SAOImage DS9 is an astronomy FITS file viewing and analysis software. It is extremely useful for rescaling the intensities of an image or fitting the intensities to a particular function such as a squared or logarithmic relationship, colour maps can be applied to the images too. These adjustments help bring out previously hidden detail in areas of the image.
One tool that is of particular use when measuring resolving power or seeing is the 'projection tool' found under Region>Shape>Projection.
Once selected, the user can draw a line across a section of interest and a plot of intensity along the length of the line will be produced. Further more, by selecting the projection line and dragging out the middle node, the thickness of the line is increased over which the projection will be averaged (especially useful for averaging out noise).
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| An image of Saturn taken on the LX200. The image has been square root scaled, mapped with the 'cool' colour map and a projection drawn across the length of Saturn. The projection clearly shows that the gap between the rings and the main body of Saturn can be resolved. |
