Techniques of
Observational Astronomy
AST3722C
Color Imaging
Color imaging uses many of the techniques required for scientific imaging. It is necessary to apply darks and flats to "lights" (images of the object under observation) and to combine the resulting images. Here we give a quick overview of the process. More details can be found in the book "The Handbook of Astronomical Image Processing" by Berry and Burnell.
The basic process is to get high S/N (signal-to-noise) darks at the same temperature and exposure duration as the lights.
In addition, high S/N flats will be used to normalize the pixel-by-pixel sensitivity of the lights. High S/N darks are needed for the flats as well.
High S/N lights must be produced in each of three colors (R=red, G=green … use V filter, and B=blue). High S/N flats must be produced for each of these colors as well.
Example based on imaging by Group 2 (Tristram and Pepijn) with the 0.46m telescope at RHO.
Brief Outline
· Produce median combined darks for all temperatures and exposure times
· Subtract darks from lights and flats
· Divide lights by flats
· Stack lights to register star images
· Align R,G,B lights and produce color composite image
Instructions for using AIP4WIN
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This page was last edited November 4, 2004 10:38 AM