4.1 An Introduction to Pipe-lining

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Chp 4 | 4.1 | 4.2 | - 4.2.1 | - 4.2.2 | - 4.2.3 | - 4.2.4 | - 4.2.5 | - 4.2.6 | - 4.2.7 | - 4.2.8 | - 4.2.9 | - 4.2.10 | 4.3 | - 4.3.1 | - 4.3.2 | - 4.3.3 | 4.4 | - 4.4.1 | - 4.4.2 | - 4.4.3 | - 4.4.4 | - 4.4.5 | - 4.4.6 | - 4.4.7 | - 4.4.8 | - 4.4.9 | - 4.4.10

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4.1 An Introduction to Pipe-lining

“The process of finding the apparent magnitude of a star can be surprisingly complex even with a technique as simple as CCD aperture photometry” (Mighell, 1999). First the simplistic task of file preparation must take place (i.e., de-biasing and flat-fielding), however even these simple tasks can be come complicated if the image format needs to be updated. Once this has been accomplished the more complex assignment of photometry can take place. Itemised below is a list of the tasks required to be carried out to perform PL photometry:

Find the star
Centre an aperture of N_A pixels on the star
Add up the counts within the aperture: S_A
Determine the nearby background flux B
Determine the instrumental magnitude: m' = -2.5log ₁₀[S_A - N_AB]
Determine the zeropoint correction: m'
Compute the zeropoint-corrected instrumental magnitude: m = m' + m'

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