Optimal Spectrum Extraction Package for IDL

Design, supervision, contact:
Dr. Joseph Harrington
326 Space Sciences Building
Cornell University
Ithaca, NY 14853-6801

John Dermody (Cornell) Version 0.3.0 08 Jul 04
Dara Zeehandelaar (Cornell)


This package extracts a spectrum from a reduced spectrograph data frame using the optimal algorithm described in "An Optimal Extraction Algorithm for CCD Spectroscopy" (K. Horne, 1986, PASP 98:609-617). The initial flattening and bias subtraction are to be done outside the package, along with any sky subtraction and calculations of the initial variance estimates. The base procedure fits the background, generates a profile estimate, masks cosmic rays, and extracts the optimal spectrum. Extensions to the paper's algorithm include Gaussian and running average fits for the profile construction. There is also an option to straighten the data trace before estimating the profile.


Copy the optspecextr directory to your IDL function directory, where it can be seen by the IDL program.

To test your installation, change into a directory where you can write files and run testoptextr. The following four lines should appear on your screen if things are working normally:

	Creating simple test data
	Creating default test data
	PASS - Simple Frame
	PASS - Default Frame

Package Contents

	README	- the place to start
	doc	- directory containing HTML-format documentation
	images	- directory containing example and test images
	*.pro   - IDL functions
Algorithm and Function List
Getting Started
Fine-Tuning, Progress Reports, Run-Time Plots
Trace Straightening Tricks
Frequently-Asked Questions