LGSAO Planning Tools Tutorial

This page describes how to use the IDL planning tools available on the Keck LGSAO software distribution page. The programs are IDL routines and functions, distributed as ASCII files. Download any programs you want to a directory on your local computer, and make sure the directory is in your IDL search path. Each program has a header describing the syntax and options. Please feel free to modify these programs as you deem useful. Many of these programs require subroutines found in the IDL Astronomy User's Library, and IDL version 5.4 or higher.

Start with a Keck format starlist of your favorite scientific targets, for example a file called targets.lst. To search these targets for tip-tilt reference stars, type the IDL command
IDL> FINDTTREF, 'targets.lst'
The program uses an HTML interface with the VIZIER database to search for USNO-B1.0 stars near your targets, and will output to the command line a new target list with these stars included in the correct format. Alternately, a second input string will be interpreted as an output filename, for example
IDL> FINDTTREF, 'targets.lst', 'lgstargets.lst'
There is also an option to output the 2MASS K magnitude for the TT references and check whether some of them have been flagged as extended source or nearby an extended source in the 2MASS catalog:
IDL> FINDTTREF, 'targets.lst', /check2mass

If you would like to find IR-bright PSF stars with the same TTref-target geometry, then you can further process this starlist as follows:
IDL> FINDLGSPSF, 'lgstargets.lst', 'lgstargets_with_psfs.lst'

Once you have identified tip-tilt stars for your targets, you should check the position angle they can be observed at using the online guide star offset planning tool.

The starlists output by the above programs are in the correct format for submission to the LGSAO operations staff, >3 work days prior to your observing run.

. For more information please contact your support astronomer.