output:
fl> fwscan p182e.j 1 9
#Main Bkgd 1st
#Frame Frame Average Median Quartile #stars
1 2 0.85'' 0.83'' 0.81'' 51
2 1 0.89'' 0.88'' 0.85'' 49
FLAMINGOS@4-m, Ver. 2.34, 2006 Apr 04 Page 14 of 44